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Pippal PS, Kumar R, Kumar R, Singh A. Integrating satellite and model data to explore spatial-temporal changes in aerosol optical properties and their meteorological relationships in northwest India. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 922:170835. [PMID: 38354813 DOI: 10.1016/j.scitotenv.2024.170835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/29/2024] [Accepted: 02/07/2024] [Indexed: 02/16/2024]
Abstract
This study aims to analyze the temporal and spatial distribution of Aerosol Optical Properties across Northwest India using aerosol data from MODIS (Moderate Resolution Imaging Spectroradiometer) and OMI (Ozone Monitoring Instrument) sensors from 2003 to 2022. Therefore, this study investigated the decadal, interannual, and seasonal changes in aerosol optical properties, vegetation index, and meteorological parameters in the northwest Indian region (8 boxes). Using GIOVANNI (Goddard Earth Sciences Data and Information Services Center (GES DISC) Online Visualization and Analysis Infrastructure), we retrieved daily and monthly Aqua and Terra MODIS products of aerosol optical depth (AOD), Angstrom exponent (AE), normalized difference vegetation index (NDVI), and OMI aerosol index (AI) to examine the spatiotemporal variations by using statistical approaches. The results demonstrated that the decadal averages of aerosol properties showed values of AOD 0.35 (Aqua) and 0.34 (Terra) and AE 1.20 (Aqua) and 1.10 (Terra) with the highest levels during the post-monsoon. Notably, the mean interannual concentrations of AOD and NDVI consistently surpass 0.3, and AE and AI exceed 1 in most locations, underscoring the persistence of high aerosol loading. Also, the study revealed a negative decadal change in AOD of about -8.24 %, while AE, AI, and NDVI showed positive decadal changes of about 9.24 %, 15.09 %, and 12.67 %, respectively. In addition, aerosol optical properties and local meteorology strongly correlated (-0.8 to +0.8). Principal Component Analysis (PCA) identifies meteorological parameters as significant drivers, with the first three components explaining over 70 % of the variation in aerosol optical properties. The NOAA HYSPLIT trajectory model suggests that the long-distance dust transport from the Arabian Peninsula frequently penetrates Gujarat province and then to northwest India. The results contributed to air quality management strategies and provided valuable insights into regional climate and air quality with the influence of meteorology.
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Affiliation(s)
- Prity S Pippal
- Department of Environmental Science, School of Earth Sciences, Central University of Rajasthan, Ajmer, Rajasthan, India
| | - Rajesh Kumar
- Department of Environmental Science, School of Earth Sciences, Central University of Rajasthan, Ajmer, Rajasthan, India.
| | - Ramesh Kumar
- Department of Environmental Science, School of Earth Sciences, Central University of Rajasthan, Ajmer, Rajasthan, India; Department of Environmental Science, Parul Institute of Applied Sciences, Parul University, Vadodara, Gujarat, India
| | - Atar Singh
- Centre for Cryosphere and Climate Change Studies, National Institute of Hydrology, Roorkee, India
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Wang L, Ju T, Li B, Xia X, Huang C, Lv Z, Gu Z. Analysis of human health effects under ozone exposure in the oasis area of Hetao Plain. ENVIRONMENTAL MONITORING AND ASSESSMENT 2024; 196:426. [PMID: 38573396 DOI: 10.1007/s10661-024-12579-1] [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: 11/21/2023] [Accepted: 03/23/2024] [Indexed: 04/05/2024]
Abstract
This article, based on OMI data products, utilizes spatial distribution, ozone-sensitive control areas, Pearson correlation methods, and the Ben-MAP model to study the changes in ozone column concentration from 2018 to 2022, along with the influencing factors and the health of populations exposed to ozone. The findings suggest a spatial variation in the ozone column concentration within the study area, with an increasing trend observed from west to east and from south to north. Over time, the ozone column concentration exhibits an initial increase followed by a subsequent decrease, with the peak concentration observed in 2019 at 37.45 DU and the nadir recorded in 2022 at 33.10 DU. The monthly mean distribution exhibits an inverted V-shaped pattern during the warm season from April to September, with a peak in July (46.71 DU) and a trough in April (35.29 DU). The Hetao Plain Oasis area is primarily a NOx control area in sensitive control areas. The concentrations of O3 and precursor HCHO exhibited significant positive correlations with vegetation index and air temperature, while showing significant negative correlations with wind speed and air pressure. The precursor NO2, in contrast, exhibited a significant negative correlation with both the vegetation index and relative humidity. Based on the ground-based monitoring sites and analysis of human health benefits, the study area witnessed 1944.45 deaths attributed to warm season O3 exposure in 2018, with a subsequent reduction in premature deaths by 149.7, 588.2, and 231.75 for the years 2019 to 2021 respectively when compared to the baseline year. In 2021, the observed decrease in warm-season O3 concentration within that region compared to 2018 resulted in a significant reduction, leading to the prevention of 126 premature deaths.
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Affiliation(s)
- Lanzhi Wang
- College of Geography and Environmental Sciences, Northwest Normal University, Lanzhou, 730000, China
- The Key Laboratory of Resource Environment and Sustainable Development of Oasis, Jiayuguan, 730000, Gansu Province, China
- Gansu Province Environmental Science and Engineering Demonstration Laboratory, Lanzhou, 202018, China
| | - Tianzhen Ju
- College of Geography and Environmental Sciences, Northwest Normal University, Lanzhou, 730000, China.
- The Key Laboratory of Resource Environment and Sustainable Development of Oasis, Jiayuguan, 730000, Gansu Province, China.
- Gansu Province Environmental Science and Engineering Demonstration Laboratory, Lanzhou, 202018, China.
| | - Bingnan Li
- Faculty of Atmospheric Remote Sensing, Shaanxi Normal University, Xi'an, 710062, China
| | - Xuhui Xia
- College of Geography and Environmental Sciences, Northwest Normal University, Lanzhou, 730000, China
- The Key Laboratory of Resource Environment and Sustainable Development of Oasis, Jiayuguan, 730000, Gansu Province, China
- Gansu Province Environmental Science and Engineering Demonstration Laboratory, Lanzhou, 202018, China
| | - Cheng Huang
- College of Geography and Environmental Sciences, Northwest Normal University, Lanzhou, 730000, China
- The Key Laboratory of Resource Environment and Sustainable Development of Oasis, Jiayuguan, 730000, Gansu Province, China
- Gansu Province Environmental Science and Engineering Demonstration Laboratory, Lanzhou, 202018, China
| | - Zhichao Lv
- College of Geography and Environmental Sciences, Northwest Normal University, Lanzhou, 730000, China
- The Key Laboratory of Resource Environment and Sustainable Development of Oasis, Jiayuguan, 730000, Gansu Province, China
- Gansu Province Environmental Science and Engineering Demonstration Laboratory, Lanzhou, 202018, China
| | - Zhenrong Gu
- College of Geography and Environmental Sciences, Northwest Normal University, Lanzhou, 730000, China
- The Key Laboratory of Resource Environment and Sustainable Development of Oasis, Jiayuguan, 730000, Gansu Province, China
- Gansu Province Environmental Science and Engineering Demonstration Laboratory, Lanzhou, 202018, China
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Rupakheti D, Aculinin A, Rupakheti M, Dahal S, Rai M, Yin X, Yu X, Abdullaev SF, Hu J. Insights on aerosol properties using two decades-long ground-based remote sensing datasets in Moldova, Eastern Europe. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 337:122535. [PMID: 37696329 DOI: 10.1016/j.envpol.2023.122535] [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: 06/09/2023] [Revised: 08/17/2023] [Accepted: 09/08/2023] [Indexed: 09/13/2023]
Abstract
Aerosol optical properties were studied over Chisinau in Moldova, one of the longest running AERONET sites in Eastern Europe. During two decades (September 1999-November 2018), the mean aerosol optical depth (AOD) and Angstrom exponent (AE) were observed as 0.21 ± 0.13 and 1.49 ± 0.29, respectively. The highest AOD (0.24 ± 0.13) and AE (1.60 ± 0.26) were observed during the summer. More than half (∼55%) of the share was occupied by clean continental aerosols with seasonal order of winter (74.8%) > autumn (62%) > spring (48.9%) > summer (44.8%) followed by mixed aerosols with a respective contribution of 30.7% (summer), 28.4% (spring), 22.5 (autumn) and 16.4% (winter). A clear dominance of volume size distribution in the fine mode indicated the stronger influence of anthropogenic activities resulting in fine aerosol load in the atmosphere. The peak in the fine mode was centered at 0.15 μm, whereas that of the coarse mode was centered either at 3.86 μm (summer and autumn) or 5.06 μm (spring and winter). 'Extreme' aerosol events were observed during 21 days with a mean AOD (AE) of 0.99 ± 0.32 (1.43 ± 0.43), whereas 'strong' events were observed during 123 days with a mean AOD (AE) of 0.57 ± 0.07 (1.44 ± 0.40), mainly influenced by anthropogenic aerosols (during 19 and 101 days of each event type) from urban/industrial and biomass burning indicated by high AE and fine mode fraction. During the whole period (excluding events days), the fine and coarse mode peaks were observed at the radius of 0.15 and 5.06 μm, which in the case of extreme (strong) events were at 0.19 (0.15) and 3.86 (2.24) μm respectively. The fine mode volume concentration was 4.78 and 3.32 times higher, whereas the coarse mode volume concentration was higher by a factor of 1.98 and 2.27 during extreme and strong events compared to the whole period.
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Affiliation(s)
- Dipesh Rupakheti
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China; Institute of Fundamental Research and Studies (InFeRS), Kathmandu 44600, Nepal
| | - Alexandr Aculinin
- Institute of Applied Physics (IAP), Moldova State University (MSU), 5 Academiei Str., Chisinau, MD-2028, Moldova
| | - Maheswar Rupakheti
- Research Institute for Sustainability-Helmholtz Centre Potsdam, Potsdam, Germany
| | - Sishir Dahal
- Department of Civil Engineering, Himalaya College of Engineering, Lalitpur, Nepal
| | - Mukesh Rai
- Greenhood Nepal, New Baneshwor, Kathmandu 45305, Nepal
| | - Xiufeng Yin
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Xingna Yu
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Sabur F Abdullaev
- Physical Technical Institute of the Academy of Sciences of Tajikistan, Dushanbe, Tajikistan
| | - Jianlin Hu
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China.
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Khamala GW, Makokha JW, Boiyo R, Kumar KR. Spatiotemporal analysis of absorbing aerosols and radiative forcing over environmentally distinct stations in East Africa during 2001-2018. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 864:161041. [PMID: 36563754 DOI: 10.1016/j.scitotenv.2022.161041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/11/2022] [Accepted: 12/15/2022] [Indexed: 06/17/2023]
Abstract
East Africa (EA) suffers from the inadequate characterization of atmospheric aerosols, with far-reaching consequences of its inability to quantify precisely the impacts of these particles on regional climate. The current study aimed at characterizing absorption and radiative properties of aerosols using the long-term (2001-2018) AErosol RObotic NETwork (AERONET) and Modern-Era Retrospective analysis for Research and Applications (MERRA-2) data over three environmentally specific sites in EA. The annual mean absorption aerosol optical depth (AAOD440 nm), absorption Angstrom Exponent (AAE440-870 nm), total effective radius (REff), and total volume concentration (μm3/μm2) revealed significant spatial heterogeneity over the domain. The study domain exhibited a significant contribution of fine-mode aerosols compared to the coarse-mode particles. The monthly variation in SSA440 nm over EA explains the strength in absorption aerosols that range from moderate to strong absorbing aerosols. The aerosols exhibited significant variability over the study domain, with the dominance of absorbing fine-mode aerosols over Mbita accounting for ∼40 to ∼50 %, while weakly absorbing coarse-mode particles accounted for ∼8.2 % over Malindi. The study conclusively determined that Mbita was dominated by AAOD mainly from biomass burning in most of the months, whereas Malindi was coated with black carbon. The direct aerosol radiative forcing (DARF) retrieved from both the AERONET and MERRA-2 models showed strong cooling at the top of the atmosphere (TOA; -6 to -27 Wm-2) and the bottom of the atmosphere (BOA, -7 to -66 Wm-2). However, significant warming was noticed within the atmosphere (ATM; +14 to +76 Wm-2), an indication of the role of aerosols in regional climate change. The study contributed to understanding aerosol absorption and radiative characteristics over EA and can form the basis of other related studies over the domain and beyond.
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Affiliation(s)
- Geoffrey W Khamala
- Department of Science Technology and Engineering, Kibabii University, P.O. Box 1699-50200, Bungoma, Kenya.
| | - John W Makokha
- Department of Science Technology and Engineering, Kibabii University, P.O. Box 1699-50200, Bungoma, Kenya
| | - Richard Boiyo
- Department of Physical Sciences, Meru University of Science and Technology, P.O. Box 972-60200, Meru, Kenya; Department of Environment, Water, Energy and Natural Resources, County Government of Vihiga, Maragoli, Kenya
| | - Kanike Raghavendra Kumar
- Department of Engineering Physics, College of Engineering, Koneru Lakshmaiah Education Foundation, Vaddeswaram, 522 302 Guntur, Andhra Pradesh, India
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Merdji AB, Xu X, Lu C, Habtemicheal BA, Li J. Accuracy assessment and climatology of MODIS aerosol optical properties over North Africa. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:13449-13468. [PMID: 36129653 DOI: 10.1007/s11356-022-22997-8] [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: 12/30/2021] [Accepted: 09/07/2022] [Indexed: 06/15/2023]
Abstract
In this study, the aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) Collection 6.1 (C6.1) product was compared with ground-based measurements at five sites of the Aerosol Robotic Network (AERONET) in North Africa. The MODIS AOD showed a good correlation coefficient of ~0.78, a very small mean bias error of 0.009, and a root mean square error of 0.126 with AERONET. The Dark Target/Deep Blue (DT/DB) algorithm showed better performance at low aerosol loading while underestimating AOD at higher aerosol loading, mainly for coarse-dominated aerosol types. This work also showed the benefits of using MODIS retrievals as a reliable data source for aerosols and providing a long-term aerosol type classification. The primary aerosol type is dust emitted from the Sahara Desert, and the dusty atmosphere becomes gradually mixed with pollution aerosols approaching the coastal region. The annual mean MODIS AOD at 550 nm and Ångström exponent at 412-650 nm (AE) ranged from 0.17 to 0.45 and from 0.13 to 1.25, respectively, in Algeria between 2001 and 2019. Lower AOD (< 0.22) and higher AE (> 1) were found in the northern region, while the highest AOD (0.35 to 0.45) and the lowest AE (< 0.25) were observed over the Tanezrouft desert in southern Algeria. The seasonal mean AOD was highest in summer, while the lowest was in winter due to very high easterly and northeasterly Harmattan surface wind over Zone of Chotts and the Tidikelt Depression, respectively. The negative AOD trends observed over Algeria could be partially connected to the decline (increase) in surface (850 hPa) winds over potential dust source areas in southern Algeria.
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Affiliation(s)
- Abou Bakr Merdji
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing, China
| | - Xiaofeng Xu
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing, China.
| | - Chunsong Lu
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing, China
| | - Birhanu Asmerom Habtemicheal
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing, China
- Department of Physics, Wollo University, P.O. Box 1145, Dessie, Ethiopia
| | - Junjun Li
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science & Technology, Nanjing, China
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Rupakheti D, Rupakheti M, Rai M, Yu X, Yin X, Kang S, Orozaliev MD, Sinyakov VP, Abdullaev SF, Sulaymon ID, Hu J. Characterization of columnar aerosol over a background site in Central Asia. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 316:120501. [PMID: 36283470 DOI: 10.1016/j.envpol.2022.120501] [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: 06/10/2022] [Revised: 10/01/2022] [Accepted: 10/19/2022] [Indexed: 06/16/2023]
Abstract
Ground-based observational characterization of atmosphere aerosols over Central Asia is very limited. This study investigated the columnar aerosol characteristics over Issyk-Kul, Kyrgyzstan, a background site in Central Asia using the long-term (∼14 years: August 2007-November 2021) data acquired with the Cimel sunphotometer. The mean aerosol optical depth (AOD) and Ångström exponent (AE) during the observation period were 0.14 ± 0.10 and 1.19 ± 0.41, respectively. Both AOD and AE varied across seasons, with highest AOD in spring (0.17 ± 0.17). Regarding the aerosol types, clean continental aerosols were dominant type (65%), followed by mixed aerosols (∼19%), clean marine aerosols (∼14%), dust (0.8%), and urban/industrial and biomass burning aerosol (0.7%). The aerosol volume size distribution was bimodal indicating the influence of both anthropogenic and natural aerosols with clear dominance of coarse mode during the spring season. Mainly dust and mixed aerosols were present during high aerosol episodes while the coarse mode aerosol volume concentration was 7.5 (strong episodes) and ∼19 (extreme episodes) times higher than the whole period average. Aerosol over this background sites were from local and regional sources with some contribution of long-range transport.
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Affiliation(s)
- Dipesh Rupakheti
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, China; Institute of Fundamental Research and Studies, Kathmandu 44600, Nepal.
| | | | - Mukesh Rai
- International Centre for Integrated Mountain Development, Lalitpur, Nepal
| | - Xingna Yu
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Xiufeng Yin
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences (UCAS), Beijing 100049, China
| | - Musapar D Orozaliev
- Institute of Innovative Professions, Kyrgyz State University of Construction, Transport and Architecture Named After N Isanov, Bishkek, Kyrgyzstan
| | - Valery P Sinyakov
- Institute of Innovative Professions, Kyrgyz State University of Construction, Transport and Architecture Named After N Isanov, Bishkek, Kyrgyzstan
| | - Sabur F Abdullaev
- Physical Technical Institute of the Academy of Sciences of Tajikistan, Dushanbe, Tajikistan
| | - Ishaq Dimeji Sulaymon
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, China
| | - Jianlin Hu
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, 210044, China
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Duan J, Ju T, Wang Q, Li F, Fan J, Huang R, Liang Z, Zhang G, Geng T. Absorbable aerosols based on OMI data: a case study in three provinces of Northeast China. ENVIRONMENTAL MONITORING AND ASSESSMENT 2021; 193:479. [PMID: 34235590 DOI: 10.1007/s10661-021-09249-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/28/2021] [Indexed: 06/13/2023]
Abstract
In order to assess the status of aerosol pollution in three selected Northeast Provinces of China, Ozone Monitoring Instrument/Aura Near UV Aerosol Optical Depth and Single Scattering Albedo 1-orbit L2 Swath 13 × 24km V003 (OMAERUV) daily product data was used to evaluate (1) the ultraviolet aerosol index (UVAI) temporal and spatial distribution of the three Northeast Provinces from 2009 to 2018; (2) the potential pollution source areas of provincial capital cities; and (3) future trend changes. Furthermore, the influencing factors were also analyzed and are discussed herein. The results show that the UVAI in the Northeast Provinces exhibit an overall increasing trend, with an average annual increase rate of 2.99%. Seasonally, the UVAI increasing trend in winter is higher than in spring which in turn is higher than autumn. And summer has the least increasing trend. In addition, the external source of absorbent aerosol transmission is mainly in the southwest. Moreover, the overall UVAI remains relatively constant in the central part of the region, and increases slightly and significantly in the south and north directions. In general, spring, autumn, and winter all exhibit increasing trends in varying degrees. The difference between the forecasted and actual UVAI values in the Northeast Provinces does not exceed 10%; thus, the forecasting reliability is good. Also, UVAI has different degrees of correlation with natural factors, such as precipitation and temperature. With respect to social factors, UVAI and population density (a social factor) are positively correlated in 98.2% of the study area, demonstrating that there is a strong positive correlation between UVAI and smoke and dust emissions.
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Affiliation(s)
- Jiale Duan
- Key Laboratory of Resource Environment and Sustainable Development of Oasis, Gansu Province,College of Geography and Environmental Science, Northwest Normal University, Lanzhou, China
| | - Tianzhen Ju
- Key Laboratory of Resource Environment and Sustainable Development of Oasis, Gansu Province,College of Geography and Environmental Science, Northwest Normal University, Lanzhou, China.
| | - Qinhua Wang
- Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China
| | - Fengshuai Li
- Shandong Academy of Environmental Sciences, Jinan, China
| | - Jiachen Fan
- Key Laboratory of Resource Environment and Sustainable Development of Oasis, Gansu Province,College of Geography and Environmental Science, Northwest Normal University, Lanzhou, China
| | - Ruirui Huang
- Key Laboratory of Resource Environment and Sustainable Development of Oasis, Gansu Province,College of Geography and Environmental Science, Northwest Normal University, Lanzhou, China
| | - Zhuohong Liang
- Key Laboratory of Resource Environment and Sustainable Development of Oasis, Gansu Province,College of Geography and Environmental Science, Northwest Normal University, Lanzhou, China
| | - Guoqaing Zhang
- Key Laboratory of Resource Environment and Sustainable Development of Oasis, Gansu Province,College of Geography and Environmental Science, Northwest Normal University, Lanzhou, China
| | - Tunyang Geng
- Key Laboratory of Resource Environment and Sustainable Development of Oasis, Gansu Province,College of Geography and Environmental Science, Northwest Normal University, Lanzhou, China
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Khan R, Kumar KR, Zhao T. Assessment of variations of air pollutant concentrations during the COVID-19 lockdown and impact on urban air quality in South Asia. URBAN CLIMATE 2021; 38:100908. [PMID: 36570862 PMCID: PMC9764092 DOI: 10.1016/j.uclim.2021.100908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 06/10/2021] [Accepted: 06/29/2021] [Indexed: 05/28/2023]
Abstract
Quantifying the variations of atmospheric aerosols and trace gas concentrations with the impact of lockdown due to the Coronavirus disease of 2019 (COVID-19) pandemic is crucial in understanding urban air quality. For this purpose, we utilized the multi-instrumental approach of satellite remote sensing and reanalysis model data to examine the spatial and temporal patterns of major air pollutants during December 2019-June 2020 in South Asia. The lockdown has to lead to a considerable decrease in aerosol optical thickness (AOT) over South China (-18.92%) and Indo-Gangetic Plain (IGP; -24.29%) compared to its ordinary level for a couple of weeks. Noticeable reductions in tropospheric NO2 are observed over the Pearl River Delta (PRD; -0.3/cm2) followed by Central China (CC) with -0.21/cm2and IGP (-0.085/cm2), and the lowest (-0.0008/cm2) in the Tibetan Plateau (TP) region. The changes observed in PM2.5 and SO2 levels (from -58.56% to - 63.64%) are attributed to the decrease in anthropogenic emissions, vehicular exhaust, and industrial activities. However, the BC concentrations are reduced by approximately halved of its ordinary levels in the IGP (-2.28 μg/m3) followed by YRD (-1.56 μg/m3), CC (-1.5 μg/m3), NCP (-1.29 μg/m3), and PRD (-0.78 μg/m3) regions. The total column O3 predominantly increased from 262.68 to 285.53DU, 323.00 to 343.00DU, and 245.00 to 265.00DU in the YRD, NCP, and IGP areas. This is mainly associated with solar radiation, meteorological factors, and an unprecedented reduction in NOx during the lockdown period.
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Affiliation(s)
- Rehana Khan
- Collaborative Innovation Centre on Forecast and Evaluation of Meteorological Disasters, Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), International Joint Laboratory on Climate and Environment Change (ILCEC), Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China
- Department of Physics, Higher Education, Government of Khyber Pakhtunkhwa, Peshawar 25000, Pakistan
| | - Kanike Raghavendra Kumar
- Department of Physics, Koneru Lakshmaiah Education Foundation (KLEF), Vaddeswaram, 522502 Guntur, Andhra Pradesh, India
- Collaborative Innovation Centre on Forecast and Evaluation of Meteorological Disasters, Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), International Joint Laboratory on Climate and Environment Change (ILCEC), Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China
| | - Tianliang Zhao
- Collaborative Innovation Centre on Forecast and Evaluation of Meteorological Disasters, Key Laboratory of Meteorological Disaster, Ministry of Education (KLME), International Joint Laboratory on Climate and Environment Change (ILCEC), Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China
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9
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Towards On-Board Hyperspectral Satellite Image Segmentation: Understanding Robustness of Deep Learning through Simulating Acquisition Conditions. REMOTE SENSING 2021. [DOI: 10.3390/rs13081532] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Although hyperspectral images capture very detailed information about the scanned objects, their efficient analysis, transfer, and storage are still important practical challenges due to their large volume. Classifying and segmenting such imagery are the pivotal steps in virtually all applications, hence developing new techniques for these tasks is a vital research area. Here, deep learning has established the current state of the art. However, deploying large-capacity deep models on-board an Earth observation satellite poses additional technological challenges concerned with their memory footprints, energy consumption requirements, and robustness against varying-quality image data, with the last problem being under-researched. In this paper, we tackle this issue, and propose a set of simulation scenarios that reflect a range of atmospheric conditions and noise contamination that may ultimately happen on-board an imaging satellite. We verify their impact on the generalization capabilities of spectral and spectral-spatial convolutional neural networks for hyperspectral image segmentation. Our experimental analysis, coupled with various visualizations, sheds more light on the robustness of the deep models and indicate that specific noise distributions can significantly deteriorate their performance. Additionally, we show that simulating atmospheric conditions is key to obtaining the learners that generalize well over image data acquired in different imaging settings.
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10
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Interdecadal Changes in Aerosol Optical Depth over Pakistan Based on the MERRA-2 Reanalysis Data during 1980–2018. REMOTE SENSING 2021. [DOI: 10.3390/rs13040822] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The spatiotemporal evolution and trends in aerosol optical depth (AOD) over environmentally distinct regions in Pakistan are investigated for the period 1980–2018. The AOD data for this period was obtained from the Modern-era retrospective analysis for research and applications, version 2 (MERRA-2) reanalysis atmospheric products, together with the Moderate-resolution imaging spectroradiometer (MODIS) retrievals. The climatology of AODMERRA-2 is analyzed in three different contexts: the entire study domain (Pakistan), six regions within the domain, and 12 cities chosen from the entire study domain. The time-series analysis of the MODIS and MERRA-2 AOD data shows similar patterns in individual cities. The AOD and its seasonality vary strongly across Pakistan, with the lowest (0.05 ± 0.04) and highest (0.40 ± 0.06) in the autumn and summer seasons over the desert and the coastal regions, respectively. During the study period, the annual AOD trend increased between 0.002 and 0.012 year−1. The increase of AOD is attributed to an increase in population and emissions from natural and/or anthropogenic sources. A general increase in the annual AOD over the central to lower Indus Basin is ascribed to the large contribution of dust particles from the desert. During winter and spring, a significant decrease in the AOD was observed in the northern regions of Pakistan. The MERRA-2 and MODIS trends (2002–2018) were compared, and the results show visible differences between the AOD datasets due to theuseof different versions and collection methods. Overall, the present study provides insight into the regional differences of AOD and its trends with the pronounced seasonal behavior across Pakistan.
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11
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Long-Term Variation of Black Carbon Absorption Aerosol Optical Depth from AERONET Data over East Asia. REMOTE SENSING 2020. [DOI: 10.3390/rs12213551] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Absorption aerosol optical depth induced by black carbon (AAODBC) was retrieved using the depolarization ratio and single scattering albedo provided by the Aerosol Robotic Network (AERONET) inversion products over East Asia. Our analysis considered AERONET data from six sites in East Asia that are mostly affected by anthropogenic pollution, black carbon (BC) emissions, and natural mineral dust, during the period 2001–2018. We identified a rapid reduction in total aerosol optical depth (AODT) of −0.0106 yr−1 over Beijing, whereas no considerable trend was observed at the Korean and Japanese sites. The long-term data for AAODBC showed decreasing trends at all sites. We conclude that successful emission control policies were the major underlying driver of AODT and AAODBC reductions over East Asia, particularly in China, during the study period. Values of the AAODBC/AODT ratio revealed that, although these policies were successful, the Chinese government needs to undertake stricter measures toward reducing BC emissions. We found that AAODBC follows seasonal trends, peaking in the colder months. This suggests that in East Asia, particularly in China, domestic coal burning is still of concern.
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Rupakheti D, Rupakheti M, Abdullaev SF, Yin X, Kang S. Columnar aerosol properties and radiative effects over Dushanbe, Tajikistan in Central Asia. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 265:114872. [PMID: 32497948 DOI: 10.1016/j.envpol.2020.114872] [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: 04/03/2020] [Revised: 05/14/2020] [Accepted: 05/22/2020] [Indexed: 06/11/2023]
Abstract
This paper presents the results of the study on columnar aerosol optical and physical properties and radiative effects directly observed over Dushanbe, the capital city of Tajikistan, a NASA AERONET site (equipped with a CIMEL sunphotometer) in Central Asia. The average aerosol optical depth (AOD) and Ångström exponent (AE) during the observation period from July 2010 to April 2018 were found to be 0.28 ± 0.20 and 0.82 ± 0.40, respectively. The highest seasonal AOD (0.32 ± 0.24), accompanied by the lowest average AE (0.61 ± 0.25) and fine-mode fraction in AOD (0.39), was observed during summer due to the influence of coarse particles like dust from arid regions. Fine particles were found in significant amounts during winter. The 'mixed aerosol' was identified as the dominant aerosol type with presence of 'dust aerosol' during summer and autumn seasons. Aerosol properties like volume size distribution, single scattering albedo, asymmetry parameter and refractive index suggested the influence of coarse particles (during summer and autumn). Most of the air masses reaching this site transported local and regional emissions, including from beyond Central Asia, explaining the presence of various aerosol types in Dushanbe's atmosphere. The seasonal aerosol radiative forcing efficiency (ARFE) in the atmosphere was found high (>100 Wm-2) and consistent throughout the year. Consequently, this resulted in similar seasonally coherent high atmospheric solar heating rate (HR) of 1.5 K day-1 during summer-autumn-winter, and ca. 0.9 K day-1 during spring season. High ARFE and HR values indicate that atmospheric aerosols could exert significant implications to regional air quality, climate and cryosphere over the central Asian region and downwind Tianshan and Himalaya-Tibetan Plateau mountain regions with sensitive ecosystems.
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Affiliation(s)
- Dipesh Rupakheti
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | | | - Sabur F Abdullaev
- Physical Technical Institute of the Academy of Sciences of Tajikistan, Dushanbe, Tajikistan
| | - Xiufeng Yin
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, 100101, China.
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Spatiotemporal Trends of Aerosols over Urban Regions in Pakistan and Their Possible Links to Meteorological Parameters. ATMOSPHERE 2020. [DOI: 10.3390/atmos11030306] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aerosol optical depth (AOD) has become one of the most crucial parameters for climate change assessment on regional and global scales. The present study investigates trends in AOD using long-term data derived from moderate resolution imaging spectro-radiometer (MODIS) over twelve regions in Pakistan. Different statistical tests are used to assess the annual and seasonal trends in AOD. Results reveal increasing AOD trends over most of the selected regions with an obvious increase over the north and northeastern parts of the study area. Annually, increasing trends (0.0002–0.0047 year−1) were observed over seven regions, with three being statistically significant. All the selected regions experience increasing AOD trends during the winter season with six being statistically significant while during the summer season seven regions experience increasing AOD trends and the remaining five exhibit the converse with two being statistically significant. The changes in the sign and magnitude of AOD trends have been attributed to prevailing meteorological conditions. The decreasing rainfall and increasing temperature trends mostly support the increasing AOD trend over the selected regions. The high/low AOD phases during the study period may be ascribed to the anomalies in mid-tropospheric relative humidity and wind fields. The summer season is generally characterized by high AOD with peak values observed over the regions located in central plains, which can be attributed to the dense population and enhanced concentration of industrial and vehicular emissions over this part of the study area. The results derived from the present study give an insight into aerosol trends and could form the basis for aerosol-induced climate change assessment over the study area.
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