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Tiwary P, Kukreti S, Shridhar V, Abhinav A, Rana S, Arunachalam K, Singh V. Assessment of Black Carbon, optical properties and aerosol radiative forcing at Pranmati basin Himalayan critical zone observatory. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 933:173050. [PMID: 38734083 DOI: 10.1016/j.scitotenv.2024.173050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 04/09/2024] [Accepted: 05/06/2024] [Indexed: 05/13/2024]
Abstract
The study aimed to understand the optical properties of Black Carbon (BC) and radiative forcing over a data deficient Himalayan region focusing on critical zone observatory employing ground-based measurements by Aethalometer for BC and satellite retrieval techniques for optical properties during mid-May-June 2022 and January-May 2023. BC mass concentration ranged from 0.18 to 4.43 μgm-3, exhibit a mean of 1.47 ± 0.83 μgm-3 with higher summer concentration (1.51 ± 0.94 μgm-3) than winter (1.39 ± 0.61 μgm-3). The average Absorption Ångström Exponent observed to be significantly higher than unity (1.77 ± 0.31) over the studied high-altitude Himalayan region, suggesting the dominance of biomass-burning aerosol. Higher aethalometer derived compensation parameter (K) in winter suggesting locally originated BC while, lower K value in summer suggesting aged BC transported from Indo-Gangetic Plains. Optical properties calculated from "Optical Properties of Aerosol and Cloud" (OPAC) model are used in the "Santa Barbara DISORT Atmospheric Radiative Transfer" (SBDART) model to calculate the aerosol Direct Radiative Force (DRF). The entire studied period is characterized by the predominance of absorbing aerosols, particularly BC, increasing Aerosol Optical Depth, Asymmetric Parameters and decreasing Single Scattering Albedo, leading to a considerable increase in atmospheric radiative forcing (+0.9 Wm-2, top of atmosphere) and Heating Rate (0.36 KDay-1). The mean radiative forcing within atmosphere during summer was higher (+14.29 Wm-2) relative to the winter (+12.00 Wm-2), emphasizing the impact of absorbing aerosols on regional warming and potential glacier melting in the Himalayas at a faster rate. Urgent policy consideration for the reduction of absorbing aerosols is highlighted, recognizing the critical roles of Black Carbon in the changing behaviour of Critical Zone observatory. The study's data serve as a valuable resource to understanding and addressing uncertainties in climate models, aiding effective policy implementation for Black Carbon reduction.
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Affiliation(s)
- Priyanshu Tiwary
- School of Environment and Natural Resources, Doon University, Dehradun 248001, India
| | - Saurabh Kukreti
- School of Environment and Natural Resources, Doon University, Dehradun 248001, India
| | - Vijay Shridhar
- School of Environment and Natural Resources, Doon University, Dehradun 248001, India.
| | - Akash Abhinav
- School of Environment and Natural Resources, Doon University, Dehradun 248001, India
| | - Shakuntala Rana
- School of Environment and Natural Resources, Doon University, Dehradun 248001, India
| | - Kusum Arunachalam
- School of Environment and Natural Resources, Doon University, Dehradun 248001, India
| | - Vimal Singh
- Department of Geology, Delhi University (DU), New Delhi 110007, India
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Sharma A, Srivastava S, Mitra D, Singh RP. Spatiotemporal distribution of air pollutants during a heat wave-induced forest fire event in Uttarakhand. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:110133-110160. [PMID: 37779123 DOI: 10.1007/s11356-023-29906-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 09/12/2023] [Indexed: 10/03/2023]
Abstract
Prevailing dry conditions and rainfall deficit during the spring season in North India led to heat wave conditions which resulted in widespread and intense forest fire events in the Himalayan state of Uttarakhand during April 16-30, 2022. A total of 7589 active fires were detected by VIIRS during the second half of April 2022 compared to 1558 during the first half. The TROPOMI observed total column values of CO and NO2 increased by 4.4% and 11.7%, respectively during April 16-30, 2022 with respect to April 1-15, 2022. A noticeable increase in surface level concentration of trace gases was also observed at Dehradun. In situ measurements of CO, NOx, and O3 during April 16-30, 2022 show an increase of 133, 35, and 6% compared to previous year observations during the same period. Weather Research and Forecasting model with chemistry (WRF-Chem) is utilized to quantitatively estimate the contribution of this event on the distribution of air pollutants over this state. The model results were evaluated against ERA5 reanalysis, upper air soundings, and TROPOMI-retrieved total column density (TCD) of CO, NO2, and O3. Two simulations with (Fire) and without (NoFire) biomass burning emissions input were performed to quantify the contribution of forest fires to the concentration of trace gases and particulates. The CO, NO2, and O3 emitted/produced from forest fire over Uttarakhand during April 2022 contributed approximately 39.95, 35.73, and 9.97% to the surface concentration of respective gas. In the case of aerosols, it was around 71.20, 71.44, and 33.62% for PM2.5, PM10, and BC respectively. The vertical profile analysis of pollutants revealed that extreme forest fire events can perturb the distribution of air pollutants from the surface up to 450 hPa.
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Shabin M, Kumar A, Hakkim H, Rudich Y, Sinha V. Sources, sinks, and chemistry of Stabilized Criegee Intermediates in the Indo-Gangetic Plain. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 896:165281. [PMID: 37406701 DOI: 10.1016/j.scitotenv.2023.165281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 06/08/2023] [Accepted: 07/01/2023] [Indexed: 07/07/2023]
Abstract
Night-time oxidation significantly affects the atmospheric concentration of primary and secondary air pollutants but is poorly constrained over South Asia. Here, using a comprehensively measured and unprecedented set of precursors and sinks of Stabilized Criegee Intermediates (SCI), in the summertime air of the Indo-Gangetic Plain (IGP), we investigate the chemistry, and abundance in detail. This study reports the first summertime levels from the IGP of ethene, propene, 1-butene, cis-2-butene, trans-2-butene, 1-pentene, cis-2-pentene, trans-2-pentene, and 1-hexene and their possible roles in SCI chemistry. Ethene, propene, and 1-butene were the highest ambient alkenes in both the summer and winter seasons. Applying chemical steady-state to the measured precursors, the average calculated SCI concentrations were 4.4 (±3.6) × 103 molecules cm-3, with Z-CH3CHOO (55 %) as the major SCI. Z-RCHOO (35 %) and α-pinene derived PINOO (34 %) were identified as the largest contributors to SCI with a 7.8 × 105 molecules cm-3 s-1 production rate. The peak SCI occurred during the evenings. For all SCI species, the loss was dominated (>50 %) by unimolecular decomposition or reactions with water vapor or water vapor dimer. Pollution events influenced by crop burning resulted in significantly elevated SCI production (2.1 times higher relative to non-polluted periods) reaching as high as (7.4 ± 2.5) × 105 molecules cm-3 s-1. Among individual SCI species, Z-CH3CHOO was highest in all the plume events measured accounting for at least ~41 %. Among alkenes, trans-2-butene was the highest contributor to P(SCI) in plume events ranging from 22 to 32 %. SCIs dominated the night-time oxidation of sulfur dioxide with rates as high as 1.4 (±1.1) × 104 molecules cm-3 s-1 at midnight, suggesting that this oxidation pathway could be a significant source of fine mode sulfate aerosols over the Indo-Gangetic Plain, especially during summertime biomass burning pollution episodes.
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Affiliation(s)
- Muhammed Shabin
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S Nagar, Manauli PO, Punjab 140306, India
| | - Ashish Kumar
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S Nagar, Manauli PO, Punjab 140306, India
| | - Haseeb Hakkim
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S Nagar, Manauli PO, Punjab 140306, India
| | - Yinon Rudich
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Vinayak Sinha
- Department of Earth and Environmental Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, S.A.S Nagar, Manauli PO, Punjab 140306, India.
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Karim I, Rappenglück B. Impact of Covid-19 lockdown regulations on PM 2.5 and trace gases (NO 2, SO 2, CH 4, HCHO, C 2H 2O 2 and O 3) over Lahore, Pakistan. ATMOSPHERIC ENVIRONMENT (OXFORD, ENGLAND : 1994) 2023; 303:119746. [PMID: 37016698 PMCID: PMC10062718 DOI: 10.1016/j.atmosenv.2023.119746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 03/21/2023] [Accepted: 03/24/2023] [Indexed: 06/19/2023]
Abstract
The COVID-19 pandemic altered the human mobility and economic activities immensely, as authorities enforced unprecedented lock down regulations. In order to reduce the spread of COVID-19, a complete lockdown was observed between 24 March - 31 May 2020 in Pakistan. This paper aims at investigating the PM2.5, AOD and column amounts of six trace gases (NO2, SO2, CH4, HCHO, C2H2O2, and O3) by comparing periods of reduced emissions during lockdown periods with reference periods without emission reductions over Lahore, Pakistan. HYSPLIT cluster trajectory analyses were performed, which confirmed similar meteorological flow conditions during lockdown and reference periods. This provides confidence that any change in air quality conditions would be due to changes in human activities and associated emissions. The results show about 38% reduction in ambient surface PM2.5 levels during the lockdown period. This change also positively correlated with MODISDB and AERONETAOD data with a decrease of AOD by 42% and 35%, respectively. Reductions for tropospheric columns of NO2 and SO2 were about 20% and 50%, respectively during a semi lockdown period, while no reduction in the CH4, C2H2O2, HCHO and O3 levels occurred. During the lockdown period NO2, O3 and CH4 were about 50%, 45% and 25% lower, respectively, but no reduction in SO2, C2H2O2 and HCHO levels were noticed compared to the reference lockdown period for Lahore. HYSPLIT cluster trajectory analysis revealed the greatest impact on Lahore air quality through local emissions and regional transport from the east (agricultural burning and industry).
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Affiliation(s)
- I Karim
- University of Houston, Department of Earth and Atmospheric Science, Houston, TX, USA
| | - B Rappenglück
- University of Houston, Department of Earth and Atmospheric Science, Houston, TX, USA
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Sheoran R, Dumka UC, Hyvärinen AP, Sharma VP, Tiwari RK, Lihavainen H, Virkkula A, Hooda RK. Assessment of carbonaceous aerosols at Mukteshwar: A high-altitude (~2200 m amsl) background site in the foothills of the Central Himalayas. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 866:161334. [PMID: 36596417 DOI: 10.1016/j.scitotenv.2022.161334] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
The present study examined the equivalent black carbon (eBC) mass concentrations measured over 10.5 years (September 2005-March 2016) using a 7-wavelength Aethalometer (AE-31) at Mukteshwar, a high-altitude and regional background site in the foothills of Indian central Himalayas. The total spectral absorption coefficient (babs) was divided into three categories: black carbon (BC) and brown carbon (BrC); fossil fuels (FF) and wood/biomass burning (WB/BB); and primary and secondary sources. At the wavelength of 370 nm, a significant BrC contribution (25 %) to the total babs is identified, characterized by a pronounced seasonal variation with winter (December-January-February) maxima (31 %) and post-monsoon (October and November) minima (20 %); whereas, at 660 nm, the contribution of BrC is dramatically less (9 %). Climatologically, the estimated BCFF at 880 nm ranges from 0.25 ± 0.19 μg m-3 in July to 1.17 ± 0.80 μg m-3 in May with the annual average of 0.67 ± 0.63 μg m-3, accounting for 79 % of the BC mass. The maximum BCFF/BC fraction reaches its peak value during the monsoon (July and August, 85 %), indicating the dominance of local traffic emissions due to tourism activities. Further, the highest BCWB concentration observed during pre-monsoon (March-May) suggests the influence of local forest fires along with long-range transported aerosols from the low-altitude plains. The increased contribution of BrC (26 % at 370 nm) and WB absorption (61 % at 370 nm) to the total absorption at the shorter wavelengths suggests that wood burning is one of the major sources of BrC emissions. Secondary BrC absorption accounts for 24 % [91 %] of the total absorption [BrC absorption] at 370 nm, implying the dominance of secondary sources in BrC formation. A trend analysis for the measured BC concentration shows a statistically significant increasing trend with a slope of 0.02 μgm-3/year with a total increase of about 22 % over the study period. A back trajectory-based receptor model, potential source contribution function (PSCF), was used to identify the potential regional source region of BC. The main source regions of BC are the northwest states of India in the IGP region and the northeast Pakistan region.
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Affiliation(s)
- Rahul Sheoran
- Aryabhatta Research Institute of Observational Sciences, Nainital 263001, India; Department of Physics, D.D.U. Gorakhpur University, Gorakhpur 273009, India.
| | - U C Dumka
- Aryabhatta Research Institute of Observational Sciences, Nainital 263001, India.
| | - A P Hyvärinen
- Finnish Meteorological Institute, Erik Palménin Aukio 1, FI-00560 Helsinki, Finland
| | - V P Sharma
- The Energy and Resources Institute, New Delhi, India
| | - Rakesh K Tiwari
- Department of Physics, D.D.U. Gorakhpur University, Gorakhpur 273009, India
| | - H Lihavainen
- Finnish Meteorological Institute, Erik Palménin Aukio 1, FI-00560 Helsinki, Finland; Svalbard Integrated Arctic Earth Observing System, 156, 9171 Longyearbyen, Norway
| | - A Virkkula
- Finnish Meteorological Institute, Erik Palménin Aukio 1, FI-00560 Helsinki, Finland
| | - Rakesh K Hooda
- Finnish Meteorological Institute, Erik Palménin Aukio 1, FI-00560 Helsinki, Finland.
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Kant R, Trivedi A, Ghadai B, Kumar V, Mallik C. Interpreting the COVID effect on atmospheric constituents over the Indian region during the lockdown: chemistry, meteorology, and seasonality. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:274. [PMID: 35286487 PMCID: PMC8918593 DOI: 10.1007/s10661-022-09932-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 03/05/2022] [Indexed: 06/14/2023]
Abstract
Most of the published articles which document changes in atmospheric compositions during the various lockdown and unlock phases of COVID-19 pandemic have made a direct comparison to a reference point (which may be 1 year apart) for attribution of the COVID-mediated lockdown impact on atmospheric composition. In the present study, we offer a better attribution of the lockdown impacts by also considering the effect of meteorology and seasonality. We decrease the temporal distance between the impacted and reference points by considering the difference of adjacent periods first and then comparing the impacted point to the mean of several reference points in the previous years. Additionally, we conduct a multi-station analysis to get a holistic effect of the different climatic and emission regimes. In several places in eastern and coastal India, the seasonally induced changes already pointed to a decrease in PM concentrations based on the previous year data; hence, the actual decrease due to lockdown would be much less than that observed just on the basis of difference of concentrations between subsequent periods. In contrast, northern Indian stations would normally show an increase in PM concentration at the time of the year when lockdown was effected; hence, actual lockdown-induced change would be in surplus of the observed change. The impact of wind-borne transport of pollutants to the study sites dominates over the dilution effects. Box model simulations point to a VOC-sensitive composition.
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Affiliation(s)
- Rahul Kant
- Department of Atmospheric Science, Central University of Rajasthan, Ajmer, 305801, India
| | - Avani Trivedi
- Department of Atmospheric Science, Central University of Rajasthan, Ajmer, 305801, India
| | - Bibhutimaya Ghadai
- Department of Atmospheric Science, Central University of Rajasthan, Ajmer, 305801, India
| | - Vinod Kumar
- Max Planck Institute for Chemistry, Hahn-Meitner-Weg 1, 55128, Mainz, Germany
| | - Chinmay Mallik
- Department of Atmospheric Science, Central University of Rajasthan, Ajmer, 305801, India.
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Chaudhury AS, Nikhil V, Gokhale S. Black carbon in different climatic seasons of the Brahmaputra River Valley of Northeast India – Field measurements at two different heights and analysis. ATMOSPHERIC POLLUTION RESEARCH 2022; 13:101327. [DOI: 10.1016/j.apr.2022.101327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
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Can Forest Fires Be an Important Factor in the Reduction in Solar Power Production in India? REMOTE SENSING 2022. [DOI: 10.3390/rs14030549] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The wildfires over the central Indian Himalayan region have attracted the significant attention of environmental scientists. Despite their major and disastrous effects on the environment and air quality, studies on the forest fires’ impacts from a renewable energy point of view are lacking for this region. Therefore, for the first time, we examine the impact of massive forest fires on the reduction in solar energy production over the Indian subcontinent via remote sensing techniques. For this purpose, we used data from the Moderate Resolution Imaging Spectroradiometer (MODIS), the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIPSO), the Satellite Application Facility on support to Nowcasting/Very Short-Range Forecasting Meteosat Second Generation (SAFNWC/MSG) in conjunction with radiative transfer model (RTM) simulation, in addition to 1-day aerosol forecasts from the Copernicus Atmosphere Monitoring Service (CAMS). The energy production during the first quarter of 2021 was found to reach 650 kWh/m2 and the revenue generated was about INR (Indian rupee) 79.5 million. During the study period, the total attenuation due to aerosols and clouds was estimated to be 116 and 63 kWh/m2 for global and beam horizontal irradiance (GHI and BHI), respectively. The financial loss due to the presence of aerosols was found to be INR 8 million, with the corresponding loss due to clouds reaching INR 14 million for the total Indian solar plant’s capacity potential (40 GW). This analysis of daily energy and financial losses can help the grid operators in planning and scheduling power generation and supply during the period of fires. The findings of the present study will drastically increase the awareness among the decision makers in India about the indirect effects of forest fires on renewable energy production, and help promote the reduction in carbon emissions and greenhouse gases in the air, along with the increase in mitigation processes and policies.
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Ojha N, Girach I, Sharma K, Sharma A, Singh N, Gunthe SS. Exploring the potential of machine learning for simulations of urban ozone variability. Sci Rep 2021; 11:22513. [PMID: 34795336 PMCID: PMC8602617 DOI: 10.1038/s41598-021-01824-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 11/01/2021] [Indexed: 11/17/2022] Open
Abstract
Machine learning (ML) has emerged as a powerful technique in the Earth system science, nevertheless, its potential to model complex atmospheric chemistry remains largely unexplored. Here, we applied ML to simulate the variability in urban ozone (O3) over Doon valley of the Himalaya. The ML model, trained with past variations in O3 and meteorological conditions, successfully reproduced the independent O3 data (r2 ~ 0.7). Model performance is found to be similar when the variation in major precursors (CO and NOx) were included in the model, instead of the meteorology. Further the inclusion of both precursors and meteorology improved the performance significantly (r2 = 0.86) and the model could also capture the outliers, which are crucial for air quality assessments. We suggest that in absence of high-resolution measurements, ML modeling has profound implications for unraveling the feedback between pollution and meteorology in the fragile Himalayan ecosystem.
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Affiliation(s)
| | - Imran Girach
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, India.
| | - Kiran Sharma
- Graphic Era (Deemed to be University), Dehradun, India
| | - Amit Sharma
- Department of Civil and Infrastructure Engineering, Indian Institute of Technology Jodhpur, Jodhpur, India
| | - Narendra Singh
- Aryabhatta Research Institute of Observational Sciences, Nainital, India
| | - Sachin S Gunthe
- EWRE Division, Department of Civil Engineering, Indian Institute of Technology Madras, Chennai, India.,Laboratory for Atmospheric and Climate Sciences, Indian Institute of Technology Madras, Chennai, India
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Impacts of Aerosol Loading in the Hindu Kush Himalayan Region Based on MERRA-2 Reanalysis Data. ATMOSPHERE 2021. [DOI: 10.3390/atmos12101290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The impacts of climate change have severely affected geosphere, biosphere and cryosphere ecosystems in the Hindu Kush Himalayan (HKH) region. The impact has been accelerating further during the last few decades due to rapid increase in anthropogenic activities such as modernization, industrialization and urbanization, along with energy demands. In view of this, the present work attempts to examine aerosol optical depth (AOD) over the HKH region using the long-term homogeneous MERRA-2 reanalysis data from January, 1980 to December, 2020. The AOD trends are examined statistically with student’s t-test (t). Due to a vast landmass, fragile topography and harsh climatic conditions, we categorized the HKH region into three sub-regions, namely, the northwestern and Karakoram (HKH1), the Central (HKH2) and the southeastern Himalaya and Tibetan Plateau (HKH3). Among the sub-regions, the significant enhancement of AOD is observed at several potential sites in the HKH2 region, namely, Pokhara, Nainital, Shimla and Dehradun by 55.75 × 10−4 ± 3.76 × 10−4, 53.15 × 10−4 ± 3.94 × 10−4, 51.53 × 10−4 ± 4.99 × 10−4 and 39.16 × 10−4 ± 4.08 × 10−4 AOD year−1 (550 nm), respectively, with correlation coefficients (Rs) of 0.86 to 0.93. However, at a sub-regional scale, HKH1, HKH2 and HKH3 exhibit 23.33 × 10−4 ± 2.28 × 10−4, 32.20 × 10−4 ± 2.58 × 10−4 and 9.48 × 10−4 ± 1.21 × 10−4 AOD year−1, respectively. The estimated trends are statistically significant (t > 7.0) with R from 0.81 to 0.91. Seasonally, the present study also shows strong positive AOD trends at several potential sites located in the HKH2 region, such as Pokhara, Nainital, Shimla and Dehradun, with minimum 19.81 × 10−4 ± 3.38 × 10−4 to maximum 72.95 × 10−4 ± 4.89 × 10−4 AOD year−1 with statistical significance. In addition, there are also increasing AOD trends at all the high-altitude background sites in all seasons.
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Chemical Composition and Source Apportionment of Total Suspended Particulate in the Central Himalayan Region. ATMOSPHERE 2021. [DOI: 10.3390/atmos12091228] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The present study analyzes data from total suspended particulate (TSP) samples collected during 3 years (2005–2008) at Nainital, central Himalayas, India and analyzed for carbonaceous aerosols (organic carbon (OC) and elemental carbon (EC)) and inorganic species, focusing on the assessment of primary and secondary organic carbon contributions (POC, SOC, respectively) and on source apportionment by positive matrix factorization (PMF). An average TSP concentration of 69.6 ± 51.8 µg m−3 was found, exhibiting a pre-monsoon (March–May) maximum (92.9 ± 48.5 µg m−3) due to dust transport and forest fires and a monsoon (June–August) minimum due to atmospheric washout, while carbonaceous aerosols and inorganic species expressed a similar seasonality. The mean OC/EC ratio (8.0 ± 3.3) and the good correlations between OC, EC, and nss-K+ suggested that biomass burning (BB) was one of the major contributing factors to aerosols in Nainital. Using the EC tracer method, along with several approaches for the determination of the (OC/EC)pri ratio, the estimated SOC component accounted for ~25% (19.3–29.7%). Furthermore, TSP source apportionment via PMF allowed for a better understanding of the aerosol sources in the Central Himalayan region. The key aerosol sources over Nainital were BB (27%), secondary sulfate (20%), secondary nitrate (9%), mineral dust (34%), and long-range transported mixed marine aerosol (10%). The potential source contribution function (PSCF) and concentration weighted trajectory (CWT) analyses were also used to identify the probable regional source areas of resolved aerosol sources. The main source regions for aerosols in Nainital were the plains in northwest India and Pakistan, polluted cities like Delhi, the Thar Desert, and the Arabian Sea area. The outcomes of the present study are expected to elucidate the atmospheric chemistry, emission source origins, and transport pathways of aerosols over the central Himalayan region.
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Xiang Y, Zhang T, Liu J, Wan X, Loewen M, Chen X, Kang S, Fu Y, Lv L, Liu W, Cong Z. Vertical profile of aerosols in the Himalayas revealed by lidar: New insights into their seasonal/diurnal patterns, sources, and transport. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 285:117686. [PMID: 34380235 DOI: 10.1016/j.envpol.2021.117686] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 06/26/2021] [Accepted: 06/28/2021] [Indexed: 06/13/2023]
Abstract
Atmospheric aerosols play a crucial role in climate change, especially in the Himalayas and Tibetan Plateau. Here, we present the seasonal and diurnal characteristics of aerosol vertical profiles measured using a Mie lidar, along with surface black carbon (BC) measurements, at Mt. Qomolangma (QOMS), in the central Himalayas, in 2018-2019. Lidar-retrieved profiles of aerosols showed a distinct seasonal pattern of aerosol loading (aerosol extinction coefficient, AEC), with a maximum in the pre-monsoon (19.8 ± 22.7 Mm-1 of AEC) and minimum in the summer monsoon (7.0 ± 11.2 Mm-1 of AEC) seasons. The diurnal variation characteristics of AEC and BC were quite different in the non-monsoon seasons with enriched aerosols being maintained from 00:00 to 10:00 in the pre-monsoon season. The major aerosol types at QOMS were identified as background, pollution, and dust aerosols, especially during the pre-monsoon season. The occurrence of pollution events influenced the vertical distribution, seasonal/diurnal patterns, and types of aerosols. Source contribution of BC based on the weather research and forecasting chemical model showed that approximately 64.2% ± 17.0% of BC at the QOMS originated from India and Nepal in South Asia during the non-monsoon seasons, whereas approximately 47.7% was from local emission sources in monsoon season. In particular, the high abundance of BC at the QOMS in the pre-monsoon season was attributed to biomass burning, whereas anthropogenic emissions were the likely sources during the other seasons. The maximum aerosol concentration appeared in the near-surface layer (approximately 4.3 km ASL), and high concentrations of transported aerosols were mainly found at 4.98, 4.58, 4.74, and 4.88 km ASL in the pre-monsoon, monsoon, post-monsoon, and winter seasons, respectively. The investigation of the vertical profiles of aerosols at the QOMS can help verify the representation of aerosols in the air quality model and satellite products and regulate the anthropogenic disturbance over the Tibetan Plateau.
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Affiliation(s)
- Yan Xiang
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, China
| | - Tianshu Zhang
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, China; Key Laboratory of Environment Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031, China
| | - Jianguo Liu
- Key Laboratory of Environment Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031, China
| | - Xin Wan
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China
| | | | - Xintong Chen
- University of Chinese Academy of Sciences, Beijing, 100049, China; State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Shichang Kang
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China
| | - Yibin Fu
- Key Laboratory of Environment Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031, China
| | - Lihui Lv
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, China
| | - Wenqing Liu
- Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, China; Key Laboratory of Environment Optics and Technology, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei, 230031, China
| | - Zhiyuan Cong
- State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment (TPESRE), Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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13
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Arunkumar M, Dhanakumar S. Influence of meteorology, mobility, air mass transport and biomass burning on PM 2.5 of three north Indian cities: phase-wise analysis of the COVID-19 lockdown. ENVIRONMENTAL MONITORING AND ASSESSMENT 2021; 193:618. [PMID: 34476627 PMCID: PMC8412385 DOI: 10.1007/s10661-021-09400-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Recent studies concluded that air quality has improved due to the enforcement of lockdown in the wake of COVID-19. However, they mostly concentrated on the changes during the lockdown period, and the studies considering the consequences of de-escalation of lockdown are inadequate. Therefore, we investigated the changes in fine particulate matter (PM2.5) during the pre-lockdown, strict lockdown, unlocking, and post-lockdown scenarios. In addition, we assessed the influence of meteorology, mobility, air mass transport, and biomass burning on PM2.5 using Google's mobility data, back trajectory model, and satellite-based fire incident data. Average PM2.5 concentrations in Ghaziabad, Noida, and Faridabad decreased by 60.70%, 63.27%, and 60.40%, respectively, during the lockdown. When compared with the preceding year (2019), the reductions during the shutdown period (25 March-31 May) were within the range of 36.34-44.55%. However, considering the entire year, this reduction in PM2.5 is momentary, and a steady increase in traffic density and industrial operations within cities during post-lockdown reflects a potent recovery of aerosol level, during which the average mass of PM2.5 three- to four-folds higher than the lockdown period. Back trajectories and fire activity results showed that biomass burning in the nearby states (Haryana and Punjab) influence aerosol load. We conclude that a partial lockdown in the event of a sudden surge in pollution would be a beneficial approach. However, reducing fossil fuel consumption and switching to more environmentally friendly energy sources, developing green transport networks, and circumventing biomass burning are efficient ways to improve air quality in the long term.
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Affiliation(s)
- M. Arunkumar
- Department of Environmental Science, PSG College of Arts and Science, Tamil Nadu, Coimbatore, India 641014
| | - S. Dhanakumar
- Department of Environmental Science, PSG College of Arts and Science, Tamil Nadu, Coimbatore, India 641014
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14
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Dumka UC, Kaskaoutis DG, Mihalopoulos N, Sheoran R. Identification of key aerosol types and mixing states in the central Indian Himalayas during the GVAX campaign: the role of particle size in aerosol classification. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 761:143188. [PMID: 33143923 DOI: 10.1016/j.scitotenv.2020.143188] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/15/2020] [Accepted: 10/15/2020] [Indexed: 06/11/2023]
Abstract
Studies in aerosol properties, types and sources in the Himalayas are important for atmospheric and climatic issues due to high aerosol loading in the neighboring plains. This study uses in situ measurements of aerosol optical and microphysical properties obtained during the Ganges Valley Aerosol eXperiment (GVAX) at Nainital, India over the period June 2011-March 2012, aiming to identify key aerosol types and mixing states for two particle sizes (PM1 and PM10). Using a classification matrix based on SAE vs. AAE thresholds (scattering vs. absorption Ångström exponents, respectively), seven aerosol types are identified, which are highly dependent on particle size. An aerosol type named "large/BC mix" dominates in both PM1 (45.4%) and PM10 (46.9%) mass, characterized by aged BC mixed with other aerosols, indicating a wide range of particle sizes and mixing states. Small particles with low spectral dependence of the absorption (AAE < 1) account for 31.6% and BC-dominated aerosols for 14.8% in PM1, while in PM10, a large fraction (39%) corresponds to "large/low-absorbing" aerosols and only 3.9% is characterized as "BC-dominated". The remaining types consist of mixtures of dust and local emissions from biofuel burning and display very small fractions. The main optical properties e.g. spectral scattering, absorption, single scattering albedo, activation ratio, as well as seasonality and dependence on wind speed and direction of identified types are examined, revealing a large influence of air masses originating from the Indo-Gangetic Plains. This indicates that aerosols over the central Himalayas are mostly composed by mixtures of processed and transported polluted plumes from the plains. This is the first study that identifies key aerosol populations in the central Indian Himalayas based on in situ measurements and the results are highly important for aerosol-type inventories, chemical transport models and reducing the uncertainty in aerosol radiative forcing over the third pole.
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Affiliation(s)
- U C Dumka
- Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital 263 001, India.
| | - D G Kaskaoutis
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece; Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 71003 Crete, Greece.
| | - N Mihalopoulos
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece; Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, 71003 Crete, Greece
| | - Rahul Sheoran
- Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital 263 001, India
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15
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Srivastava P, Naja M. Characteristics of carbonaceous aerosols derived from long-term high-resolution measurements at a high-altitude site in the central Himalayas: radiative forcing estimates and role of meteorology and biomass burning. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:14654-14670. [PMID: 33219503 DOI: 10.1007/s11356-020-11579-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 11/06/2020] [Indexed: 06/11/2023]
Abstract
Simultaneous observations (2014-2017) of organic carbon (OC) and elemental carbon (EC) are made over a high-altitude site (Nainital, 29.4°N, 79.5°E, 1958 m a.m.s.l) in the central Himalayas, and the role of long-range transport, meteorology and biomass burning is studied. There are only a few online and simultaneous observations of OC and EC over South Asia and none in the high-altitude Himalayan region. This work presents the first diurnal variations with a unimodal pattern in both OC and EC at the Himalayan site. Such a diurnal pattern is in contrast with the bimodal pattern observed at any continental polluted site. Clear seasonal variations in OC and EC were seen with a primary maximum during spring and a secondary maximum in autumn/winter. OC and EC concentrations are observed to be as high as 65.8 μg/m3 and 12 μg/m3, in May, respectively. Concentration weighted trajectory (CWT)-assisted analysis shows that the biomass burning in northern India is one of the major sources for the springtime maximum even at this high-altitude site. The coinciding rise in OC/EC ratio from 4.6 to 7.9, along with fire events, further convinces that the enhancement in the concentrations is due to the biomass burning at distant regions and long-range transport of air masses influencing this high-altitude site. A poor covariation between OC-EC and the boundary-layer height during autumn and winter suggests that secondary maxima in OC and EC are most likely due to local sources, e.g. household burning for heating during this cold period when the temperature drops sharply after October and remains low until February. The higher temporal resolution of online measurements reveals that swiftly varying meteorological parameters change the OC-EC concentrations at diurnal scales. Back-air trajectory-assisted analysis of residence time and its relationship with OC and EC confirms the increase in their concentration in slow-moving air masses. The observed diurnal variations of EC are utilized to estimate the radiative forcing and shown that the atmospheric radiative forcing during the afternoon is about 70% higher than the forenoon one. It is envisaged that this dataset with diurnal observations of OC and EC would be an important input for studying the radiation budget and source apportionment over this high-altitude region.
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Affiliation(s)
- Priyanka Srivastava
- Aryabhatta Research Institute for Observational Sciences (ARIES), Manora Peak, Nainital, India
- Department of Physics and Astrophysics, University of Delhi, Delhi, India
| | - Manish Naja
- Aryabhatta Research Institute for Observational Sciences (ARIES), Manora Peak, Nainital, India.
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16
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Yin S. Biomass burning spatiotemporal variations over South and Southeast Asia. ENVIRONMENT INTERNATIONAL 2020; 145:106153. [PMID: 33002702 DOI: 10.1016/j.envint.2020.106153] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 05/27/2023]
Abstract
In this study, Moderate Resolution Imaging Spectroradiometer active fire and land use products were integrated to extract and classify biomass burning (BB) data for South Asia (SA) and Southeast Asia (SEA). Several trend and geographic distribution analyses were conducted at the grid (0.25° × 0.25°) and regional scales. As the principal local form of BB, crop residue burning (CRB) in SA increased by 844 spots/yr, and the Mann-Kendall (MK) τ reached 0.61. Additionally, the CRB in Punjab-Haryana, a region a well-known for severest CRB, presented a significant declining trend. BB in mainland SEA was much more intense and was dominated by forest and shrubland fires. Forest fires in mainland SEA declined at a rate of -209 spots/yr, and shrubland fire conversely grew at a rate of 803 spots/yr, which was likely related to the dramatic land cover change induced by the local swidden agriculture. Unlike other regions, BB in equatorial SEA primarily occurred in the second half of the year (August to October), and it was extremely vulnerable to El Niño events. When the annual sea surface temperature anomalies within the Niño 3 region improved by 1 °C, the annual BB spots and fire radiative power in equatorial SEA increased by 5.18 × 104 and 2.40 × 106 MW, respectively. Although the interannual variations in equatorial SEA were dramatic, the robust Siegel's repeated median estimator still revealed that equatorial SEA BB significantly declined by -1825 spots/yr. This regional decline reflects government endeavors to curb indigenous BB. However, regions with enhanced BB still need to draw more attention, and it is imperative for the Indonesian government to take substantial measures to reduce anthropogenic fire sources during El Niño events.
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Affiliation(s)
- Shuai Yin
- Center for Global Environmental Research, National Institute for Environmental Studies, Tsukuba 3058506, Japan.
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17
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Chatterjee A, Dutta M, Ghosh A, Ghosh SK, Roy A. Relative role of black carbon and sea-salt aerosols as cloud condensation nuclei over a high altitude urban atmosphere in eastern Himalaya. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 742:140468. [PMID: 32721716 DOI: 10.1016/j.scitotenv.2020.140468] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 06/21/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
The present study is an attempt to investigate the relative role of black carbon (BC) and sea-salt aerosols on the CCN activation over a high altitude station, Darjeeling (27.1° N and 88.15° E, 2200 m asl) at eastern Himalaya. Aerosols (CN, CCN, BC and PM2.5) were measured during premonsoon and monsoon in 2017 and 2018. A unique sampling strategy and a novel methodology were adopted that enabled us to quantitatively and separately determine the contributions of local emissions (LE), valley wind transport (VWT) and long-range transport (LRT) to BC aerosols and their role in CCN activation. On the other hand, the contributions of transported sea-salt (NaCl) aerosols to CCN activation were also determined when they interact with the local anthropogenic soluble species and when they do not. CCN (0.5% super-saturation) concentrations were found to be increased when BC aerosols were more aged (~ 80 cm-3 and 218 cm-3 increase in CCN for 1 μg m-3 increase in BCLE and BCLRT with activation ratios of 0.17 and 0.55 respectively). Local anthropogenic acidic species (SO42-/H2SO4 (g) and NO3-/HNO3 (g)) interact with NaCl resulting to Cl- depletion. Cl- depletion was increased with the increase in NO3- + SO42-(45% for1 μg m-3increase in NO3- + SO42-) that in turn sharply decreased the AR of NaCl (0.04 for 1% increase in Cl- depletion). On the other hand, higher the NO3- + SO42-, higher were the CCN activation of transported BC which could be due to the soluble coating on BC. The important and interesting fact is that when transported and interacted with anthropogenic soluble species, BC aerosols (though hydrophobic) act as much better CCN than NaCl (though hydrophilic).
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Affiliation(s)
- Abhijit Chatterjee
- Environmental Sciences Section, Bose Institute, P1/12 CIT Scheme V, II-M, Kolkata, 700054, India.
| | - Monami Dutta
- Environmental Sciences Section, Bose Institute, P1/12 CIT Scheme V, II-M, Kolkata, 700054, India
| | - Abhinandan Ghosh
- Environmental Sciences Section, Bose Institute, P1/12 CIT Scheme V, II-M, Kolkata, 700054, India
| | - Sanjay K Ghosh
- Environmental Sciences Section, Bose Institute, P1/12 CIT Scheme V, II-M, Kolkata, 700054, India
| | - Arindam Roy
- Environmental Sciences Section, Bose Institute, P1/12 CIT Scheme V, II-M, Kolkata, 700054, India
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18
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Chen P, Kang S, Tripathee L, Ram K, Rupakheti M, Panday AK, Zhang Q, Guo J, Wang X, Pu T, Li C. Light absorption properties of elemental carbon (EC) and water-soluble brown carbon (WS-BrC) in the Kathmandu Valley, Nepal: A 5-year study. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 261:114239. [PMID: 32114124 DOI: 10.1016/j.envpol.2020.114239] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 11/22/2019] [Accepted: 02/18/2020] [Indexed: 05/21/2023]
Abstract
This study presents a comprehensive analysis of organic carbon (OC), elemental carbon (EC), and particularly the light absorption characteristics of EC and water-soluble brown carbon (WS-BrC) in total suspended particles in the Kathmandu Valley from April 2013 to January 2018. The mean OC, EC, and water-soluble organic carbon (WSOC) concentrations were 34.8 ± 27.1, 9.9 ± 5.8, and 17.4 ± 12.5 μg m-3, respectively. A clear seasonal variation was observed for all carbonaceous components with higher concentrations occurring during colder months and lower concentrations in the monsoon season. The relatively low OC/EC ratio (3.6 ± 2.0) indicates fossil fuel combustion as the primary source of carbonaceous components. The optical attenuation (ATN) at 632 nm was significantly connected with EC loading (ECS) below 15 μg cm-2 but ceased as ECS increased, reflecting the increased influence of the shadowing effect. The derived average mass absorption cross-section of EC (MACEC) (7.0 ± 4.2 m2 g-1) is comparable to that of freshly emitted EC particles, further attesting that EC was mainly produced from local sources with minimal atmospheric aging processes. Relatively intensive coating with organic aerosols and/or salts (e.g., sulfate, nitrate) was probably the reason for the slightly higher MACEC during the monsoon season, whereas increased biomass burning was a major factor leading to lower MACEC in other seasons. The average MACWS-BrC at 365 nm was 1.4 ± 0.3 m2 g-1 with minimal seasonal variations. In contrast to MACEC, biomass burning was the main reason for a higher MACWS-BrC in the non-monsoon season. The relative light absorption contribution of WS-BrC to EC was 9.9% over the 300-700 nm wavelength range, with a slightly higher ratio (13.6%) in the pre-monsoon season. Therefore, both EC and WS-BrC should be considered in the study of optical properties and radiative forcing of carbonaceous aerosols in this region.
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Affiliation(s)
- Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing, 100101, China.
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
| | - Kirpa Ram
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing, 100101, China; Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, 221005, India
| | | | - Arnico K Panday
- International Centre for Integrated Mountain Development, 44700, Kathmandu, Nepal
| | - Qianggong Zhang
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing, 100101, China
| | - Junming Guo
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
| | - Xiaoxiang Wang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
| | - Tao Pu
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences (CAS), Lanzhou, 730000, China
| | - Chaoliu Li
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, CAS, Beijing, 100101, China
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19
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Tyagi B, Singh J, Beig G. Seasonal progression of surface ozone and NOx concentrations over three tropical stations in North-East India. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 258:113662. [PMID: 31796313 DOI: 10.1016/j.envpol.2019.113662] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 10/15/2019] [Accepted: 11/20/2019] [Indexed: 06/10/2023]
Abstract
Monitoring of surface ozone (O3) and Nitrogen Oxides (NOx) are vital for understanding the variation and exposure impact of these trace gases over the habitat. The present study analyses the in situ observations of surface O3 and NOx for January-December 2016, for the first time over three sites of North-Eastern India (Aizwal, Gauhati and Tezpur). The sites are major cities of north-eastern India, located in the foothills of Eastern Himalaya and have no industrial impacts. We have analysed the seasonal variation of O3 and NOx and found that the site Tezpur, which is in the valley area of Eastern Himalaya, is experiencing higher values of pollutants persisting for a long time compared to the other two stations. The correlation of surface O3 with the air temperature at all three sites suggested that all the O3 may not be locally produced, but has the contribution of transported pollution reaching to stations. The study also attempts to discover the existing variability in the surface O3 and NOx over the study area by employing continuous wavelet analysis.
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Affiliation(s)
- Bhishma Tyagi
- Department of Earth and Atmospheric Sciences, National Institute of Technology Rourkela, Rourkela, 769008, Odisha, India.
| | - Jyotsna Singh
- Shanti Raj Bhawan, Paramhans Nagar, Kandwa, Varanasi, 221106, India.
| | - G Beig
- Indian Institute of Tropical Meteorology, Pune, 411008, India.
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20
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Multi-Model Evaluation of Meteorological Drivers, Air Pollutants and Quantification of Emission Sources over the Upper Brahmaputra Basin. ATMOSPHERE 2019. [DOI: 10.3390/atmos10110703] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The temporal distributions of meteorological drivers and air pollutants over Dibrugarh, a location in the upper Brahmaputra basin, are studied using observations, models and reanalysis data. The study aims to assess the performance of the Weather Research and Forecasting model coupled with chemistry (WRF-Chem), the WRF coupled with Sulfur Transport dEposition Model (WRF-STEM), and Copernicus Atmosphere Monitoring Service (CAMS) model over Dibrugarh for the first time. The meteorological variables and air pollutants viz., black carbon(BC), carbon monoxide(CO), sulphur dioxide(SO2), Ozone(O3), and oxides of Nitrogen(NOx) obtained from WRF-Chem, WRF-STEM and CAMS are evaluated with observations. The source region tagged CO simulated by WRF-STEM delineate the regional contribution of CO. The principal source region of anthropogenic CO over Dibrugarh is North-Eastern India with a 59% contribution followed by that from China (17%), Indo-Gangetic Plains (14%), Bangladesh (6%), other parts of India (3%) and other regions (1%). Further, the BC-CO regression analysis is used to delineate the local emission sources. The BC-CO correlations estimated from models (0.99 for WRF-Chem, 0.96 for WRF-STEM, 0.89 for CAMS), and reanalysis (0.8 for Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA2) are maximum in pre-monsoon whereas surface observations show highest correlations (0.81) in winter. In pre-monsoon season, 90% of the modeled CO is due to biomass burning over Dibrugarh.
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21
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Ravindra K, Singh T, Mor S, Singh V, Mandal TK, Bhatti MS, Gahlawat SK, Dhankhar R, Mor S, Beig G. Real-time monitoring of air pollutants in seven cities of North India during crop residue burning and their relationship with meteorology and transboundary movement of air. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 690:717-729. [PMID: 31301511 DOI: 10.1016/j.scitotenv.2019.06.216] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/05/2019] [Accepted: 06/14/2019] [Indexed: 05/06/2023]
Abstract
Air pollutants emissions due to the burning of crop residues could adversely affect human health, environment, and climate. Hence, a multicity campaign was conducted during crop residue burning period in Indo Gangetic Plains (IGP) to study the impact on ambient air quality. Seventeen air pollutants along with five meteorological parameters, were measured using state of the art continuous air quality monitors. The average concentration of PM10, PM2.5, and PM1 during the whole campaign were 196.7±30.6, 148.2±20, and 51.2±8.9 μgm-3 and daily average concentration were found several times higher than national ambient air quality standards for 24h. Amritsar had the highest average concentration of PM2.5 (178.4±83.8 μgm-3) followed by Rohtak and Sonipat (158.4±79.8, 156.5±105.3μgm-3), whereas Chandigarh recorded the lowest concentration (112.3±6.9μgm-3). The concentration of gaseous pollutants NO, NO2, NOx, and SO2 were also observed highest at Amritsar location, i.e., 6.6±2.6ppb, 6.2±0.7ppb, 12.7±3.0ppb, and 7.5±3.3ppb respectively. The highest average O3 and CO were 22.5±19.3ppb and 1.5±1.2ppm during the campaign. The level of gaseous pollutants and Volatile organic compounds (VOCs) found to be elevated during the campaign, which can play an important role in the formation of secondary air pollutants. The correlation of meteorology and air pollutants was also studied, and O3 shows a significant relation with temperature and UV (R=0.87 and 0.74) whereas VOCs shows a significant correlation with temperature (R=-0.21 to -0.47). Air quality data was also analyzed to identify sources of emissions using principal component analysis, and it identifies biomass burning and vehicular activities as major sources of air pollution.
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Affiliation(s)
- Khaiwal Ravindra
- Department of Community Medicine and School of Public Health, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh 160012, India.
| | - Tanbir Singh
- Department of Environment Studies, Panjab University, Chandigarh 160014, India
| | - Sahil Mor
- Department of Environmental Science & Engineering, Guru Jambheshwar University of Science, Hisar, India
| | - Vikas Singh
- National Atmospheric Research Laboratory, Gadanki 517502, India
| | - Tuhin Kumar Mandal
- Radio and Atmospheric Sciences Division, National Physical Laboratory, New Delhi 110012, India
| | - Manpreet Singh Bhatti
- Department of Botanical & Environmental Sciences, Guru Nanak Dev University, Amritsar 143005, India
| | | | - Rajesh Dhankhar
- Department of Environment Science, Maharshi Dayanand University, Rohtak, India
| | - Suman Mor
- Department of Environment Studies, Panjab University, Chandigarh 160014, India.
| | - Gufran Beig
- Indian Institute of Tropical Meteorology, Pashan, Pune, India.
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Ojha N, Girach I, Sharma K, Nair P, Singh J, Sharma N, Singh N, Flemming J, Inness A, Subrahmanyam KV. Surface ozone in the Doon Valley of the Himalayan foothills during spring. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:19155-19170. [PMID: 31020519 DOI: 10.1007/s11356-019-05085-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 04/04/2019] [Indexed: 06/09/2023]
Abstract
Elevated ozone (O3) pollution is observed every spring over the Northern Indian region including the Himalayan foothills, with a maximum typically in the month of May. However, studies investigating influences of photochemistry and dynamics in the valleys of Central Himalaya are limited. Here, in situ surface O3 observations conducted at Dehradun (77.99° E, 30.27° N, 600 m above mean sea level) in the Doon Valley during April-July 2018 are presented. These O3 observations reveal the prevalence of an urban environment over Dehradun with enhanced levels during noontime (66.4 ppbv ± 11.0 ppbv in May) and lower levels during night (26.7 ppbv ± 11.5 ppbv). Morning time O3 enhancement rate at Dehradun (7.5 ppbv h-1) is found to be comparable to that at Bode (7.3 ppbv h-1) in another valley of Himalayan foothills (Kathmandu), indicating stronger anthropogenic emissions in the Doon Valley as well. Daily average O3 at Dehradun varied in the range of 13.7-71.3 ppbv with hourly values reaching up to 103.1 ppbv during the study period. Besides the in situ photochemical O3 production, the entrainment of O3-rich air through boundary layer dynamics also contributes in noontime O3 enhancement in the Doon Valley. Monthly average O3 at Dehradun (49.3 ppbv ± 19.9 ppbv) is observed to be significantly higher than that over urban sites in Northern India (35-41 ppbv) and Bode (38.5 ppbv) in the Kathmandu Valley during May. O3 photochemical buildup, estimated to be 30.3 ppbv and 39.7 ppbv during April and May, respectively, is significantly lower in June (21.2 ppbv). Copernicus Atmosphere Monitoring Service (CAMS) model simulations successfully reproduce the observed variability in noontime O3 at Dehradun (r = 0.86); however, absolute O3 levels were typically overestimated. The positive relationship between CAMS O3 and CO (r = 0.65) together with an O3/CO slope of 0.16 is attributed to the influences of biomass burning besides anthropogenic emissions on observed O3 variations in the Doon Valley. O3 observations show an enhancement by 35-56% at Dehradun during a high-fire activity period in May 2018 as compared to a low-fire activity period over the Northern Indian region in agreement with the enhancement found in CAMS O3 fields (10-65%) over the region in the vicinity of Dehradun.
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Affiliation(s)
- Narendra Ojha
- Space and Atmospheric Sciences Division, Physical Research Laboratory, Ahmedabad, India.
| | - Imran Girach
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, India.
| | - Kiran Sharma
- Graphic Era (Deemed to be University), Dehradun, India
| | - Prabha Nair
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, India
| | - Jaydeep Singh
- Aryabhatta Research Institute of Observational Sciences, Nainital, India
| | - Neetu Sharma
- Graphic Era (Deemed to be University), Dehradun, India
| | - Narendra Singh
- Aryabhatta Research Institute of Observational Sciences, Nainital, India
| | | | - Antje Inness
- European Centre for Medium-Range Weather Forecasts, Reading, UK
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Sen A, Karapurkar SG, Saxena M, Shenoy DM, Chaterjee A, Choudhuri AK, Das T, Khan AH, Kuniyal JC, Pal S, Singh DP, Sharma SK, Kotnala RK, Mandal TK. Stable carbon and nitrogen isotopic composition of PM 10 over Indo-Gangetic Plains (IGP), adjoining regions and Indo-Himalayan Range (IHR) during a winter 2014 campaign. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:26279-26296. [PMID: 29978315 DOI: 10.1007/s11356-018-2567-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 06/14/2018] [Indexed: 06/08/2023]
Abstract
For source identification, a field campaign involving simultaneous sampling of particulate matter (PM10) was conducted at eight sampling sites in the Indian mainland during winter 2014. The sampling sites include Delhi (upper IGP), Lucknow (middle IGP), and Kolkata (lower IGP) in the Indo-Gangetic Plains (IGP); Mohal-Kullu and Darjeeling in the Indo-Himalayan Range (IHR). In addition, Ajmer, located upwind of the IGP in NW-India and Giridih and Bhubaneswar, in the downwind to the IGP has also been chosen. To characterize the sources of the ambient PM10, stable isotope ratios of carbon (δ13CTC) and nitrogen (δ15NTN) for the total carbon (TC) and total nitrogen (TN) fractions have been considered. Ancillary chemical parameters, such as organic carbon (OC), elemental carbon (EC), and water-soluble ionic components (WSIC) mass concentrations are also presented in this paper. There was very small variation in the daily average δ13CTC ratios (- 24.8 to - 25.9‰) among the sites. Comparison with end-member stable C isotopic signatures of major typical sources suggests that the PM10 at the sites was mainly from fossil fuel and biofuel and biomass combustion. Daily average δ15NTN ratios were not observed to vary much between sites either (8.3 to 11.0‰), and the low δ15NTN levels also indicate substantial contributions from biofuel and biomass burning of primarily C3 andC4 plant matter. Graphical abstract Scatter plot of the average (± 1 standard deviation (SD)) δ13CTC (‰) compared to δ15NTN (‰) at the sampling sites.
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Affiliation(s)
- Avirup Sen
- Environmental Sciences and Biomedical Metrology Division, CSIR-National Physical Laboratory, Dr. K S Krishnan Road, New Delhi, 110012, India
| | | | - Mohit Saxena
- Environmental Sciences and Biomedical Metrology Division, CSIR-National Physical Laboratory, Dr. K S Krishnan Road, New Delhi, 110012, India
| | - Damodar M Shenoy
- CSIR-National Institute of Oceanography, Dona Paula, Goa, 403004, India
| | - Abhijit Chaterjee
- Centre for Astroparticle Physics and Space Sciences, Bose Institute, Darjeeling, Kolkata, West Bengal, India
| | | | - Trupti Das
- CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, Odisha, India
| | - Altaf H Khan
- CSIR-Indian Institute of Toxicology Research, Lucknow, Uttar Pradesh, India
| | - Jagdish Chandra Kuniyal
- G.B. Pant National Institute of Himalayan Environment and Sustainable Development, Himachal Unit, Mohal, Kullu, Himachal Pradesh, India
| | - Srimata Pal
- Indian Statistical Institute, B.T. Road, Kolkata, West Bengal, India
| | | | - Sudhir Kumar Sharma
- Environmental Sciences and Biomedical Metrology Division, CSIR-National Physical Laboratory, Dr. K S Krishnan Road, New Delhi, 110012, India
| | - Ravindra Kumar Kotnala
- Environmental Sciences and Biomedical Metrology Division, CSIR-National Physical Laboratory, Dr. K S Krishnan Road, New Delhi, 110012, India
| | - Tuhin Kumar Mandal
- Environmental Sciences and Biomedical Metrology Division, CSIR-National Physical Laboratory, Dr. K S Krishnan Road, New Delhi, 110012, India.
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Tiwari S, Kaskaoutis D, Soni VK, Dev Attri S, Singh AK. Aerosol columnar characteristics and their heterogeneous nature over Varanasi, in the central Ganges valley. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:24726-24745. [PMID: 29923051 DOI: 10.1007/s11356-018-2502-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 06/04/2018] [Indexed: 06/08/2023]
Abstract
The Indo-Gangetic Basin (IGB) experiences one of the highest aerosol loading over the globe with pronounced inter-/intra-seasonal variability. Four-year (January 2011-December 2014) continuous MICROTOPS-II sun-photometer measurements at Varanasi, central Ganges valley, provide an opportunity to investigate the aerosol physical and optical properties and their variability. A large variation in aerosol optical depth (AOD: from 0.23 to 1.89, mean of 0.82 ± 0.31) and Ångström exponent (AE: from 0.19 to 1.44, mean of 0.96 ± 0.27) is observed, indicating a highly turbid atmospheric environment with significant heterogeneity in aerosol sources, types and optical properties. The highest seasonal means of both AOD and AE are observed in the post-monsoon (October-November) season (0.95 ± 0.31 for AOD and 1.16 ± 0.14 for AE) followed by winter (December, January, February; 0.97 ± 0.34 for AOD and 1.09 ± 0.20 for AE) and are mainly attributed to the accumulation of aerosols from urban and biomass/crop residue burning emissions within a shallow boundary layer. In contrast, during the pre-monsoon and monsoon seasons, the aerosols are mostly coming from natural origin (desert and mineral dust) mixed with pollution in several cases. The spectral dependence of AE, the aerosol "curvature" effect and other graphical techniques are used for the identification of the aerosol types and their mixing processes in the atmosphere. Furthermore, the aerosol source-apportionment assessment using the weighted potential source contribution function (WPSCF) analysis reveals the different aerosol types, emission sources and transport pathways.
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Affiliation(s)
- Shani Tiwari
- Atmospheric Research Laboratory, Department of Physics, Banaras Hindu University, Varanasi, 221005, India
- Present Address: Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan
| | - Dimitris Kaskaoutis
- Atmospheric Research Team, Institute for Environmental Research and Sustainable Development, National Observatory of Athens, 11810, Athens, Greece
| | | | - Shiv Dev Attri
- India Meteorological Department, New Delhi, 110001, India
| | - Abhay Kumar Singh
- Atmospheric Research Laboratory, Department of Physics, Banaras Hindu University, Varanasi, 221005, India.
- DST-Mahamana Centre of Excellence in Climate Change Research, B.H.U, Varanasi, 221005, India.
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Pani SK, Lin NH, Chantara S, Wang SH, Khamkaew C, Prapamontol T, Janjai S. Radiative response of biomass-burning aerosols over an urban atmosphere in northern peninsular Southeast Asia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 633:892-911. [PMID: 29602124 DOI: 10.1016/j.scitotenv.2018.03.204] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 03/17/2018] [Accepted: 03/18/2018] [Indexed: 05/24/2023]
Abstract
A large concentration of finer particulate matter (PM2.5), the primary air-quality concern in northern peninsular Southeast Asia (PSEA), is believed to be closely related to large amounts of biomass burning (BB) particularly in the dry season. In order to quantitatively estimate the contributions of BB to aerosol radiative effects, we thoroughly investigated the physical, chemical, and optical properties of BB aerosols through the integration of ground-based measurements, satellite retrievals, and modelling tools during the Seven South East Asian Studies/Biomass-burning Aerosols & Stratocumulus Environment: Lifecycles & Interactions Experiment (7-SEAS/BASELInE) campaign in 2014. Clusters were made on the basis of measured BB tracers (Levoglucosan, nss-K+, and NO3-) to classify the degree of influence from BB over an urban atmosphere, viz., Chiang Mai (18.795°N, 98.957°E, 354m.s.l.), Thailand in northern PSEA. Cluster-wise contributions of BB to PM2.5, organic carbon, and elemental carbon were found to be 54-79%, 42-79%, and 39-77%, respectively. Moreover, the cluster-wise aerosol optical index (aerosol optical depth at 500nm≈0.98-2.45), absorption (single scattering albedo ≈0.87-0.85; absorption aerosol optical depth ≈0.15-0.38 at 440nm; absorption Ångström exponent ≈1.43-1.57), and radiative impacts (atmospheric heating rate ≈1.4-3.6Kd-1) displayed consistency with the degree of BB. PM2.5 during Extreme BB (EBB) was ≈4 times higher than during Low BB (LBB), whereas this factor was ≈2.5 for the magnitude of radiative effects. Severe haze (visibility≈4km) due to substantial BB loadings (BB to PM2.5≈79%) with favorable meteorology can significantly impact the local-to-regional air quality and the, daily life of local inhabitants as well as become a respiratory health threat. Additionally, such enhancements in atmospheric heating could potentially influence the regional hydrological cycle and crop productivity over Chiang Mai in northern PSEA.
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Affiliation(s)
- Shantanu Kumar Pani
- Cloud and Aerosol Laboratory, Department of Atmospheric Sciences, National Central University, Taoyuan 32001, Taiwan
| | - Neng-Huei Lin
- Cloud and Aerosol Laboratory, Department of Atmospheric Sciences, National Central University, Taoyuan 32001, Taiwan.
| | - Somporn Chantara
- Environmental Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
| | - Sheng-Hsiang Wang
- Cloud and Aerosol Laboratory, Department of Atmospheric Sciences, National Central University, Taoyuan 32001, Taiwan
| | - Chanakarn Khamkaew
- Environmental Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Tippawan Prapamontol
- Environment and Health Research Unit, Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Serm Janjai
- Department of Physics, Faculty of Science, Silpakorn University, Nakhon Pathom 73000, Thailand
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26
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Kumari S, Verma N, Lakhani A, Tiwari S, Kandikonda MK. Tropospheric ozone enhancement during post-harvest crop-residue fires at two downwind sites of the Indo-Gangetic Plain. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:18879-18893. [PMID: 29717426 DOI: 10.1007/s11356-018-2034-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 04/13/2018] [Indexed: 06/08/2023]
Abstract
In the present study, surface ozone (O3), nitrogen oxides (NOx), and carbon monoxide (CO) levels were measured at two sites downwind of fire active region in the Indo-Gangetic Plain (IGP): Agra (27.16° N, 78.08° E) and Delhi (28.37° N, 77.12° E) to study the impact of post-harvest crop-residue fires. The study period was classified into two groups: Pre-harvest period and Post-harvest period. During the post-harvest period, an enhancement of 17.3 and 31.7 ppb in hourly averaged O3 mixing ratios was observed at Agra and Delhi, respectively, under similar meteorological conditions. The rate of change of O3 was also higher in the post-harvest period by 56.2% in Agra and 39.5% in Delhi. Relatively higher O3 episodic days were observed in the post-harvest period. Fire hotspots detected by Moderate Resolution Imaging Spectroradiometer (MODIS) along with backward air-mass trajectory analysis suggested that the enhanced O3 and CO levels at the study sites during the post-harvest period could be attributed to crop-residue burning over the North-West IGP (NW-IGP). Satellite observations of surface CO mixing ratios and tropospheric formaldehyde (HCHO) column also showed higher levels during the post-harvest period. Graphical abstract.
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Affiliation(s)
- Sonal Kumari
- Department of Chemistry, Faculty of Science, Dayalbagh Educational Institute, Dayalbagh, Agra, 282110, India
| | - Nidhi Verma
- Department of Chemistry, Faculty of Science, Dayalbagh Educational Institute, Dayalbagh, Agra, 282110, India
| | - Anita Lakhani
- Department of Chemistry, Faculty of Science, Dayalbagh Educational Institute, Dayalbagh, Agra, 282110, India
| | - Suresh Tiwari
- Indian Institute of Tropical Meteorology (Branch), Prof Ram NathVij Marg, New Delhi, 110060, India
| | - Maharaj Kumari Kandikonda
- Department of Chemistry, Faculty of Science, Dayalbagh Educational Institute, Dayalbagh, Agra, 282110, India.
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27
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Li Q, Wang N, Barbante C, Kang S, Yao P, Wan X, Barbaro E, Del Carmen Villoslada Hidalgo M, Gambaro A, Li C, Niu H, Dong Z, Wu X. Levels and spatial distributions of levoglucosan and dissolved organic carbon in snowpits over the Tibetan Plateau glaciers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 612:1340-1347. [PMID: 28898940 DOI: 10.1016/j.scitotenv.2017.08.267] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 08/21/2017] [Accepted: 08/27/2017] [Indexed: 06/07/2023]
Abstract
In this study, we collected 60 snowpit samples in nine glaciers from the northern to the southern Tibetan Plateau (TP), to study the levels and spatial distributions of levoglucosan and dissolved organic carbon (DOC). The lowest concentration of levoglucosan was found in the Yuzhufeng (YZF) glacier with a mean value of 0.24±0.08ngmL-1, while the highest concentration of levoglucosan was detected in the Gurenhekou (GRHK) glacier with a mean value of 11.72±15.61ngmL-1. However, the average DOC concentration in TP glaciers were comparable, without significant regional differences. The levoglucosan/DOC ratio ranged from 0.02 to 6.03% in the Tibetan Plateau glaciers. This ratios and the correlations between levoglucosan and DOC suggested that biomass burning products contributed only marginally to DOC levels in the TP glaciers. Moreover, the analysis of air mass backward trajectories suggested that levoglucosan and DOC in TP glaciers should be transported from the northwestern TP, internal TP, Central Asia, South and East Asia regions.
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Affiliation(s)
- Quanlian Li
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, CAS, Lanzhou 730000, China.
| | - Ninglian Wang
- Shanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, Xi'an, 710127, China; Institute of Earth Surface System and Hazards, Northwest University, Xi'an 710127, China; College of Urban and Environmental Sciences, Northwest University, Xi'an 710127, China
| | - Carlo Barbante
- Department of Environmental Sciences, Informatics and Statistics, Ca'Foscari, University of Venice, Venice, Mestre 30172, Italy; Institute for the Dynamics of Environmental Processes-CNR, Venice, Italy
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, CAS, Lanzhou 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China
| | - Ping Yao
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Xin Wan
- Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Elena Barbaro
- Department of Environmental Sciences, Informatics and Statistics, Ca'Foscari, University of Venice, Venice, Mestre 30172, Italy; Institute for the Dynamics of Environmental Processes-CNR, Venice, Italy
| | - Maria Del Carmen Villoslada Hidalgo
- Department of Environmental Sciences, Informatics and Statistics, Ca'Foscari, University of Venice, Venice, Mestre 30172, Italy; Institute for the Dynamics of Environmental Processes-CNR, Venice, Italy
| | - Andrea Gambaro
- Department of Environmental Sciences, Informatics and Statistics, Ca'Foscari, University of Venice, Venice, Mestre 30172, Italy; Institute for the Dynamics of Environmental Processes-CNR, Venice, Italy
| | - Chaoliu Li
- CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China; Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Hewen Niu
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, CAS, Lanzhou 730000, China
| | - Zhiwen Dong
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, CAS, Lanzhou 730000, China
| | - Xiaobo Wu
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, CAS, Lanzhou 730000, China
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28
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Hegde P, Kawamura K. Chemical Constituents of Carbonaceous and Nitrogen Aerosols over Thumba Region, Trivandrum, India. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2017; 73:456-473. [PMID: 28668997 DOI: 10.1007/s00244-017-0426-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 06/19/2017] [Indexed: 06/07/2023]
Abstract
Aerosol filter samples collected at a tropical coastal site Thumba over Indian region were analysed for water-soluble ions, total carbon and nitrogen, organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon/nitrogen and their sources for different seasons of the year. For the entire study period, the order of abundance of ions showed the dominance of secondary ions, such as SO42-, NO3-, and NH4+. On average, Mg2+ (56%), K+ (11%), SO42- (8.8%), and Ca2+ (8.1%) contributions were from maritime influence. There was significant chloride depletion due to enhanced levels of inorganic acids, such as SO42- and NO3-. Total carbon contributed 21% of the aerosol total suspended particulate matter in which 85% is organic carbon. Primary combustion-generated carbonaceous aerosols contributed 41% of aerosol mass for the entire study period. High average ratios of OC/EC (5.5 ± 1.8) and WSOC/OC (0.38 ± 0.11) suggest that organic aerosols are predominantly comprised of secondary species. In our samples, major fraction (89 ± 9%) was found to be inorganic nitrate in total nitrogen (TN). Good correlations (R 2 ≥ 0.82) were observed between TN with NO3- plus NH4+, indicating that nitrate and ammonium ions account for a significant portion of TN. The temporal variations in the specific carbonaceous aerosols and air mass trajectories demonstrated that several pollutants and/or their precursor compounds are likely transported from north western India and the oceanic regions.
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Affiliation(s)
- Prashant Hegde
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum, India.
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan.
| | - Kimitaka Kawamura
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
- Chubu Institute for Advanced Studies, Chubu University, Kasugai, Japan
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29
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Chen J, Li C, Ristovski Z, Milic A, Gu Y, Islam MS, Wang S, Hao J, Zhang H, He C, Guo H, Fu H, Miljevic B, Morawska L, Thai P, Lam YF, Pereira G, Ding A, Huang X, Dumka UC. A review of biomass burning: Emissions and impacts on air quality, health and climate in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 579:1000-1034. [PMID: 27908624 DOI: 10.1016/j.scitotenv.2016.11.025] [Citation(s) in RCA: 342] [Impact Index Per Article: 48.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/04/2016] [Accepted: 11/04/2016] [Indexed: 05/17/2023]
Abstract
Biomass burning (BB) is a significant air pollution source, with global, regional and local impacts on air quality, public health and climate. Worldwide an extensive range of studies has been conducted on almost all the aspects of BB, including its specific types, on quantification of emissions and on assessing its various impacts. China is one of the countries where the significance of BB has been recognized, and a lot of research efforts devoted to investigate it, however, so far no systematic reviews were conducted to synthesize the information which has been emerging. Therefore the aim of this work was to comprehensively review most of the studies published on this topic in China, including literature concerning field measurements, laboratory studies and the impacts of BB indoors and outdoors in China. In addition, this review provides insights into the role of wildfire and anthropogenic BB on air quality and health globally. Further, we attempted to provide a basis for formulation of policies and regulations by policy makers in China.
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Affiliation(s)
- Jianmin Chen
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China; Collaborative Innovation Center of Climate Change, School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China.
| | - Chunlin Li
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Zoran Ristovski
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Andelija Milic
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Yuantong Gu
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Mohammad S Islam
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Shuxiao Wang
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
| | - Jiming Hao
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
| | - Hefeng Zhang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Congrong He
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Hai Guo
- Department of Civil and Environmental Engineering, Hong Kong Polytechnic University, Hong Kong, China
| | - Hongbo Fu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Branka Miljevic
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Lidia Morawska
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia.
| | - Phong Thai
- International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - Yun Fat Lam
- School of Energy and Environment, City University of Hong Kong, Hong Kong, China
| | - Gavin Pereira
- School of Public Health, Curtin University, Perth, WA, 6000, Australia
| | - Aijun Ding
- Collaborative Innovation Center of Climate Change, School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China
| | - Xin Huang
- Collaborative Innovation Center of Climate Change, School of Atmospheric Sciences, Nanjing University, Nanjing 210023, China
| | - Umesh C Dumka
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China; Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital 263001, India
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30
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Dumka UC, Saheb SD, Kaskaoutis DG, Kant Y, Mitra D. Columnar aerosol characteristics and radiative forcing over the Doon Valley in the Shivalik range of northwestern Himalayas. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:25467-25484. [PMID: 27704378 DOI: 10.1007/s11356-016-7766-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 09/22/2016] [Indexed: 05/05/2023]
Abstract
Spectral aerosol optical depth (AOD) measurements obtained from multi-wavelength radiometer under cloudless conditions over Doon Valley, in the foothills of the western Himalayas, are analysed during the period January 2007 to December 2012. High AOD values of 0.46 ± 0.08 and 0.52 ± 0.1 at 500 nm, along with low values of Ångström exponent (0.49 ± 0.01 and 0.44 ± 0.03) during spring (March-May) and summer (June-August), respectively, suggest a flat AOD spectrum indicative of coarse-mode aerosol abundance compared with winter (December-February) and autumn (September-November), which are mostly dominated by fine aerosols from urban/industrial emissions and biomass burning. The columnar size distributions (CSD) retrieved from the King's inversion of spectral AOD exhibit bimodal size patterns during spring and autumn, while combinations of the power-law and unimodal distributions better simulate the retrieved CSDs during winter and summer. High values of extinction coefficient near the surface (∼0.8-1.0 km-1 at 532 nm) and a steep decreasing gradient above are observed via CALIPSO profiles in autumn and winter, while spring and summer exhibit elevated aerosol layers between ∼1.5 and 3.5 km due to the presence of dust. The particle depolarisation ratio shows a slight increasing trend with altitude, with higher values in spring and summer indicative of non-spherical particles of dust origin. The aerosol-climate implications are evaluated via the aerosol radiative forcing (ARF), which is estimated via the synergy of OPAC and SBDART models. On the monthly basis, the ARF values range from ∼ -30 to -90 W m-2 at the surface, while aerosols cause an overall cooling effect at the top of atmosphere (approx. -5 to -15 W m-2). The atmospheric heating via aerosol absorption results in heating rates of 1.2-1.6 K day-1 during March-June, which may contribute to changes in monsoon circulation over northern India and the Himalayas.
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Affiliation(s)
- U C Dumka
- Aryabhatta Research Institute of Observational Sciences, Manora Peak, Nainital, Uttarakhand, 263 001, India.
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai, 200 433, China.
| | - Shaik Darga Saheb
- Department of Space, Indian Institute of Remote Sensing, ISRO, Dehradun, Uttarakhand, 248 001, India
| | - D G Kaskaoutis
- Atmospheric Research Team, Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Athens, 11810, Greece
| | - Yogesh Kant
- Department of Space, Indian Institute of Remote Sensing, ISRO, Dehradun, Uttarakhand, 248 001, India
| | - D Mitra
- Department of Space, Indian Institute of Remote Sensing, ISRO, Dehradun, Uttarakhand, 248 001, India
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Tiwari S, Kumar R, Tunved P, Singh S, Panicker AS. Significant cooling effect on the surface due to soot particles over Brahmaputra River Valley region, India: An impact on regional climate. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 562:504-516. [PMID: 27107649 DOI: 10.1016/j.scitotenv.2016.03.157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 03/21/2016] [Accepted: 03/21/2016] [Indexed: 06/05/2023]
Abstract
Black carbon (BC) is an important atmospheric aerosol constituent that affects the climate by absorbing (directly) the sunlight and modifying cloud characteristics (indirectly). Here, we present first time yearlong measurements of BC and carbon monoxide (CO) from an urban location of Guwahati located in the Brahmaputra River valley (BRV) in the northeast region of India from 1st July 2013 to 30th June 2014. Daily BC concentrations varied within the range of 2.86 to 11.56μgm(-3) with an annual average of 7.17±1.89μgm(-3), while, CO varied from 0.19 to 1.20ppm with a mean value of 0.51±0.19ppm during the study period. The concentrations of BC (8.37μgm(-3)) and CO (0.67ppm) were ~39% and ~55% higher during the dry months (October to March) than the wet months (April to September) suggesting that seasonal changes in meteorology and emission sources play an important role in controlling these species. The seasonal ΔBC/ΔCO ratios were highest (lowest) in the pre-monsoon (winter) 18.1±1.4μgm(-3)ppmv(-1) (12.6±2.2μgm(-3)ppmv(-1)) which indicate the combustion of biofuel/biomass as well as direct emissions from fossil fuel during the pre-monsoon season. The annual BC emission was estimated to be 2.72Gg in and around Guwahati which is about 44% lower than the mega city 'Delhi' (4.86Gg). During the study period, the annual mean radiative forcing (RF) at the top of the atmosphere (TOA) for clear skies of BC was +9.5Wm(-2), however, the RF value at the surface (SFC) was -21.1Wm(-2) which indicates the net warming and cooling effects, respectively. The highest RF at SFC was in the month of April (-30Wm(-2)) which is coincident with the highest BC mass level. The BC atmospheric radiative forcing (ARF) was +30.16 (annual mean) Wm(-2) varying from +23.1 to +43.8Wm(-2). The annual mean atmospheric heating rate (AHR) due to the BC aerosols was 0.86Kday(-1) indicates the enhancement in radiation effect over the study region. The Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) captured the seasonal cycle of observed BC fairly well but underestimated the observed BC during the month of May-August. Model results show that BC at Guwahati is controlled mainly by anthropogenic emissions except during the pre-monsoon season when open biomass burning also makes a similar contribution.
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Affiliation(s)
- S Tiwari
- Indian Institute of Tropical Meteorology, New Delhi Branch, New Delhi 110060, India; Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm SE-10691, Sweden.
| | - R Kumar
- Research Application Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
| | - P Tunved
- Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm SE-10691, Sweden
| | - S Singh
- CSIR, Central Institute of Mining & Fuel Research, Dhanbad, Jharkhand 826001, India
| | - A S Panicker
- Indian Institute of Tropical Meteorology, Pune 411008, India
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Ningombam SS, Srivastava AK, Bagare SP, Singh RB, Kanawade VP, Dorjey N. Assessment of aerosol optical and micro-physical features retrieved from direct and diffuse solar irradiance measurements from Skyradiometer at a high altitude station at Merak: Assessment of aerosol optical features from Merak. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:16610-16619. [PMID: 26081773 DOI: 10.1007/s11356-015-4788-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 05/26/2015] [Indexed: 06/04/2023]
Abstract
Optical and micro-physical features of aerosol are reported using Skyradiometer (POM-01L, Prede, Japan) observations taken from a high-altitude station Merak, located in north-eastern Ladakh of the western trans-Himalayas region during January 2011 to December 2013. The observed daily mean aerosol optical depth (AOD, at 500 nm) at the site varied from 0.01 to 0.14. However, 75 % of the observed AOD lies below 0.05 during the study period. Seasonal peaks of AOD occurred in spring as 0.06 and minimum in winter as 0.03 which represents the aged background aerosols at the site. Yearly mean AOD at 500 nm is found to be around 0.04 and inter-annual variations of AOD is very small (nearly ±0.01). Angstrom exponent (a) varied seasonally from 0.73 in spring to 1.5 in autumn. About 30 % of the observed a lies below 0.8 which are the indicative for the presence of coarse-mode aerosols at the site. The station exhibits absorbing aerosol features which prominently occurred during spring and that may be attributed by the transported anthropogenic aerosol from Indo-Gangatic Plain (IGP). Results were well substantiated with the air mass back-trajectory analysis. Furthermore, seasonal mean of single scattering albedo (SSA at 500 nm) varied from of 0.94 to 0.98 and a general increasing trend is noticed from 400 to 870 nm wavelengths. These features are apparently regional characteristics of the site. Aerosol asymmetry factor (AS) decreases gradually from 400 to 870 nm and varied from 0.66 to 0.69 at 500 nm across the seasons. Dominance of desert-dust aerosols, associated by coarse mode, is indicated by tri-modal features of aerosol volume size distribution over the station during the entire seasons.
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Affiliation(s)
| | - A K Srivastava
- Indian Institute of Tropical Meteorology, (New Delhi Branch) Prof. Ram Nath Vij Marg, New Delhi, 110060, India
| | - S P Bagare
- Indian Institute of Astrophysics, 2nd Block Koramangala, Bangalore, 560034, India
| | - R B Singh
- Formerly with Indian Institute of Astrophysics, 2nd Block Koramangala, Bangalore, 560034, India
| | - V P Kanawade
- Department of Physical Geography and Ecosystem Science, Lund University, 223 62, Lund, Sweden
| | - Namgyal Dorjey
- Indian Astronomical Observatory (IIA) Hanle, Ladakh, India
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Bisht DS, Dumka UC, Kaskaoutis DG, Pipal AS, Srivastava AK, Soni VK, Attri SD, Sateesh M, Tiwari S. Carbonaceous aerosols and pollutants over Delhi urban environment: Temporal evolution, source apportionment and radiative forcing. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 521-522:431-45. [PMID: 25864155 DOI: 10.1016/j.scitotenv.2015.03.083] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 02/21/2015] [Accepted: 03/20/2015] [Indexed: 05/10/2023]
Abstract
Particulate matter (PM2.5) samples were collected over Delhi, India during January to December 2012 and analysed for carbonaceous aerosols and inorganic ions (SO4(2-) and NO3(-)) in order to examine variations in atmospheric chemistry, combustion sources and influence of long-range transport. The PM2.5 samples are measured (offline) via medium volume air samplers and analysed gravimetrically for carbonaceous (organic carbon, OC; elemental carbon, EC) aerosols and inorganic ions (SO4(2-) and NO3(-)). Furthermore, continuous (online) measurements of PM2.5 (via Beta-attenuation analyser), black carbon (BC) mass concentration (via Magee scientific Aethalometer) and carbon monoxide (via CO-analyser) are carried out. PM2.5 (online) range from 18.2 to 500.6μgm(-3) (annual mean of 124.6±87.9μgm(-3)) exhibiting higher night-time (129.4μgm(-3)) than daytime (103.8μgm(-3)) concentrations. The online concentrations are 38% and 28% lower than the offline during night and day, respectively. In general, larger night-time concentrations are found for the BC, OC, NO3(-)and SO4(2-), which are seasonally dependent with larger differences during late post-monsoon and winter. The high correlation (R(2)=0.74) between OC and EC along with the OC/EC of 7.09 (day time) and 4.55 (night-time), suggest significant influence of biomass-burning emissions (burning of wood and agricultural waste) as well as secondary organic aerosol formation during daytime. Concentrated weighted trajectory (CWT) analysis reveals that the potential sources for the carbonaceous aerosols and pollutants are local emissions within the urban environment and transported smoke from agricultural burning in northwest India during post-monsoon. BC radiative forcing estimates result in very high atmospheric heating rates (~1.8-2.0Kday(-1)) due to agricultural burning effects during the 2012 post-monsoon season.
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Affiliation(s)
- D S Bisht
- Indian Institute of Tropical Meteorology, New Delhi, India
| | - U C Dumka
- Aryabhatta Research Institute of Observational Sciences, Nainital, India.
| | - D G Kaskaoutis
- School of Natural Sciences, Shiv Nadar University, Tehsil Dadri, India
| | - A S Pipal
- Department of Chemistry, Savitribai Phule Pune University, Pune, India
| | - A K Srivastava
- Indian Institute of Tropical Meteorology, New Delhi, India
| | - V K Soni
- India Meteorology Department, Lodhi Road, New Delhi, India
| | - S D Attri
- India Meteorology Department, Lodhi Road, New Delhi, India
| | - M Sateesh
- India Meteorology Department, Lodhi Road, New Delhi, India
| | - S Tiwari
- Indian Institute of Tropical Meteorology, New Delhi, India
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Srivastava AK, Ram K, Singh S, Kumar S, Tiwari S. Aerosol optical properties and radiative effects over Manora Peak in the Himalayan foothills: seasonal variability and role of transported aerosols. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 502:287-295. [PMID: 25261819 DOI: 10.1016/j.scitotenv.2014.09.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 07/03/2014] [Accepted: 09/07/2014] [Indexed: 06/03/2023]
Abstract
The higher altitude regions of Himalayas and Tibetan Plateau are influenced by the dust and black carbon (BC) aerosols from the emissions and long-range transport from the adjoining areas. In this study, we present impacts of advection of polluted air masses of natural and anthropogenic emissions, on aerosol optical and radiative properties at Manora Peak (~2000 m amsl) in central Himalaya over a period of more than two years (February 2006-May 2008). We used the most updated and comprehensive data of chemical and optical properties available in one of the most climatically sensitive region, the Himalaya, to estimate atmospheric radiative forcing and heating rate. Aerosol optical depth (AOD) was found to vary from 0.04 to 0.45 with significantly higher values in summer mainly due to an increase in mineral dust and biomass burning aerosols due to transport. In contrast, single scattering albedo (SSA) varied from 0.74 to 0.88 with relatively lower values during summer, suggesting an increase in absorbing BC and mineral dust aerosols. As a result, a large positive atmospheric radiative forcing (about 28 ± 5 Wm(-2)) and high values of corresponding heating rate (0.80 ± 0.14 Kday(-1)) has been found during summer. During the entire observation period, radiative forcing at the top of the atmosphere varied from -2 to +14 Wm(-2) and from -3 to -50 Wm(-2) at the surface whereas atmospheric forcing was in the range of 3 to 65 Wm(-2) resulting in a heating rate of 0.1-1.8 Kday(-1).
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Affiliation(s)
- A K Srivastava
- Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi, India
| | - K Ram
- Institute of Environment & Sustainable Development, Banaras Hindu University, Varanasi, India
| | - Sachchidanand Singh
- Radio & Atmospheric Sciences Division, CSIR-National Physical Laboratory, New Delhi, India.
| | - Sanjeev Kumar
- Radio & Atmospheric Sciences Division, CSIR-National Physical Laboratory, New Delhi, India
| | - S Tiwari
- Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi, India
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Xu J, Zhang Q, Li X, Ge X, Xiao C, Ren J, Qin D. Dissolved organic matter and inorganic ions in a central Himalayan glacier--insights into chemical composition and atmospheric sources. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:6181-6188. [PMID: 23668686 DOI: 10.1021/es4009882] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Melting of Himalayan glaciers can be accelerated by the deposition of airborne black carbon and mineral dust as it leads to significant reductions of the surface albedo of snow and ice. Whereas South Asia has been shown a primary source region to these particles, detailed sources of these aerosol pollutants remain poorly understood. In this study, the chemical compositions of snow pit samples collected from Jima Yangzong glacier in the central Himalayas were analyzed to obtain information of atmospheric aerosols deposited from summer 2009 to spring 2010. Especially, an Aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) was used for the first time to chemically characterize the dissolved organic and inorganic matter (DOM and DIM) in snow samples. The concentrations of these species varied seasonally, with high levels observed during the winter-spring period and low levels during the summer monsoon period. On average, the dissolved substances was dominated by organics (58%) with important contributions from inorganic species, NO3(-) (12.5%), Ca(2+) (9.1%), NH4(+) (8.7%), and SO(4)(2-) (8.1%). DOM was found more oxidized with an average (± 1σ) atomic oxygen-to-carbon ratio (nO/nC) of 0.64 (± 0.14) and organic mass-to-carbon ratio (OM/OC) of 2.01 (± 0.19) during the winter-spring periods compared to the summer season (nO/nC = 0.31 ± 0.09 and OM/OC = 1.58 ± 0.12). In addition, biomass burning particles were found significantly enhanced in snow during the winter-spring periods, consistent with HYSPLIT back trajectory analysis of air mass history, which indicates prevailing atmospheric transport from northwest India and Nepal.
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Affiliation(s)
- Jianzhong Xu
- State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, CAS, Lanzhou 730000, China
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Ojha N, Naja M, Singh KP, Sarangi T, Kumar R, Lal S, Lawrence MG, Butler TM, Chandola HC. Variabilities in ozone at a semi-urban site in the Indo-Gangetic Plain region: Association with the meteorology and regional processes. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jd017716] [Citation(s) in RCA: 89] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Muntaseer Billah Ibn Azkar MA, Chatani S, Sudo K. Simulation of urban and regional air pollution in Bangladesh. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd016509] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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