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Chand K, Kuniyal JC, Kanga S, Guleria RP, Meraj G, Kumar P, Farooq M, Singh SK, Nathawat MS, Sahu N, Kumar R. Aerosol Characteristics and Their Impact on the Himalayan Energy Budget. Sustainability 2022; 14:179. [DOI: 10.3390/su14010179] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The extensive work on the increasing burden of aerosols and resultant climate implications shows a matter of great concern. In this study, we investigate the aerosol optical depth (AOD) variations in the Indian Himalayan Region (IHR) between its plains and alpine regions and the corresponding consequences on the energy balance on the Himalayan glaciers. For this purpose, AOD data from Moderate Resolution Imaging Spectroradiometer (MODIS, MOD-L3), Aerosol Robotic Network (AERONET), India, and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) were analyzed. Aerosol radiative forcing (ARF) was assessed using the atmospheric radiation transfer model (RTM) integrated into AERONET inversion code based on the Discrete Ordinate Radiative Transfer (DISORT) module. Further, air mass trajectory over the entire IHR was analyzed using a hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. We estimated that between 2001 and 2015, the monthly average ARF at the surface (ARFSFC), top of the atmosphere (ARFTOA), and atmosphere (ARFATM) were −89.6 ± 18.6 Wm−2, −25.2 ± 6.8 Wm−2, and +64.4 ± 16.5 Wm−2, respectively. We observed that during dust aerosol transport days, the ARFSFC and TOA changed by −112.2 and −40.7 Wm−2, respectively, compared with low aerosol loading days, thereby accounting for the decrease in the solar radiation by 207% reaching the surface. This substantial decrease in the solar radiation reaching the Earth’s surface increases the heating rate in the atmosphere by 3.1-fold, thereby acting as an additional forcing factor for accelerated melting of the snow and glacier resources of the IHR.
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Li C, Yan F, Kang S, Yan C, Hu Z, Chen P, Gao S, Zhang C, He C, Kaspari S, Stubbins A. Carbonaceous matter in the atmosphere and glaciers of the Himalayas and the Tibetan plateau: An investigative review. Environ Int 2021; 146:106281. [PMID: 33395932 DOI: 10.1016/j.envint.2020.106281] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 11/05/2020] [Accepted: 11/09/2020] [Indexed: 06/12/2023]
Abstract
Carbonaceous matter, including organic carbon (OC) and black carbon (BC), is an important climate forcing agent and contributes to glacier retreat in the Himalayas and the Tibetan Plateau (HTP). The HTP - the so-called "Third Pole" - contains the most extensive glacial area outside of the polar regions. Considerable research on carbonaceous matter in the HTP has been conducted, although this research has been challenging due to the complex terrain and strong spatiotemporal heterogeneity of carbonaceous matter in the HTP. A comprehensive investigation of published atmospheric and snow data for HTP carbonaceous matter concentration, deposition and light absorption is presented, including how these factors vary with time and other parameters. Carbonaceous matter concentrations in the atmosphere and glaciers of the HTP are found to be low. Analysis of water-insoluable organic carbon and BC from snowpits reveals that concentrations of OC and BC in the atmosphere and glacier samples in arid regions of the HTP may be overestimated due to contributions from inorganic carbon in mineral dust. Due to the remote nature of the HTP, carbonaceous matter found in the HTP has generally been transported from outside the HTP (e.g., South Asia), although local HTP emissions may also be important at some sites. This review provides essential data and a synthesis of current thinking for studies on atmospheric transport modeling and radiative forcing of carbonaceous matter in the HTP.
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Affiliation(s)
- Chaoliu Li
- CAS Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China.
| | - Fangping Yan
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; UT School of Engineering Science, Lappeenranta University of Technology, P.O. Box 20, 53851 Lappeenranta, Finland
| | - Shichang Kang
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; CAS Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Caiqing Yan
- Environment Research Institute, Shandong University, Qingdao 266237, China
| | - Zhaofu Hu
- 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
| | - Pengfei Chen
- State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Shaopeng Gao
- CAS Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Chao Zhang
- CAS Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Cenlin He
- Research Applications Laboratory, National Center for Atmospheric Research, Boulder, CO 80301, USA
| | - Susan Kaspari
- Department of Geological Sciences, Central Washington University, Ellensburg, WA 98926, USA
| | - Aron Stubbins
- Departments of Marine and Environmental Science, Chemistry and Chemical Biology, and Civil and Environmental Engineering, Northeastern University, Boston, MA 02115, USA
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Dumka UC, Ningombam SS, Kaskaoutis DG, Madhavan BL, Song HJ, Angchuk D, Jorphail S. Long-term (2008-2018) aerosol properties and radiative effect at high-altitude sites over western trans-Himalayas. Sci Total Environ 2020; 734:139354. [PMID: 32470663 DOI: 10.1016/j.scitotenv.2020.139354] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 05/08/2020] [Accepted: 05/09/2020] [Indexed: 06/11/2023]
Abstract
Analysis of the climatology of aerosol properties is performed over Hanle (4500 m) and Merak (4310 m), two remote-background sites in the western trans-Himalayas, based on eleven years (2008-2018) of sun/sky radiometer (POM-01, Prede) measurements. The two sites present very similar atmospheric conditions and aerosol properties allowing us to examine them as continuous single-data series. The annual average aerosol optical depth at 500 nm (AOD500) is 0.04 ± 0.03, associated with an Ångström exponent (AE440-870) of 0.58 ± 0.35 and a single scattering albedo (SSA500) of 0.95 ± 0.05. AOD500 exhibits higher values in May (~0.07) and lower in winter (~0.03), while AE400-870 minimizes in spring, indicating influence by coarse-mode dust aerosols, either emitted regionally or long-range transported. The de-convolution of AOD500 into fine and coarse modes justifies the aerosol seasonality and sources, while the marginal diurnal variation in all aerosol properties reveals a weak influence from local sources, except for some few aerosol episodes. The aerosol-volume size distribution presents a mode value at ~10 μm with secondary peaks at accumulation (~ 2 μm) and fine modes (~0.03 μm) and low variability between the seasons. A classification of the aerosol types based on the fine-mode fraction (FMF) vs. SSA500 relationship reveals the dominance of aerosols in the FMF range of 0.4-0.6, characterized as mixed (39%), followed by fine aerosols with high scattering efficiency (26%), while particles related to dust contribute ~21%, with low fractions of fine-absorbing aerosols (~13%). The aerosol radiative forcing (ARF) estimates reveal a small cooling effect at the top of the atmosphere (-1.3 Wm-2), while at the surface, the ARF ranges from -2 Wm-2 to -6 Wm-2 on monthly basis. The monthly-mean atmospheric radiative forcing (~1 to 4 Wm-2) leads to heating rates of 0.04 to 0.13 K day-1. These ARF values are higher than the global averages and may cause climate implications over the trans-Himalayan region.
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Affiliation(s)
- U C Dumka
- Aryabhatta Research Institute of observational Sciences, Nainital 263001, India.
| | | | - D G Kaskaoutis
- Institute for Environmental Research and Sustainable Development, National Observatory of Athens, Palaia Penteli, 15236 Athens, Greece.
| | - B L Madhavan
- National Atmospheric Research Laboratory (NARL), Department of Space, Gadanki 517112, India
| | - H-J Song
- National Institute of Meteorological Sciences, Seogwipo, Jeju, South Korea
| | - Dorje Angchuk
- Indian Astronomical Observatory, Indian Institute of Astrophysics, Skara, Leh-Ladakh, 194101, India
| | - Sonam Jorphail
- Indian Astronomical Observatory, Indian Institute of Astrophysics, Skara, Leh-Ladakh, 194101, India
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Zeb B, Alam K, Sorooshian A, Chishtie F, Ahmad I, Bibi H. Temporal characteristics of aerosol optical properties over the glacier region of northern Pakistan. J Atmos Sol Terr Phys 2019; 186:35-46. [PMID: 33911973 PMCID: PMC8078013 DOI: 10.1016/j.jastp.2019.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Glacier melting due to light-absorbing aerosol has become a growing issue in recent decades. The emphasis of this study is to examine aerosol loadings over the high mountain glacier region of northern Pakistan between 2004 and 2016, with sources including local emissions and long-range transported pollution. Optical properties of aerosols were seasonally analyzed over the glacier region (35-36.5°N; 74.5-77.5°E) along with three selected sites (Gilgit, Skardu, and Diamar) based on the Ozone Monitoring Instrument (OMI). The aerosol sub-type profile was analyzed with Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to understand the origin of air masses arriving in the study region. The highest values of aerosol optical depth (AOD) and single scattering albedo (SSA) occurred during spring, whereas aerosol index (AI) and absorption AOD (AAOD) exhibited maximum values in winter and summer, respectively. The minimum values of AOD, AI, AAOD, and SSA occurred in winter, autumn, winter, and autumn, respectively. The results revealed that in spring and summer the prominent aerosols were dust, whereas, in autumn and winter, anthropogenic aerosols were prominent. Trend analysis showed that AI, AOD, and AAOD increased at the rate of 0.005, 0.006, and 0.0001 yr-1, respectively, while SSA decreased at the rate of 0.0002 yr-1. This is suggestive of the enhancement in aerosol types over the region with time that accelerates melting of ice. CALIPSO data indicate that the regional aerosol was mostly comprised of sub-types categorized as dust, polluted dust, smoke, and clean continental. The types of aerosols defined by OMI were in good agreement with CALIPSO retrievals. Analysis of the National Oceanic and Atmospheric Administration Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model revealed that air parcels arriving at the glacier region stemmed from different source sites.
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Affiliation(s)
- Bahadar Zeb
- Department of Physics, University of Malakand, Khyber Pakhtunkhwa, Pakistan
- Department of Mathematics, Shaheed Benazir Bhutto University, Sheringal, Dir Upper, Khyber Pakhtunkhwa, Pakistan
| | - Khan Alam
- Department of Physics, University of Peshawar, Khyber Pakhtunkhwa, Pakistan
- Corresponding author. (K. Alam)
| | - Armin Sorooshian
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
- Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - Farrukh Chishtie
- SERVIR-Mekong, Asian Disaster Preparedness Centre (ADPC), Bangkok, Thailand
| | - Ifthikhar Ahmad
- Department of Physics, University of Malakand, Khyber Pakhtunkhwa, Pakistan
| | - Humera Bibi
- Department of Physics, University of Peshawar, Khyber Pakhtunkhwa, Pakistan
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Sarkar C, Roy A, Chatterjee A, Ghosh SK, Raha S. Factors controlling the long-term (2009-2015) trend of PM 2.5 and black carbon aerosols at eastern Himalaya, India. Sci Total Environ 2019; 656:280-296. [PMID: 30513422 DOI: 10.1016/j.scitotenv.2018.11.367] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 11/19/2018] [Accepted: 11/24/2018] [Indexed: 06/09/2023]
Abstract
A first-ever long-term (2009-2015) study on the fine particulate matter (PM2.5) and black carbon (BC) aerosol were conducted over Himalaya in order to investigate the characteristics, temporal variations and the important factors regulating the long-term trend. The study was conducted over a high altitude station, Darjeeling (27°01'N, 88°15'E, 2200 m asl) representing a typical high altitude urban atmosphere at eastern Himalaya in India. The average concentrations of PM2.5 and BC over a period of seven years were 25.2 ± 5.6 μg m-3 (ranging between 2.2 and 220.4 μg m-3) and 3.4 ± 0.7 μg m-3 (0.4 to 15.6 μg m-3) respectively. We observed decreasing trends in both PM2.5 (49% at a rate of 170 ng m-3 month-1) and BC (34% at the rate of 20 ng m-3 month-1) mass concentration over this region from 2009 to 2015. We extensively studied the impact of micrometeorological parameters on the long-term trend in PM2.5 and BC through the correlation analysis. The significant changes in boundary layer dynamics over this region played a major role in the decreasing trend of aerosols. The concentration weighted trajectory analysis revealed that the important contributory long-distant source regions for PM2.5 and BC over eastern Himalaya were Indo Gangetic Plane and Nepal. The contributions from these regions were found to be decreased significantly from 2009 to 2015. Investigations on the fire counts associated with the forest fire, and open burning activities through the satellite observations revealed that the decreasing trend in PM2.5 and BC over eastern Himalaya is well correlated to the decreasing trend in the fire counts over IGP and Nepal. We also explored that the changes and up gradation of the domestic fuel at the Indo Gangetic Plane regions in recent years not only improved the regional air quality but also affected the atmospheric environment over the eastern part of Himalaya.
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Affiliation(s)
- Chirantan Sarkar
- Environmental Science Section, Bose Institute, P 1/12 CIT Scheme VII-M, Kolkata 700054, India
| | - Arindam Roy
- Environmental Science Section, Bose Institute, P 1/12 CIT Scheme VII-M, Kolkata 700054, India
| | - Abhijit Chatterjee
- Environmental Science Section, Bose Institute, P 1/12 CIT Scheme VII-M, Kolkata 700054, India; National Facility on Astroparticle Physics and Space Science, Bose Institute, 16, A.J.C. Bose Road, Darjeeling 734101, India.
| | - Sanjay K Ghosh
- Environmental Science Section, Bose Institute, P 1/12 CIT Scheme VII-M, Kolkata 700054, India; National Facility on Astroparticle Physics and Space Science, Bose Institute, 16, A.J.C. Bose Road, Darjeeling 734101, India; National Center for Astroparticle Physics and Space Science, Block-EN, Sector-V, Salt Lake, Kolkata 700091, India
| | - Sibaji Raha
- National Facility on Astroparticle Physics and Space Science, Bose Institute, 16, A.J.C. Bose Road, Darjeeling 734101, India; National Center for Astroparticle Physics and Space Science, Block-EN, Sector-V, Salt Lake, Kolkata 700091, India
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Sharma D, Srivastava AK, Ram K, Singh A, Singh D. Temporal variability in aerosol characteristics and its radiative properties over Patiala, northwestern part of India: Impact of agricultural biomass burning emissions. Environ Pollut 2017; 231:1030-1041. [PMID: 28915541 DOI: 10.1016/j.envpol.2017.08.052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 08/11/2017] [Accepted: 08/12/2017] [Indexed: 06/07/2023]
Abstract
A comprehensive measurements of aerosol optical depth (AOD), particulate matter (PM) and black carbon (BC) mass concentrations have been carried out over Patiala, a semi-urban site in northwest India during October 2008 to September 2010. The measured aerosol data was incorporated in an aerosol optical model to estimate various aerosol optical parameters, which were subsequently used for radiative forcing estimation. The measured AOD at 500 nm (AOD500) shows a significant seasonal variability, with maximum value of 0.81 during post-monsoon (PoM) and minimum of 0.56 during winter season. The Ångström exponent (α) has higher values (i.e. more fine-mode fraction) during the PoM/winter periods, and lower (i.e. more coarse-mode fraction) during pre-monsoon (PrM). In contrast, turbidity coefficient (β) exhibits an opposite trend to α during the study period. BC mass concentration varies from 2.8 to 13.9 μg m-3 (mean: 6.5 ± 3.2 μg m-3) during the entire study period, with higher concentrations during PoM/winter and lower during PrM/monsoon seasons. The average single scattering albedo (SSA at 500 nm) values are 0.70, 0.72, 0.82 and 0.75 during PoM, winter, PrM and monsoon seasons, respectively. However, inter-seasonal and inter-annual variability in measured aerosol parameters are statistically insignificant at Patiala. These results suggest strong changes in emission sources, aerosol composition, meteorological parameters as well as transport of aerosols over the station. Higher values of AOD, α and BC, along with lower SSA during PoM season are attributed to agriculture biomass burning emissions over and around the station. The estimated aerosol radiative forcing within the atmosphere is positive (i.e. warming) during all the seasons with higher values (∼60 Wm-2) during PoM-08/PoM-09 and lower (∼40 Wm-2) during winter-09/PrM-10. The present study highlights the role of BC aerosols from agricultural biomass burning emissions during post-monsoon season for atmospheric warming at Patiala.
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Affiliation(s)
- D Sharma
- Department of Physics, Punjabi University, Patiala, India; Department of Physics, Arya College, Ludhiana, India
| | - A K Srivastava
- Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi, India.
| | - K Ram
- Institute of Environment & Sustainable Development, Banaras Hindu University, Varanasi, India
| | - A Singh
- Department of Physics, Punjabi University, Patiala, India
| | - D Singh
- Department of Physics, Punjabi University, Patiala, India
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Dhar P, De BK, Banik T, Gogoi MM, Babu SS, Guha A. Atmospheric aerosol radiative forcing over a semi-continental location Tripura in North-East India: Model results and ground observations. Sci Total Environ 2017; 580:499-508. [PMID: 28034546 DOI: 10.1016/j.scitotenv.2016.11.200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 11/25/2016] [Accepted: 11/27/2016] [Indexed: 06/06/2023]
Abstract
Northeast India (NEI) is located within the boundary of the great Himalayas in the north and the Bay of Bengal (BoB) in the southwest, experiences the mixed influence of the westerly dust advection from the Indian desert, anthropogenic aerosols from the highly polluted Indo-Gangetic Plains (IGP) and marine aerosols from BoB. The present study deals with the estimation and characterization of aerosol radiative forcing over a semi-continental site Tripura, which is a strategic location in the western part of NEI having close proximity to the outflow of the IGP. Continuous long term measurements of aerosol black carbon (BC) mass concentrations and columnar aerosol optical depth (AOD) are used for the estimation of aerosol radiative forcing in each monthly time scale. The study revealed that the surface forcing due to aerosols was higher during both winter and pre-monsoon seasons, having comparable values of 32W/m2 and 33.45W/m2 respectively. The atmospheric forcing was also higher during these months due to increased columnar aerosol loadings (higher AOD ~0.71) shared by abundant BC concentrations (SSA ~0.7); while atmospheric forcing decreased in monsoon due to reduced magnitude of BC (SSA ~0.94 in July) as well as columnar AOD. The top of the atmosphere (TOA) forcing is positive in pre-monsoon and monsoon months with the highest positive value of 3.78W/m2 in June 2012. The results are discussed in light of seasonal source impact and transport pathways from adjacent regions.
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Affiliation(s)
- Pranab Dhar
- Department of Physics, Tripura University, Suryamaninagar 799022, India
| | - Barin Kumar De
- Department of Physics, Tripura University, Suryamaninagar 799022, India
| | - Trisanu Banik
- Department of Physics, Tripura University, Suryamaninagar 799022, India
| | - Mukunda M Gogoi
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram 695022, India
| | - S Suresh Babu
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram 695022, India
| | - Anirban Guha
- Department of Physics, Tripura University, Suryamaninagar 799022, India.
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Bisht DS, Srivastava AK, Joshi H, Ram K, Singh N, Naja M, Srivastava MK, Tiwari S. Chemical characterization of rainwater at a high-altitude site "Nainital" in the central Himalayas, India. Environ Sci Pollut Res Int 2017; 24:3959-3969. [PMID: 27913957 DOI: 10.1007/s11356-016-8093-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 11/11/2016] [Indexed: 06/06/2023]
Abstract
The present study investigates the chemical composition of rainwater (RW) from a high-altitude site "Nainital" (1958 m above msl) in the central Himalaya region, to understand the influence of local, regional, and long-range transport of pollutants. A total of 55 (2 in pre-monsoon and 53 in monsoon) RW samples were collected during the study period (June-September 2012) and were analyzed for major anions and cations using an ion chromatograph. The pH of precipitation events ranged from 4.95 to 6.50 (average 5.6 ± 0.3) was observed during the monsoon period (near to the acidic), whereas during the pre-monsoon, the pH was 6.25 ± 0.49 (alkaline) over the study region; it is due the mixture of anthropogenic as well as the natural chemical constituents. The average ionic concentration (sum of measured chemical constituents) was ∼3 times higher during the pre-monsoon (986 ± 101 μeq/1) compared to that in the monsoon season (373 ± 37 μeq/1). This is mainly due to the presence of more natural aerosols in the pre-monsoon season which is also reflected in the pH of rainwater (average 6.25 ± 0.50) as well as ionic concentration. The chemical composition suggests that Ca2+ was the major contributor (34%) among cations, followed by Na+ (10%), K+ (8%), and Mg2+ (9%), whereas Cl-, NO3-, and SO42- contributed ∼13, 11, and 9%, respectively, among anions. The average ratio of acidic species (SO42-/NO3-) is 1.56, suggesting 61 and 39% contribution of SO42- and NO3-, respectively, which is very close to the estimated contribution of H2SO4 (60-70%) and HNO3 (30-40%) in the precipitation samples. Neutralization factors for Ca2+, Mg2+, and NH4+ in RW at Nainital are 4.94, 1.21, and 0.37, respectively, indicating their crucial role in neutralization of acidic species. The non-sea-salt (NSS) contribution to total Ca2+, K+, and Mg2+ is estimated to be ∼98, 97, and 74%, respectively, suggesting the dominance of crustal sources for cations. In contrast, the NSS contribution to the total Cl- and SO42- is 16 and 69% indicating their anthropogenic origin, respectively. Principle component analysis also suggests that the first factor (i.e., natural sources, mainly dust, and sea-salts) accounts for ∼33% variance, whereas the second factor (i.e., fossil fuel and biomass burning) accounts for ∼18% variance of the measured ionic composition. The remaining contributions are attributed to the mixed emission sources and transport of pollutants from Indo-Gangetic Plain (IGP) and western parts of India. The results of the present study reveal a significant contribution of crustal and anthropogenic sources in the RW and neutralization processes in the central Himalaya.
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Affiliation(s)
- Deewan Singh Bisht
- Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi, 110060, India.
| | - A K Srivastava
- Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi, 110060, India
| | - H Joshi
- Aryabhatta Research Institute for Observational Science, Manora Peak, Nainital, India
| | - K Ram
- Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, India
| | - N Singh
- Aryabhatta Research Institute for Observational Science, Manora Peak, Nainital, India
| | - M Naja
- Aryabhatta Research Institute for Observational Science, Manora Peak, Nainital, India
| | - M K Srivastava
- Department of Geophysics, Banaras Hindu University, Varanasi, India
| | - S Tiwari
- Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi, 110060, India
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Satheesh SK, Suresh Babu S, Padmakumari B, Pandithurai G, Soni VK. Variability of Atmospheric Aerosols Over India. Springer Geology 2017. [DOI: 10.1007/978-981-10-2531-0_13] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Hegde P, Kawamura K, Joshi H, Naja M. Organic and inorganic components of aerosols over the central Himalayas: winter and summer variations in stable carbon and nitrogen isotopic composition. Environ Sci Pollut Res Int 2016; 23:6102-6118. [PMID: 26490923 DOI: 10.1007/s11356-015-5530-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 10/04/2015] [Indexed: 06/05/2023]
Abstract
The aerosol samples were collected from a high elevation mountain site, Nainital, in India (1958 m asl) during September 2006 to June 2007 and were analyzed for water-soluble inorganic species, total carbon, nitrogen, and their isotopic composition (δ(13)C and δ(15)N, respectively). The chemical and isotopic composition of aerosols revealed significant anthropogenic influence over this remote free-troposphere site. The amount of total carbon and nitrogen and their isotopic composition suggest a considerable contribution of biomass burning to the aerosols during winter. On the other hand, fossil fuel combustion sources are found to be dominant during summer. The carbon aerosol in winter is characterized by greater isotope ratios (av. -24.0‰), mostly originated from biomass burning of C4 plants. On the contrary, the aerosols in summer showed smaller δ(13)C values (-26.0‰), indicating that they are originated from vascular plants (mostly of C3 plants). The secondary ions (i.e., SO4 (2-), NH4 (+), and NO3 (-)) were abundant due to the atmospheric reactions during long-range transport in both seasons. The water-soluble organic and inorganic compositions revealed that they are aged in winter but comparatively fresh in summer. This study validates that the pollutants generated from far distant sources could reach high altitudes over the Himalayan region under favorable meteorological conditions.
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Affiliation(s)
- Prashant Hegde
- Space Physics Laboratory, Vikram Sarabhai Space Centre, Trivandrum, India.
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan.
| | - Kimitaka Kawamura
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - H Joshi
- Aryabhatta Research Institute of Observational Sciences, Nainital, India
| | - M Naja
- Aryabhatta Research Institute of Observational Sciences, Nainital, India
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Ram K, Sarin MM. Atmospheric carbonaceous aerosols from Indo-Gangetic Plain and Central Himalaya: impact of anthropogenic sources. J Environ Manage 2015; 148:153-163. [PMID: 25199599 DOI: 10.1016/j.jenvman.2014.08.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 07/03/2014] [Accepted: 08/15/2014] [Indexed: 06/03/2023]
Abstract
In the present-day scenario of growing anthropogenic activities, carbonaceous aerosols contribute significantly (∼20-70%) to the total atmospheric particulate matter mass and, thus, have immense potential to influence the Earth's radiation budget and climate on a regional to global scale. In addition, formation of secondary organic aerosols is being increasingly recognized as an important process in contributing to the air-pollution and poor visibility over urban regions. It is, thus, essential to study atmospheric concentrations of carbonaceous species (EC, OC and WSOC), their mixing state and absorption properties on a regional scale. This paper presents the comprehensive data on emission sources, chemical characteristics and optical properties of carbonaceous aerosols from selected urban sites in the Indo-Gangetic Plain (IGP) and from a high-altitude location in the central Himalaya. The mass concentrations of OC, EC and WSOC exhibit large spatio-temporal variability in the IGP. This is attributed to seasonally varying emissions from post-harvest agricultural-waste burning, their source strength, boundary layer dynamics and secondary aerosol formation. The high concentrations of OC and SO4(2-), and their characteristic high mass scattering efficiency, contribute significantly to the aerosol optical depth and scattering coefficient. This has implications to the assessment of single scattering albedo and aerosol radiative forcing on a regional scale.
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Affiliation(s)
- Kirpa Ram
- Physical Research Laboratory, Ahmedabad 380009, India; Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi 221 005, India.
| | - M M Sarin
- Physical Research Laboratory, Ahmedabad 380009, India.
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Srivastava AK, Ram K, Singh S, Kumar S, Tiwari S. Aerosol optical properties and radiative effects over Manora Peak in the Himalayan foothills: seasonal variability and role of transported aerosols. Sci Total Environ 2015; 502:287-295. [PMID: 25261819 DOI: 10.1016/j.scitotenv.2014.09.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 07/03/2014] [Accepted: 09/07/2014] [Indexed: 06/03/2023]
Abstract
The higher altitude regions of Himalayas and Tibetan Plateau are influenced by the dust and black carbon (BC) aerosols from the emissions and long-range transport from the adjoining areas. In this study, we present impacts of advection of polluted air masses of natural and anthropogenic emissions, on aerosol optical and radiative properties at Manora Peak (~2000 m amsl) in central Himalaya over a period of more than two years (February 2006-May 2008). We used the most updated and comprehensive data of chemical and optical properties available in one of the most climatically sensitive region, the Himalaya, to estimate atmospheric radiative forcing and heating rate. Aerosol optical depth (AOD) was found to vary from 0.04 to 0.45 with significantly higher values in summer mainly due to an increase in mineral dust and biomass burning aerosols due to transport. In contrast, single scattering albedo (SSA) varied from 0.74 to 0.88 with relatively lower values during summer, suggesting an increase in absorbing BC and mineral dust aerosols. As a result, a large positive atmospheric radiative forcing (about 28 ± 5 Wm(-2)) and high values of corresponding heating rate (0.80 ± 0.14 Kday(-1)) has been found during summer. During the entire observation period, radiative forcing at the top of the atmosphere varied from -2 to +14 Wm(-2) and from -3 to -50 Wm(-2) at the surface whereas atmospheric forcing was in the range of 3 to 65 Wm(-2) resulting in a heating rate of 0.1-1.8 Kday(-1).
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Affiliation(s)
- A K Srivastava
- Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi, India
| | - K Ram
- Institute of Environment & Sustainable Development, Banaras Hindu University, Varanasi, India
| | - Sachchidanand Singh
- Radio & Atmospheric Sciences Division, CSIR-National Physical Laboratory, New Delhi, India.
| | - Sanjeev Kumar
- Radio & Atmospheric Sciences Division, CSIR-National Physical Laboratory, New Delhi, India
| | - S Tiwari
- Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi, India
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Menon HB, Shirodkar S, Kedia S, S R, Babu S, Moorthy KK. Temporal variation of aerosol optical depth and associated shortwave radiative forcing over a coastal site along the west coast of India. Sci Total Environ 2014; 468-469:83-92. [PMID: 24012896 DOI: 10.1016/j.scitotenv.2013.08.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 06/17/2013] [Accepted: 08/06/2013] [Indexed: 06/02/2023]
Abstract
Optical characterization of aerosol was performed by assessing the columnar aerosol optical depth (AOD) and angstrom wavelength exponent (α) using data from the Microtops II Sunphotometer. The data were collected on cloud free days over Goa, a coastal site along the west coast of India, from January to December 2008. Along with the composite aerosol, the black carbon (BC) mass concentration from the Aethalometer was also analyzed. The AOD0.500 μm and angstrom wavelength exponent (α) were in the range of 0.26 to 0.7 and 0.52 to 1.33, respectively, indicative of a significant seasonal shift in aerosol characteristics during the study period. The monthly mean AOD0.500 μm exhibited a bi-modal distribution, with a primary peak in April (0.7) and a secondary peak in October (0.54), whereas the minimum of 0.26 was observed in May. The monthly mean BC mass concentration varied between 0.31 μg/m(3) and 4.5 μg/m(3), and the single scattering albedo (SSA), estimated using the OPAC model, ranged from 0.87 to 0.97. Modeled aerosol optical properties were used to estimate the direct aerosol shortwave radiative forcing (DASRF) in the wavelength range 0.25 μm4.0 μm. The monthly mean forcing at the surface, at the top of the atmosphere (TOA) and in the atmosphere varied between -14.1 Wm(-2) and -35.6 Wm(-2), -6.7 Wm(-2) and -13.4 Wm(-2) and 5.5 Wm(-2) to 22.5 Wm(-2), respectively. These results indicate that the annual SSA cycle in the atmosphere is regulated by BC (absorbing aerosol), resulting in a positive forcing; however, the surface forcing was governed by the natural aerosol scattering, which yielded a negative forcing. These two conditions neutralized, resulting in a negative forcing at the TOA that remains nearly constant throughout the year.
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Affiliation(s)
- Harilal B Menon
- Department of Marine Sciences, Goa University, Taleigao Plateau, Panjim, Goa 403602, India.
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Verma S, Payra S, Gautam R, Prakash D, Soni M, Holben B, Bell S. Dust events and their influence on aerosol optical properties over Jaipur in Northwestern India. Environ Monit Assess 2013; 185:7327-42. [PMID: 23397540 DOI: 10.1007/s10661-013-3103-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Accepted: 01/16/2013] [Indexed: 05/04/2023]
Abstract
In this study, we systematically document the link between dust episodes and local scale regional aerosol optical properties over Jaipur located in the vicinity of Thar Desert in the northwestern state of Rajasthan. The seasonal variation of AOT(500 nm) (aerosol optical thickness) shows high values (0.51 ± 0.18) during pre-monsoon (dust dominant) season while low values (0.36 ± 0.14) are exhibited during winter. The Ångström wavelength exponent has been found to exhibit low value (<0.25) indicating relative dominance of coarse-mode particles during pre-monsoon season. The AOT increased from 0.36 (Aprilmean) to 0.575 (May-June(mean)). Consequently, volume concentration range increases from April through May-June followed by a sharp decline in July during the first active phase of the monsoon. Significantly high dust storms were observed over Jaipur as indicated by high values of single scattering albedo (SSA(440 nm) = 0.89, SSA(675 nm) = 0.95, SSA870 nm = 0.97, SSA(1,020 nm) = 0.976) than the previously reported values over IGP region sites. The larger SSA values (more scattering aerosol), especially at longer wavelengths, is due to the abundant dust loading, and is attributed to the measurement site's proximity to the Thar Desert. The mean and standard deviation in SSA and asymmetry parameter during pre-monsoon season over Jaipur is 0.938 ± 0.023 and 0.712 ± 0.017 at 675 nm wavelength, respectively. Back-trajectory air mass simulations suggest Thar Desert in northwestern India as the primary source of high aerosols dust loading over Jaipur region as well as contribution by long-range transport from the Arabian Peninsula and Middle East gulf regions, during pre-monsoon season.
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Affiliation(s)
- Sunita Verma
- Centre of Excellence in Climatology, Birla Institute of Technology Mesra, Extension Centre Jaipur, Jaipur, 302017 Rajasthan, India.
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Zhao S, Ming J, Sun J, Xiao C. Observation of carbonaceous aerosols during 2006-2009 in Nyainqêntanglha Mountains and the implications for glaciers. Environ Sci Pollut Res Int 2013; 20:5827-38. [PMID: 23479337 DOI: 10.1007/s11356-013-1548-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 02/04/2013] [Indexed: 05/15/2023]
Abstract
Atmospheric carbonaceous aerosols were sampled discontinuously from July 2006 to December 2009 at Nam Co Comprehensive Observation and Research Station (NCOS) in the central Tibetan Plateau (TP). The mean daily concentration of carbonaceous aerosols increased from 268 to 330 ng m(-3), and pollution episodes could significantly increase the mean level of carbonaceous aerosols in the total mass concentration. Organic carbon was the main component of carbonaceous aerosols at NCOS, and black carbon (BC) accounted for 5.8 %. Seven-day air masses backward trajectories calculated by the Hybrid Single-Particle Lagrangian Integrated Trajectory model and the aerosol optical depth distribution in the TP and South Asia both suggested that atmospheric pollutants emitted from Northern India and South Asia could penetrate into central TP by southwest winds. Due to the seasonal variations of emission sources and regional atmospheric conditions, calculated BC deposition flux in the nonmonsoon season was higher than that in the monsoon season. Increased BC concentration in snowpack in winter from 2007 to 2009 indicated that the atmospheric environment in central TP became more polluted and the influences from human activities have strengthened. Pollution episodes could significantly increase BC concentrations in the snowpack on a seasonal scale, which would furthermore affect the surface albedo.
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Affiliation(s)
- Shuyu Zhao
- State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou, Gansu, 730000, China
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Panwar TS, Hooda RK, Lihavainen H, Hyvarinen AP, Sharma VP, Viisanen Y. Atmospheric aerosols at a regional background Himalayan site--Mukteshwar, India. Environ Monit Assess 2013; 185:4753-4764. [PMID: 23160718 DOI: 10.1007/s10661-012-2902-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 09/24/2012] [Indexed: 06/01/2023]
Abstract
Continuous aerosol measurements were made at a regional background station (Mukteshwar) located in a rural Himalayan mountain terrain from December 2005 to December 2008 for a period of 3 years. The average concentrations of particulate matter less than or equal to 10 μm (PM₁₀), particulate matter less than or equal to 2.5 μm (PM₂.₅) and black carbon (BC) are 46.0, 26.6 and 0.85 μg/m(3) during the study period. Majority of the PM₁₀ values lie below 100 μg/m(3) while majority of the PM₂.₅ values lie below 30 μg/m(3). It is further seen that during the monsoon months, especially July and August, the average values are comparatively low. It is also noted that the PM₂.₅/PM₁₀ ratios between 0.50 and 0.75 have the maximum frequency distribution in the data set. Furthermore, the monthly mean ratio of BC to PM₂.₅ mass lies between 3.0 and 7.5 % during the study period. Though the average PM₁₀ and PM₂.₅ concentrations during the study period are less than the respective Indian ambient air quality standards, however, they are still above the WHO guidelines and would have adverse health impacts. This shows that even in rural/background regions that are far away from major pollution sources or urban areas, the aerosol concentrations are significant and require long-term monitoring, source quantification and aerosol model simulations.
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Affiliation(s)
- T S Panwar
- The Energy and Resources Institute, IHC, Lodi Road, New Delhi 110003, India.
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Srivastava AK, Singh S, Tiwari S, Bisht DS. Contribution of anthropogenic aerosols in direct radiative forcing and atmospheric heating rate over Delhi in the Indo-Gangetic Basin. Environ Sci Pollut Res Int 2012; 19:1144-58. [PMID: 22006505 DOI: 10.1007/s11356-011-0633-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 09/29/2011] [Indexed: 05/15/2023]
Abstract
INTRODUCTION The present work is aimed to understand direct radiation effects due to aerosols over Delhi in the Indo-Gangetic Basin (IGB) region, using detailed chemical analysis of surface measured aerosols during the year 2007. METHODS An optically equivalent aerosol model was formulated on the basis of measured aerosol chemical compositions along with the ambient meteorological parameters to derive radiatively important aerosol optical parameters. The derived aerosol parameters were then used to estimate the aerosol direct radiative forcing at the top of the atmosphere, surface, and in the atmosphere. RESULTS The anthropogenic components measured at Delhi were found to be contributing ∼ 72% to the composite aerosol optical depth (AOD(0.5) ∼ 0.84). The estimated mean surface and atmospheric forcing for composite aerosols over Delhi were found to be about -69, -85, and -78 W m(-2) and about +78, +98, and +79 W m(-2) during the winter, summer, and post-monsoon periods, respectively. The anthropogenic aerosols contribute ∼ 90%, 53%, and 84% to the total aerosol surface forcing and ∼ 93%, 54%, and 88% to the total aerosol atmospheric forcing during the above respective periods. The mean (± SD) surface and atmospheric forcing for composite aerosols was about -79 (± 15) and +87 (± 26) W m(-2) over Delhi with respective anthropogenic contributions of ∼ 71% and 75% during the overall period of observation. CONCLUSIONS Aerosol induced large surface cooling, which was relatively higher during summer as compared to the winter suggesting an increase in dust loading over the station. The total atmospheric heating rate at Delhi averaged during the observation was found to be 2.42 ± 0.72 K day(-1), of which the anthropogenic fraction contributed as much as ∼ 73%.
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Affiliation(s)
- Atul K Srivastava
- Indian Institute of Tropical Meteorology (Branch), Prof Ramnath Vij Marg, New Delhi, India.
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Babu SS, Chaubey JP, Krishna Moorthy K, Gogoi MM, Kompalli SK, Sreekanth V, Bagare SP, Bhatt BC, Gaur VK, Prabhu TP, Singh NS. High altitude (∼4520 m amsl) measurements of black carbon aerosols over western trans-Himalayas: Seasonal heterogeneity and source apportionment. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jd016722] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kumar R, Naja M, Satheesh SK, Ojha N, Joshi H, Sarangi T, Pant P, Dumka UC, Hegde P, Venkataramani S. Influences of the springtime northern Indian biomass burning over the central Himalayas. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jd015509] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Ram K, Sarin MM, Tripathi SN. A 1 year record of carbonaceous aerosols from an urban site in the Indo-Gangetic Plain: Characterization, sources, and temporal variability. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jd014188] [Citation(s) in RCA: 172] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kirpa Ram
- Physical Research Laboratory; Ahmedabad India
| | - M. M. Sarin
- Physical Research Laboratory; Ahmedabad India
| | - S. N. Tripathi
- Department of Civil Engineering; Indian Institute of Technology; Kanpur India
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Pathak B, Kalita G, Bhuyan K, Bhuyan PK, Moorthy KK. Aerosol temporal characteristics and its impact on shortwave radiative forcing at a location in the northeast of India. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jd013462] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Gautam R, Hsu NC, Lau KM. Premonsoon aerosol characterization and radiative effects over the Indo-Gangetic Plains: Implications for regional climate warming. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2010jd013819] [Citation(s) in RCA: 163] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kumar R, Naja M, Venkataramani S, Wild O. Variations in surface ozone at Nainital: A high-altitude site in the central Himalayas. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jd013715] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Vinoj V, Satheesh SK, Moorthy KK. Optical, radiative, and source characteristics of aerosols at Minicoy, a remote island in the southern Arabian Sea. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jd011810] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Komppula M, Lihavainen H, Hyvärinen AP, Kerminen VM, Panwar TS, Sharma VP, Viisanen Y. Physical properties of aerosol particles at a Himalayan background site in India. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd011007] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Hyvärinen A, Lihavainen H, Komppula M, Sharma VP, Kerminen V, Panwar TS, Viisanen Y. Continuous measurements of optical properties of atmospheric aerosols in Mukteshwar, northern India. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2008jd011489] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Randles CA, Ramaswamy V. Absorbing aerosols over Asia: A Geophysical Fluid Dynamics Laboratory general circulation model sensitivity study of model response to aerosol optical depth and aerosol absorption. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2008jd010140] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Dey S, Tripathi SN. Aerosol direct radiative effects over Kanpur in the Indo-Gangetic basin, northern India: Long-term (2001–2005) observations and implications to regional climate. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009029] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nair VS, Moorthy KK, Alappattu DP, Kunhikrishnan PK, George S, Nair PR, Babu SS, Abish B, Satheesh SK, Tripathi SN, Niranjan K, Madhavan BL, Srikant V, Dutt CBS, Badarinath KVS, Reddy RR. Wintertime aerosol characteristics over the Indo‐Gangetic Plain (IGP): Impacts of local boundary layer processes and long‐range transport. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd008099] [Citation(s) in RCA: 227] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | | | | | | | | | | | | | - B. Abish
- Space Physics Laboratory VSSC Trivandrum India
| | - S. K. Satheesh
- Centre for Atmospheric and Oceanic Sciences IISc Bangalore India
| | | | - K. Niranjan
- Department of Physics Andhra University Visakhapatnam India
| | - B. L. Madhavan
- Department of Physics Andhra University Visakhapatnam India
| | - V. Srikant
- Department of Physics Andhra University Visakhapatnam India
| | - C. B. S. Dutt
- Indian Space Research Organisation Head Quarters Antariksh Bhavan Bangalore India
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Dey S, Tripathi SN. Estimation of aerosol optical properties and radiative effects in the Ganga basin, northern India, during the wintertime. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd007267] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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