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Pani SK, Huang HY, Wang SH, Holben BN, Lin NH. Long-term observation of columnar aerosol optical properties over the remote South China Sea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167113. [PMID: 37717748 DOI: 10.1016/j.scitotenv.2023.167113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 09/13/2023] [Accepted: 09/13/2023] [Indexed: 09/19/2023]
Abstract
The South China Sea (SCS) is a receptor of pollution sources from various parts of Asia and is heavily impacted by strong meteorological systems, which thus dictate aerosol variability over the region. This study analyzes long-term aerosol optical properties observed at Dongsha Island (a representative site in northern SCS) from 2009 to 2021 and Taiping Island (a representative site in southern SCS) from 2012 to 2021 to better apprehend the temporal evolution of columnar aerosols over the SCS. The noticeable difference in loadings, optical properties, and compositions of aerosols between northern and southern SCS was due to the influence of dissimilar emission sources and transport mechanisms. Column-integrated aerosol optical depth (AOD) over northern SCS (range of monthly mean at 500 nm; 0.12-0.51) was significantly greater than southern SCS (0.09-0.21). The maximum AOD in March (0.51 ± 0.28) at Dongsha was attributed to westerlies coupled with biomass-burning (BB) emissions from peninsular Southeast Asia, whereas the maximum AOD at Taiping in September (0.21 ± 0.25) was owing to various pollution from the Philippines, Malaysia, and Indonesia. Fine-mode aerosol dominated over northern SCS (range of monthly mean Angstrom exponent for 440-870 nm: 0.85-1.36) due to substantial influence from continental sources including anthropogenic and BB emissions while coarse-mode particles dominated over southern SCS (0.54-1.28) due to relatively more influence from marine source. More absorbing columnar aerosols prevailed over northern SCS (range of monthly mean single scattering albedo at 675 nm: 0.92-0.99) compared to southern SCS (0.95-0.98) owing to differences in aerosol composition with respect to sources. Special pollution events showcased possible significant impacts on marine ecosystems and regional climate. This study encourages the establishment of more ground-based aerosol monitoring networks and the inclusion of modeling simulations to comprehend the complex nature of aerosol over this vast marginal sea.
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Affiliation(s)
- Shantanu Kumar Pani
- Department of Atmospheric Sciences, National Central University, Taoyuan 32001, Taiwan
| | - Hsiang-Yu Huang
- Department of Atmospheric Sciences, National Central University, Taoyuan 32001, Taiwan
| | - Sheng-Hsiang Wang
- Department of Atmospheric Sciences, National Central University, Taoyuan 32001, Taiwan; Center for Environmental Monitoring and Technology, National Central University, Taoyuan 32001, Taiwan.
| | - Brent N Holben
- Goddard Space Flight Center, NASA, Greenbelt, MD 20771, USA
| | - Neng-Huei Lin
- Department of Atmospheric Sciences, National Central University, Taoyuan 32001, Taiwan; Center for Environmental Monitoring and Technology, National Central University, Taoyuan 32001, Taiwan.
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Limited influence of irrigation on pre-monsoon heat stress in the Indo-Gangetic Plain. Nat Commun 2022; 13:4275. [PMID: 35879272 PMCID: PMC9314405 DOI: 10.1038/s41467-022-31962-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 07/12/2022] [Indexed: 11/23/2022] Open
Abstract
Hot extremes are anticipated to be more frequent and more intense under climate change, making the Indo-Gangetic Plain of India, with a 400 million population, vulnerable to heat stress. Recent studies suggest that irrigation has significant cooling and moistening effects over this region. While large-scale irrigation is prevalent in the Indo-Gangetic Plain during the two major cropping seasons, Kharif (Jun-Sep) and Rabi (Nov-Feb), hot extremes are reported in the pre-monsoon months (Apr-May) when irrigation activities are minimal. Here, using observed irrigation data and regional climate model simulations, we show that irrigation effects on heat stress during pre-monsoon are 4.9 times overestimated with model-simulated irrigation as prescribed in previous studies. We find that irrigation increases relative humidity by only 2.5%, indicating that irrigation is a non-crucial factor enhancing the moist heat stress. On the other hand, we detect causal effects of aerosol abundance on the daytime land surface temperature. Our study highlights the need to consider actual irrigation data in testing model-driven hypotheses related to the land-atmosphere feedback driven by human water management. Pre-monsoon irrigation over the Indo-Gangetic Plain is often misrepresented in model-driven hypothesis. Using actual census-based data and realistic model simulations, the authors show that irrigation has limited role in enhancing heat stress in the region.
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Maharjan L, Kang S, Tripathee L, Gul C, Zheng H, Li Q, Chen P, Rai M, Santos E. Atmospheric particle-bound polycyclic aromatic compounds over two distinct sites in Pakistan: Characteristics, sources and health risk assessment. J Environ Sci (China) 2022; 112:1-15. [PMID: 34955192 DOI: 10.1016/j.jes.2021.04.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/21/2021] [Accepted: 04/22/2021] [Indexed: 06/14/2023]
Abstract
Much attention is drawn to polycyclic aromatic hydrocarbons (PAHs) as an air pollutant due to their toxic, mutagenic and carcinogenic properties. Therefore, to understand the levels, seasonality, sources and potential health risk of PAHs in two distinct geographical locations at Karachi and Mardan in Pakistan, total suspended particle (TSP) samples were collected for over one year period. The average total PAH concentrations were 31.5 ± 24.4 and 199 ± 229 ng/m3 in Karachi and Mardan, respectively. The significantly lower concentration in Karachi was attributed to diffusion and dilution of the PAHs by the influence of clean air mass from the Arabian sea and high temperature, enhancing the volatilization of the particle phase PAHs to the gas phase. Conversely, the higher concentration (~6 times) in Mardan was due to large influence from local and regional emission sources. A clear seasonality was observed at both the sites, with the higher values in winter and post-monsoon due to higher emissions and less scavenging, and lower values during monsoon season due to the dilution effect. Diagnostic ratios and principal component analysis indicated that PAHs in both sites originated from traffic and mixed combustion sources (fossil fuels and biomass). The average total BaP equivalent concentrations (BaPeq) in Karachi and Mardan were 3.26 and 34 ng/m3, respectively, which were much higher than the WHO guideline of 1 ng/m3. The average estimates of incremental lifetime cancer risk from exposure to airborne BaPeq via inhalation indicated a risk to human health from atmospheric PAHs at both sites.
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Affiliation(s)
- Linda Maharjan
- 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, Beijing 100049, 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, Beijing 100049, China; Chinese Academy of Sciences (CAS) Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100085, China
| | - Lekhendra Tripathee
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Himalayan Environment Research Institute, Kathmandu 44600, Nepal.
| | - Chaman Gul
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; Reading Academy, Nanjing University of Information Science & Technology, Nanjing, Jiangsu 210044, China
| | - Huijun Zheng
- 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, Beijing 100049, China
| | - Quanlian Li
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Mukesh Rai
- 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, Beijing 100049, China
| | - Ewerton Santos
- Departamento de Química, Universidade Federal de Sergipe, São Cristóvão, Sergipe SE 49100-000, Brazil
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Anwar MN, Shabbir M, Tahir E, Iftikhar M, Saif H, Tahir A, Murtaza MA, Khokhar MF, Rehan M, Aghbashlo M, Tabatabaei M, Nizami AS. Emerging challenges of air pollution and particulate matter in China, India, and Pakistan and mitigating solutions. JOURNAL OF HAZARDOUS MATERIALS 2021; 416:125851. [PMID: 34492802 DOI: 10.1016/j.jhazmat.2021.125851] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 03/11/2021] [Accepted: 04/06/2021] [Indexed: 06/13/2023]
Abstract
This study examines point and non-point sources of air pollution and particulate matter and their associated socioeconomic and health impacts in South Asian countries, primarily India, China, and Pakistan. The legislative frameworks, policy gaps, and targeted solutions are also scrutinized. The major cities in these countries have surpassed the permissible limits defined by WHO for sulfur dioxide, carbon monoxide, particulate matter, and nitrogen dioxide. As a result, they are facing widespread health problems, disabilities, and causalities at extreme events. Populations in these countries are comparatively more prone to air pollution effects because they spend more time in the open air, increasing their likelihood of exposure to air pollutants. The elevated level of air pollutants and their long-term exposure increases the susceptibility to several chronic/acute diseases, i.e., obstructive pulmonary diseases, acute respiratory distress, chronic bronchitis, and emphysema. More in-depth spatial-temporal air pollution monitoring studies in China, India, and Pakistan are recommended. The study findings suggest that policymakers at the local, national, and regional levels should devise targeted policies by considering all the relevant parameters, including the country's economic status, local meteorological conditions, industrial interests, public lifestyle, and national literacy rate. This approach will also help design and implement more efficient policies which are less likely to fail when brought into practice.
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Affiliation(s)
- Muhammad Naveed Anwar
- Sustainable Development Study Centre, Government College University, Lahore 54000, Pakistan.
| | - Muneeba Shabbir
- Sustainable Development Study Centre, Government College University, Lahore 54000, Pakistan
| | - Eza Tahir
- Sustainable Development Study Centre, Government College University, Lahore 54000, Pakistan
| | - Mahnoor Iftikhar
- Sustainable Development Study Centre, Government College University, Lahore 54000, Pakistan
| | - Hira Saif
- Sustainable Development Study Centre, Government College University, Lahore 54000, Pakistan
| | - Ajwa Tahir
- Sustainable Development Study Centre, Government College University, Lahore 54000, Pakistan
| | - Malik Ashir Murtaza
- Sustainable Development Study Centre, Government College University, Lahore 54000, Pakistan
| | - Muhammad Fahim Khokhar
- Institute of Environmental Sciences and Engineering, National University of Sciences and Technology, Islamabad 44000, Pakistan
| | - Mohammad Rehan
- Center of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah, Saudi Arabia
| | - Mortaza Aghbashlo
- Department of Mechanical Engineering of Agricultural Machinery, Faculty of Agricultural Engineering and Technology, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran
| | - Meisam Tabatabaei
- Higher Institution Centre of Excellence (HICoE), Institute of Tropical Aquaculture and Fisheries (AKUATROP), Universiti Malaysia Terengganu, 21030 Kuala Nerus, Terengganu, Malaysia; Henan Province Forest Resources Sustainable Development and High-value Utilization Engineering Research Center, School of Forestry, Henan Agricultural University, Zhengzhou 450002, China; Biofuel Research Team (BRTeam), Terengganu, Malaysia; Microbial Biotechnology Department, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education, and Extension Organization (AREEO), Karaj, Iran
| | - Abdul-Sattar Nizami
- Sustainable Development Study Centre, Government College University, Lahore 54000, Pakistan.
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Investigating the Aerosol Optical Depth and Angstrom Exponent and Their Relationships with Meteorological Parameters Over Lahore in Pakistan. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES INDIA SECTION A-PHYSICAL SCIENCES 2019. [DOI: 10.1007/s40010-018-0575-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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How Long should the MISR Record Be when Evaluating Aerosol Optical Depth Climatology in Climate Models? REMOTE SENSING 2018. [DOI: 10.3390/rs10091326] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study used the nearly continuous 17-year observation record from the Multi- angle Imaging SpectroRadiometer (MISR) instrument on the National Aeronautics and Space Administration (NASA) Terra Earth Observing System satellite to determine which temporal subsets are long enough to define statistically stable speciated aerosol optical depth (AOD) climatologies (i.e., AOD by particle types) for purposes of climate model evaluation. A random subsampling of seasonally averaged total and speciated AOD retrievals was performed to quantitatively assess the statistical stability in the climatology, represented by the minimum record length required for the standard deviation of the subsampled mean AODs to be less than a certain threshold. Our results indicate that the multi-year mean speciated AOD from MISR is stable on a global scale; however, there is substantial regional variability in the assessed stability. This implies that in some regions, even 17 years may not provide a long enough sample to define regional mean total and speciated AOD climatologies. We further investigated the agreement between the statistical stability of total AOD retrievals from MISR and the Moderate Resolution Imaging Spectroradiometer (MODIS), also on the NASA Terra satellite. The difference in the minimum record lengths between MISR and MODIS climatologies of total AOD is less than three years for most of the globe, with the exception of certain regions. Finally, we compared the seasonal cycles in the MISR total and speciated AODs with those simulated by three global chemistry transport models in the regions of climatologically stable speciated AODs. We found that only one model reproduced the observed seasonal cycles of the total and non-absorbing AODs over East China, but the seasonal cycles in total and dust AODs in all models are similar to those from MISR in Western Africa. This work provides a new method for considering the statistical stability of satellite-derived climatologies and illustrates the value of MISR’s speciated AOD data record for evaluating aerosols in global models.
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David LM, Ravishankara AR, Kodros JK, Venkataraman C, Sadavarte P, Pierce JR, Chaliyakunnel S, Millet DB. Aerosol Optical Depth Over India. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2018; 123:3688-3703. [PMID: 33614367 PMCID: PMC7894385 DOI: 10.1002/2017jd027719] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Tropospheric aerosol optical depth (AOD) over India was simulated by Goddard Earth Observing System (GEOS)-Chem, a global 3-D chemical-transport model, using SMOG (Speciated Multi-pOllutant Generator from Indian Institute of Technology Bombay) and GEOS-Chem (GC) (current inventories used in the GEOS-Chem model) inventories for 2012. The simulated AODs were ~80% (SMOG) and 60% (GC) of those measured by the satellites (Moderate Resolution Imaging Spectroradiometer and Multi-angle Imaging SpectroRadiometer). There is no strong seasonal variation in AOD over India. The peak AOD values are observed/simulated during summer. The simulated AOD using SMOG inventory has particulate black and organic carbon AOD higher by a factor ~5 and 3, respectively, compared to GC inventory. The model underpredicted coarse-mode AOD but agreed for fine-mode AOD with Aerosol Robotic Network data. It captured dust only over Western India, which is a desert, and not elsewhere, probably due to inaccurate dust transport and/or noninclusion of other dust sources. The calculated AOD, after dust correction, showed the general features in its observed spatial variation. Highest AOD values were observed over the Indo-Gangetic Plain followed by Central and Southern India with lowest values in Northern India. Transport of aerosols from Indo-Gangetic Plain and Central India into Eastern India, where emissions are low, is significant. The major contributors to total AOD over India are inorganic aerosol (41-64%), organic carbon (14-26%), and dust (7-32%). AOD over most regions of India is a factor of 5 or higher than over the United States.
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Affiliation(s)
- Liji Mary David
- Department of Chemistry and Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - A R Ravishankara
- Department of Chemistry and Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - John K Kodros
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Chandra Venkataraman
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Pankaj Sadavarte
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
- Institute for Advanced Sustainability Studies, Potsdam, Germany
| | - Jeffrey R Pierce
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - Sreelekha Chaliyakunnel
- Department of Soil, Water, and Climate, University of Minnesota, Twin Cities, St. Paul, MN, USA
| | - Dylan B Millet
- Department of Soil, Water, and Climate, University of Minnesota, Twin Cities, St. Paul, MN, USA
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