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Tyagi G, Babu KN, Solanki HA. Monitoring bio-optical response of coastal waters surrounding the Indian subcontinent to atmospheric dust deposition using satellite data. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:5523-5535. [PMID: 31853851 DOI: 10.1007/s11356-019-07134-2] [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: 05/20/2019] [Accepted: 11/20/2019] [Indexed: 06/10/2023]
Abstract
The paper investigates the impact of atmospheric dust deposition on ocean biological productivity in association with oceanic supply of nutrients over specific regions of the Arabian Sea (20°N, 69°E) and the Bay of Bengal (20°N, 87°E) during wintertime (November-March) from the year 2012 to 2017 using satellite-based observations. During winter, selected regions are characterized by higher Chlorophyll-a (Chl-a) and major oceanic vertical supply of nutrients. Moderate Resolution Imaging Spectroradiometer onboard Aqua space-platform is used to obtain Chl-a and aerosol optical depth (AOD) data. Blended Chl-a daily product from various satellite sensors is also used. There are a total of nine cases (seven cases of the Arabian Sea region and two cases of the Bay of Bengal region) where episodic Chl-a enhancements following high AOD values are observed. Chl-a maxima lag behind AOD maxima by 1 to 4 days. Modern-Era Retrospective analysis for Research and Applications (Version-2) is used for AOD and dust deposition flux estimation. Estimated dust deposition flux ranges between 0.44 and 27.68 mg m-2 day-1.
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Affiliation(s)
- Geetika Tyagi
- Space Applications Centre, ISRO, Ahmedabad, Gujarat, 380015, India.
- Gujarat University, Ahmedabad, Gujarat, 380009, India.
| | - K N Babu
- Space Applications Centre, ISRO, Ahmedabad, Gujarat, 380015, India
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Prijith SS, Moorthy KK, Babu SNS, Satheesh SK. Characterization of particulate matter and black carbon over Bay of Bengal during summer monsoon: results from the OMM cruise experiment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:33162-33171. [PMID: 30255263 DOI: 10.1007/s11356-018-3226-1] [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: 04/04/2018] [Accepted: 09/13/2018] [Indexed: 06/08/2023]
Abstract
Total and size-segregated particulate matter (PM) and black carbon (BC) concentrations over the Bay of Bengal (BoB) have been measured in the summer monsoon (August-September 2014) onboard a scientific cruise conducted as a part of the Ocean Monsoon and Mixing (OMM) experiment. Role of long-range transport and prevailing meteorology in producing the observed spatio-temporal features is inferred by synthesizing the results of in situ observations in conjunction with the wind components from Modern Era Retrospective Analysis for Research and Applications (MERRA), rainfall data from Tropical Rainfall Measuring Mission (TRMM), surface BC concentration and BC Aerosol Optical Thickness (AOTBC) from MERRA2 and HYSPLIT back trajectory and dispersion model analysis. Mean values of total PM and BC mass concentrations are observed to be ~ 21.4 μgm-3 and ~ 393ngm-3 respectively. The study has revealed significant influence of monsoon rainfall (over the measurement locations and regions through which transport occurred) on the concentration of both PM and BC over northern BoB. Results also indicate transport of aerosols with significant anthropogenic fraction, from the land regions at west to the BoB. A comprehensive analysis showed that while an eastward wind (westerly) from the Indian mainland produced an increase in PM2.5 over northern BoB, a southerly wind, mostly from the Indian Ocean, caused a decrease in concentration of PM2.5. Spectral variation of absorption coefficients of aerosols reveals that most of the BC over BoB is associated with fossil fuel combustion. Prevailing strong surface-level convergence (associated with a low-level anticyclone) resulted in accumulation and consequent enhancement of aerosol concentration over central and northern BoB during the study period. In addition, horizontal flow rates estimated across western boundary of BoB using AOTBC from MERRA2 for 10 years revealed an increasing trend in BC transport from the mainland leading to a gradual buildup in BC concentration over the regions of BoB.
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Affiliation(s)
| | | | | | - Sreedharan Krishnakumari Satheesh
- Centre for Atmospheric & Oceanic Sciences, Indian Institute of Science, Bengaluru, 560012, India
- Divecha Centre for Climate Change, Indian Institute of Science, Bengaluru, 560012, India
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Prijith SS, Rao PVN, Mohan M, Sai MVRS, Ramana MV. Trends of absorption, scattering and total aerosol optical depths over India and surrounding oceanic regions from satellite observations: role of local production, transport and atmospheric dynamics. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:18147-18160. [PMID: 29691752 DOI: 10.1007/s11356-018-2032-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 04/13/2018] [Indexed: 06/08/2023]
Abstract
The study examines trends of scattering, absorption and total aerosol optical depths (SAOD, AAOD and AOD) over India and surrounding oceanic regions and explores role of local production, long-range transport and atmospheric dynamics on observed trends. Long-term satellite observations are used to estimate trends and assess their statistical significance. Significant spatial and seasonal changes are observed in trends of SAOD, AAOD and AOD. AOD is observed to be increasing during post monsoon and winter over most of the land mass and surrounding oceanic regions, whereas decreasing trends over land and increasing trends over oceanic regions are observed in pre-monsoon and summer months. In general, SAOD and AAOD show similar trends (if there is any) as that of AOD over most of the regions in most of the months. Strongest positive trends over land regions are observed in November with trend of AOD greater than 0.01 year-1, especially over Indo-Gangetic Plain (IGP). Increase of AOD over IGP in post monsoon is contributed significantly by absorbing aerosols with rate of increase ~ 0.005 AAOD year-1. AAODs are observed to be increasing over Arabian Sea and Bay of Bengal (BoB) in December also, with rate ~ 0.003 AAOD year-1. Strongest positive trends over Arabian Sea and BoB are observed in June with rate of increase greater than 0.02 AOD year-1, whereas strong negative trends are observed over north-west India in the same period with rate of decrease greater than 0.02 AOD year-1. Over IGP, AOD, AAOD and SAOD show contrasting trends in winter and summer seasons. AAOD exhibits strongest decreasing trend over IGP during April-June. Positive trends of AOD over Arabian Sea and BoB are favoured significantly by changes in circulation dynamics. Atmospheric convergence is observed to be strengthening over these regions in April and June, leading to more accumulation and hence positive trends of AOD. Aerosol transport over to the Arabian Sea is observed to be enhancing and contributing significantly to AOD increase over the Arabian Sea in pre-monsoon and summer months. Enhancement in aerosol transport over to the Arabian Sea is observed in pre-monsoon at higher altitudes above 3 km, whereas it is observed in summer at lower levels. However, decreasing trends of AOD over north-west India and IGP during pre-monsoon and summer are observed to be due to decrease in aerosol transport from the continental regions at the west.
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Affiliation(s)
| | | | | | | | - Muvva Venkata Ramana
- National Remote Sensing Centre, Indian Space Research Organisation, Hyderabad, India
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Chandra S, Kulshrestha MJ, Singh R, Singh N. Chemical characteristics of trace metals in PM 10 and their concentrated weighted trajectory analysis at Central Delhi, India. J Environ Sci (China) 2017; 55:184-196. [PMID: 28477812 DOI: 10.1016/j.jes.2016.06.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 02/17/2016] [Accepted: 06/08/2016] [Indexed: 06/07/2023]
Abstract
Trace metals associated with PM10 aerosols and their variation during day and nighttime as well as during different seasons have been studied for the year 2012. PCA analysis suggested 5 PCs, which accounted for 86.8% cumulative variance. PC1 accounted for 30% with a significant loading of metals of anthropogenic origin, while PC2 showed 28% variance with the loading of metals of crustal origin. These trace metals showed seasonal distinct day and night time characteristics. The concentrations of Cu, Pb, and Cd were found to be higher during nighttime in all the seasons. Only Fe was observed with significantly higher mean concentrations during daytime of all seasons except monsoon. The highest mean values of Cu, Cd, Zn, and Pb during post-monsoon might be attributed to winds advection over the regions of waste/biomass burning and industrial activities in Punjab and Haryana regions. Furthermore, concentration weighted trajectory analysis suggested that metals of crustal origin were contributed by long-range transport while metals of anthropogenic and industrial activities were contributed by regional/local source regions.
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Affiliation(s)
- Subhash Chandra
- CSIR-National Physical Laboratory, New Delhi 110012, India; Academy of Scientific and Innovative Research (AcSIR), CSIR - National Physical Laboratory, (CSIR-NPL) Campus, New Delhi 110012, India.
| | - Monika J Kulshrestha
- CSIR-National Physical Laboratory, New Delhi 110012, India; Academy of Scientific and Innovative Research (AcSIR), CSIR - National Physical Laboratory, (CSIR-NPL) Campus, New Delhi 110012, India.
| | - Ruchi Singh
- CSIR-National Physical Laboratory, New Delhi 110012, India
| | - Nahar Singh
- CSIR-National Physical Laboratory, New Delhi 110012, India
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Emetere ME, Akinyemi ML, Akin-Ojo O. Parametric retrieval model for estimating aerosol size distribution via the AERONET, LAGOS station. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2015; 207:381-390. [PMID: 26452005 DOI: 10.1016/j.envpol.2015.09.047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 09/18/2015] [Accepted: 09/21/2015] [Indexed: 06/05/2023]
Abstract
The size characteristics of atmospheric aerosol over the tropical region of Lagos, Southern Nigeria were investigated using two years of continuous spectral aerosol optical depth measurements via the AERONET station for four major bands i.e. blue, green, red and infrared. Lagos lies within the latitude of 6.465°N and longitude of 3.406°E. Few systems of dispersion model was derived upon specified conditions to solve challenges on aerosols size distribution within the Stokes regime. The dispersion model was adopted to derive an aerosol size distribution (ASD) model which is in perfect agreement with existing model. The parametric nature of the formulated ASD model shows the independence of each band to determine the ASD over an area. The turbulence flow of particulates over the area was analyzed using the unified number (Un). A comparative study via the aid of the Davis automatic weather station was carried out on the Reynolds number, Knudsen number and the Unified number. The Reynolds and Unified number were more accurate to describe the atmospheric fields of the location. The aerosols loading trend in January to March (JFM) and August to October (ASO) shows a yearly 15% retention of aerosols in the atmosphere. The effect of the yearly aerosol retention can be seen to partly influence the aerosol loadings between October and February.
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Affiliation(s)
- Moses Eterigho Emetere
- Department of Physics, Covenant University Canaan Land, P.M.B 1023, Ota, 122333, Nigeria.
| | - Marvel Lola Akinyemi
- Department of Physics, Covenant University Canaan Land, P.M.B 1023, Ota, 122333, Nigeria
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Adesina AJ, Kumar KR, Sivakumar V, Griffith D. Direct radiative forcing of urban aerosols over Pretoria (25.75°S, 28.28°E) using AERONET Sunphotometer data: first scientific results and environmental impact. J Environ Sci (China) 2014; 26:2459-2474. [PMID: 25499494 DOI: 10.1016/j.jes.2014.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 03/26/2014] [Accepted: 04/17/2014] [Indexed: 06/04/2023]
Abstract
The present study uses the data collected from Cimel Sunphotometer of Aerosol Robotic Network (AERONET) for the period from January to December, 2012 over an urban site, Pretoria (PTR; 25.75°S, 28.28°E, 1449 m above sea level), South Africa. We found that monthly mean aerosol optical depth (AOD, τ(a)) exhibits two maxima that occurred in summer (February) and winter (August) having values of 0.36 ± 0.19 and 0.25 ± 0.14, respectively, high-to-moderate values in spring and thereafter, decreases from autumn with a minima in early winter (June) 0.12 ± 0.07. The Angstrom exponents (α440-870) likewise, have its peak in summer (January) 1.70 ± 0.21 and lowest in early winter (June) 1.38 ± 0.26, while the columnar water vapor (CWV) followed AOD pattern with high values (summer) at the beginning of the year (February, 2.10 ± 0.37 cm) and low values (winter) in the middle of the year (July, 0.66 ± 0.21 cm). The volume size distribution (VSD) in the fine-mode is higher in the summer and spring seasons, whereas in the coarse mode the VSD is higher in the winter and lower in the summer due to the hygroscopic growth of aerosol particles. The single scattering albedo (SSA) ranged from 0.85 to 0.96 at 440 nm over PTR for the entire study period. The averaged aerosol radiative forcing (ARF) computed using SBDART model at the top of the atmosphere (TOA) was -8.78 ± 3.1 W/m², while at the surface it was -25.69 ± 8.1 W/m² leading to an atmospheric forcing of +16.91 ± 6.8 W/m², indicating significant heating of the atmosphere with a mean of 0.47K/day.
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Affiliation(s)
- Ayodele Joseph Adesina
- Discipline of Physics, School of Chemistry and Physics, College of Agriculture, Engineering and Science, Westville Campus, University of KwaZulu-Natal, Durban 4000, South Africa.
| | - Kanike Raghavendra Kumar
- Discipline of Physics, School of Chemistry and Physics, College of Agriculture, Engineering and Science, Westville Campus, University of KwaZulu-Natal, Durban 4000, South Africa; Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, China.
| | - Venkataraman Sivakumar
- Discipline of Physics, School of Chemistry and Physics, College of Agriculture, Engineering and Science, Westville Campus, University of KwaZulu-Natal, Durban 4000, South Africa
| | - Derek Griffith
- Optronic Sensor Systems, Council for Scientific and Industrial Research (CSIR)-DPSS, Pretoria 0001, South Africa
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Duflot V, Royer P, Chazette P, Baray JL, Courcoux Y, Delmas R. Marine and biomass burning aerosols in the southern Indian Ocean: Retrieval of aerosol optical properties from shipborne lidar and Sun photometer measurements. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jd015839] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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8
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Mishchuk NA, Goncharuk VV. Generation and dynamics of aerosols over water surface. J WATER CHEM TECHNO+ 2011. [DOI: 10.3103/s1063455x11020020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Twohy CH, Coakley JA, Tahnk WR. Effect of changes in relative humidity on aerosol scattering near clouds. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd010991] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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10
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Rajeev K, Parameswaran K, Nair SK, Meenu S. Observational evidence for the radiative impact of Indonesian smoke in modulating the sea surface temperature of the equatorial Indian Ocean. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009611] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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11
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Kedia S, Ramachandran S. Features of aerosol optical depths over the Bay of Bengal and the Arabian Sea during premonsoon season: Variabilities and anthropogenic influence. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009070] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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12
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Ramanathan V, Li F, Ramana MV, Praveen PS, Kim D, Corrigan CE, Nguyen H, Stone EA, Schauer JJ, Carmichael GR, Adhikary B, Yoon SC. Atmospheric brown clouds: Hemispherical and regional variations in long-range transport, absorption, and radiative forcing. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd008124] [Citation(s) in RCA: 342] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Wang SH, Lin NH, Chou MD, Woo JH. Estimate of radiative forcing of Asian biomass-burning aerosols during the period of TRACE-P. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd007564] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sheng-Hsiang Wang
- Department of Atmospheric Sciences; National Central University; Chung-Li Taiwan
| | - Neng-Huei Lin
- Department of Atmospheric Sciences; National Central University; Chung-Li Taiwan
| | - Ming-Dah Chou
- Department of Atmospheric Sciences; National Taiwan University; Taipei Taiwan
| | - Jung-Hun Woo
- Northeast States for Coordinated Air Use Management; Boston MA USA
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Niranjan K, Sreekanth V, Madhavan BL, Krishna Moorthy K. Wintertime aerosol characteristics at a north Indian site Kharagpur in the Indo-Gangetic plains located at the outflow region into Bay of Bengal. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2006jd007635] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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15
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Ramana MV, Ramanathan V. Abrupt transition from natural to anthropogenic aerosol radiative forcing: Observations at the ABC-Maldives Climate Observatory. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2006jd007063] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Saha A, Moorthy KK, Niranjan K. Interannual Variations of Aerosol Optical Depth over Coastal India: Relation to Synoptic Meteorology. ACTA ACUST UNITED AC 2005. [DOI: 10.1175/jam2256.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
Interannual variations in spectral aerosol optical depths (AOD) were examined using the data obtained from a chain of ground-based multiwavelength solar radiometers from various locations of the Indian peninsula during the dry winter season (January–March) of 1996–2001. All of the stations revealed significant interannual variations, even though the spatial pattern of the variations differed over the years. These interannual variations were found to be significantly influenced by the extent of the southward excursion of the intertropical convergence zone (ITCZ). The years in which the southward excursion of the ITCZ was less (i.e., the years when the wintertime ITCZ was closer to the equator) showed higher AODs than the years in which the ITCZ moved far southward. The spatial variation was found to be influenced by large-scale vertical descent of an air mass over peninsular India, the Arabian Sea, the Indian Ocean, and the Bay of Bengal.
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Affiliation(s)
- Auromeet Saha
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, India
| | - K. Krishna Moorthy
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, India
| | - K. Niranjan
- Department of Physics, Andhra University, Visakhapatnam, India
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Chand D, Lal S, Naja M. Variations of ozone in the marine boundary layer over the Arabian Sea and the Indian Ocean during the 1998 and 1999 INDOEX campaigns. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2001jd001589] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Duli Chand
- Physical Research Laboratory Ahmedabad India
| | - Shyam Lal
- Physical Research Laboratory Ahmedabad India
| | - Manish Naja
- Physical Research Laboratory Ahmedabad India
- Now at Frontier Research System for Global Change, Yokohama, Japan
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18
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Ramachandran S, Jayaraman A. Premonsoon aerosol mass loadings and size distributions over the Arabian Sea and the tropical Indian Ocean. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2002jd002386] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- S. Ramachandran
- Space and Atmospheric Sciences Division Physical Research Laboratory Ahmedabad India
| | - A. Jayaraman
- Space and Atmospheric Sciences Division Physical Research Laboratory Ahmedabad India
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19
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Collins WD. Simulation of aerosol distributions and radiative forcing for INDOEX: Regional climate impacts. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2000jd000032] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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20
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Li F. Winter to summer monsoon variation of aerosol optical depth over the tropical Indian Ocean. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2001jd000949] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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21
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Tahnk WR. Aerosol optical depth and direct radiative forcing for INDOEX derived from AVHRR: Observations, January–March 1996–2000. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2000jd000183] [Citation(s) in RCA: 23] [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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22
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Coakley JA. Aerosol optical depths and direct radiative forcing for INDOEX derived from AVHRR: Theory. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2000jd000182] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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23
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Welton EJ. Measurements of aerosol vertical profiles and optical properties during INDOEX 1999 using micropulse lidars. ACTA ACUST UNITED AC 2002. [DOI: 10.1029/2000jd000038] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Ramanathan V, Crutzen PJ, Kiehl JT, Rosenfeld D. Aerosols, climate, and the hydrological cycle. Science 2001; 294:2119-24. [PMID: 11739947 DOI: 10.1126/science.1064034] [Citation(s) in RCA: 765] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Human activities are releasing tiny particles (aerosols) into the atmosphere. These human-made aerosols enhance scattering and absorption of solar radiation. They also produce brighter clouds that are less efficient at releasing precipitation. These in turn lead to large reductions in the amount of solar irradiance reaching Earth's surface, a corresponding increase in solar heating of the atmosphere, changes in the atmospheric temperature structure, suppression of rainfall, and less efficient removal of pollutants. These aerosol effects can lead to a weaker hydrological cycle, which connects directly to availability and quality of fresh water, a major environmental issue of the 21st century.
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Affiliation(s)
- V Ramanathan
- Scripps Institution of Oceanography, University of California at San Diego, CA 92093, USA.
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25
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Eck TF, Holben BN, Dubovik O, Smirnov A, Slutsker I, Lobert JM, Ramanathan V. Column-integrated aerosol optical properties over the Maldives during the northeast monsoon for 1998-2000. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2001jd000786] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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26
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Müller D, Franke K, Wagner F, Althausen D, Ansmann A, Heintzenberg J. Vertical profiling of optical and physical particle properties over the tropical Indian Ocean with six-wavelength lidar: 1. Seasonal cycle. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000jd900784] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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27
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Müller D, Franke K, Wagner F, Althausen D, Ansmann A, Heintzenberg J, Verver G. Vertical profiling of optical and physical particle properties over the tropical Indian Ocean with six-wavelength lidar: 2. Case studies. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000jd900785] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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28
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Ramanathan V, Crutzen PJ, Lelieveld J, Mitra AP, Althausen D, Anderson J, Andreae MO, Cantrell W, Cass GR, Chung CE, Clarke AD, Coakley JA, Collins WD, Conant WC, Dulac F, Heintzenberg J, Heymsfield AJ, Holben B, Howell S, Hudson J, Jayaraman A, Kiehl JT, Krishnamurti TN, Lubin D, McFarquhar G, Novakov T, Ogren JA, Podgorny IA, Prather K, Priestley K, Prospero JM, Quinn PK, Rajeev K, Rasch P, Rupert S, Sadourny R, Satheesh SK, Shaw GE, Sheridan P, Valero FPJ. Indian Ocean Experiment: An integrated analysis of the climate forcing and effects of the great Indo-Asian haze. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2001jd900133] [Citation(s) in RCA: 1054] [Impact Index Per Article: 45.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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29
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Rajeev K, Ramanathan V. Direct observations of clear-sky aerosol radiative forcing from space during the Indian Ocean Experiment. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000jd900723] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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30
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Hartley WS, Hobbs PV. An aerosol model and aerosol-induced changes in the clear-sky albedo off the east coast of the United States. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2001jd900025] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Collins WD, Rasch PJ, Eaton BE, Khattatov BV, Lamarque JF, Zender CS. Simulating aerosols using a chemical transport model with assimilation of satellite aerosol retrievals: Methodology for INDOEX. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000jd900507] [Citation(s) in RCA: 264] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Large differences in tropical aerosol forcing at the top of the atmosphere and Earth's surface. Nature 2000; 405:60-3. [PMID: 10811216 DOI: 10.1038/35011039] [Citation(s) in RCA: 167] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The effect of radiative forcing by anthropogenic aerosols is one of the largest sources of uncertainty in climate predictions. Direct observations of the forcing are therefore needed, particularly for the poorly understood tropical aerosols. Here we present an observational method for quantifying aerosol forcing to within +/-5 per cent. We use calibrated satellite radiation measurements and five independent surface radiometers to quantify the aerosol forcing simultaneously at the Earth's surface and the top of the atmosphere over the tropical northern Indian Ocean. In winter, this region is covered by anthropogenic aerosols of sulphate, nitrate, organics, soot and fly ash from the south Asian continent. Accordingly, mean clear-sky solar radiative heating for the winters of 1998 and 1999 decreased at the ocean surface by 12 to 30 Wm(-2), but only by 4 to 10 Wm(-2) at the top of the atmosphere. This threefold difference (due largely to solar absorption by soot) and the large magnitude of the observed surface forcing both imply that tropical aerosols might slow down the hydrological cycle.
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