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Shichang Kang - One of the best experts on this subject based on the ideXlab platform.
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Impacts of Indian summer Monsoon and stratospheric intrusion on air pollutants in the inland Tibetan Plateau
'Elsevier BV', 2021Co-Authors: Xiufeng Yin, Shichang Kang, Guoshuai Zhang, Xin Wan, Dipesh Rupakheti, Maheswar Rupakheti, Benjamin De Foy, Zhiyuan Cong, Qianggong ZhangAbstract:Air pollutants can be transported to the pristine regions such as the Tibetan Plateau, by Monsoon and stratospheric intrusion. The Tibetan Plateau region has limited local anthropogenic emissions, while this region is influenced strongly by transport of heavy emissions mainly from South Asia. We conducted a comprehensive study on various air pollutants (PM2.5, total gaseous mercury, and surface ozone) at Nam Co Station in the inland Tibetan Plateau. Monthly mean PM2.5 concentration at Nam Co peaked in April before Monsoon Season, and decreased during the whole Monsoon Season (June–September). Monthly mean total gaseous mercury concentrations at Nam Co peaked in July and were in high levels during Monsoon Season. The Indian summer Monsoon acted as a facilitator for transporting gaseous pollutants (total gaseous mercury) but a suppressor for particulate pollutants (PM2.5) during the Monsoon Season. Different from both PM2.5 and total gaseous mercury variabilities, surface ozone concentrations at Nam Co are primarily attributed to stratospheric intrusion of ozone and peaked in May. The effects of the Indian summer Monsoon and stratospheric intrusion on air pollutants in the inland Tibetan Plateau are complex and require further studies
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severe air pollution and characteristics of light absorbing particles in a typical rural area of the indo gangetic plain
Environmental Science and Pollution Research, 2020Co-Authors: Pengfei Chen, Shichang Kang, Qianggong Zhang, Lekhendra Tripathee, Dipesh Rupakheti, Maheswar Rupakheti, Arnico K Panday, Chaoliu Li, Tao PuAbstract:Total suspended particles (TSP) were collected in Lumbini from April 2013 to March 2016 to better understand the characteristics of carbonaceous aerosol (CA) concentrations, compositions and sources and their light absorption properties in rural region of severe polluted Indo-Gangetic Plain (IGP). Extremely high TSP (203.9 ± 109.6 μg m-3), organic carbon (OC 32.1 ± 21.7 μg m-3), elemental carbon (EC 6.44 ± 3.17 μg m-3) concentrations were observed in Lumbini particularly during winter and post-Monsoon Seasons, reflecting the combined influences of emission sources and weather conditions. SO42- (7.34 ± 4.39 μg m-3) and Ca2+ (5.46 ± 5.20 μg m-3) were the most dominant anion and cation in TSP. These components were comparable to those observed in urban areas in South and East Asia but significantly higher than those in remote regions over the Himalayas and Tibetan Plateau, suggesting severe air pollution in the study region. Various combustion activities including industry, vehicle emission, and biomass burning are the main reasons for high pollutant concentrations. The variation of OC/EC ratio further suggested that biomass such as agro-residue burning contributed a lot for CA, particularly during the non-Monsoon Season. The average mass absorption cross-section of EC (MACEC) and water-soluble organic carbon (MACWSOC) were 7.58 ± 3.39 and 1.52 ± 0.41 m2 g-1, respectively, indicating that CA in Lumbini was mainly affected by local emissions. Increased biomass burning decreased MACEC; whereas, it could result in high MACWSOC during the non-Monsoon Season. Furthermore, dust is one important factor causing higher MACWSOC during the pre-Monsoon Season.
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concentration temporal variation and sources of black carbon in the mt everest region retrieved by real time observation and simulation
Atmospheric Chemistry and Physics, 2018Co-Authors: Xintong Chen, Shichang Kang, Zhiyuan Cong, Junhua YangAbstract:Abstract. Based on the high-resolution measurement of black carbon (BC) at the Qomolangma (Mt. Everest) Station (QOMS, 28.36 ∘ N, 86.95 ∘ E, 4276 m a.s.l.) from 15 May 2015 to 31 May 2017, we investigated the Seasonal and diurnal variations in BC and its potential source regions. Both monthly and daily mean BC concentrations reached the highest values in the pre-Monsoon Season and the lowest values in the Monsoon Season. The highest monthly and daily mean BC concentrations were at least 1 order of magnitude higher than the lowest concentrations. For the diurnal variation, the BC concentrations remained significantly high from late at night to morning in the pre-Monsoon Season. Meanwhile, the westerly winds prevailed during this period, implying the potential for pollutants to be transported across the Himalayas from long-distance sources to QOMS along the valley. In the Monsoon Season, the BC concentrations remained low but peaked in the morning and at noon, which might be caused by local emissions from cooking. By analyzing the simulation results from the backward trajectories of air masses and the fire spot distribution from the MODIS data, we found that the Seasonal cycle of BC was significantly influenced by the atmospheric circulation and combustion intensity in the Mt. Everest region. The transport mechanisms of BC were further revealed using a WRF-Chem simulation during severe pollution episodes. For the pollution event in the Monsoon Season, BC aerosols in southern Asia were uplifted and transported to the Mt. Everest region by the southerly winds in the upper atmosphere. However, for the events in the pre-Monsoon Season, BC from northern India was transported and concentrated on the southern slope of the Himalayas by the northwesterly winds in the lower atmosphere and then transported across the Himalayas by the mountain-valley wind. A relatively smaller amount of BC from northwestern India and central Asia was transported to the Mt. Everest region by the westerly winds in the upper atmosphere.
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Seasonal variation and light absorption property of carbonaceous aerosol in a typical glacier region of the southeastern tibetan plateau
Atmospheric Chemistry and Physics, 2018Co-Authors: Shichang Kang, Hewen Niu, Hailong Wang, Rudong Zhang, Yun Qian, Rukumesh Paudyal, Shijin WangAbstract:Abstract. Deposition and accumulation of light-absorbing carbonaceous aerosol on glacier surfaces can alter the energy balance of glaciers. In this study, 2 years (December 2014 to December 2016) of continuous observations of carbonaceous aerosols in the glacierized region of the Mt. Yulong and Ganhaizi (GHZ) basin are analyzed. The average elemental carbon (EC) and organic carbon (OC) concentrations were 1.51±0.93 and 2.57±1.32 µg m−3 , respectively. Although the annual mean OC ∕ EC ratio was 2.45±1.96 , monthly mean EC concentrations during the post-Monsoon Season were even higher than OC in the high altitudes (approximately 5000 m a . s . l . ) of Mt. Yulong. Strong photochemical reactions and local tourism activities were likely the main factors inducing high OC ∕ EC ratios in the Mt. Yulong region during the Monsoon Season. The mean mass absorption efficiency (MAE) of EC, measured for the first time in Mt. Yulong, at 632 nm with a thermal-optical carbon analyzer using the filter-based method, was 6.82±0.73 m2 g−1 , comparable with the results from other studies. Strong Seasonal and spatial variations of EC MAE were largely related to the OC abundance. Source attribution analysis using a global aerosol–climate model, equipped with a black carbon (BC) source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 %) to annual mean near-surface BC in the Mt. Yulong area. There is also a strong Seasonal variation in the regional source apportionment. South Asia has the largest contribution to near-surface BC during the pre-Monsoon Season, while East Asia dominates the Monsoon Season and post-Monsoon Season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.
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spatio temporal variability and light absorption property of carbonaceous aerosol in a typical glacierization region of the tibetan plateau
Atmospheric Chemistry and Physics, 2017Co-Authors: Hewen Niu, Shichang Kang, Hailong Wang, Rudong Zhang, Yun Qian, Rukumesh Paudyal, Shijin Wang, Xiaofei ShiAbstract:The high altitude glacierized regions of the Tibetan Plateau (TP) are influenced by carbonaceous aerosols from local sources and long range transport from the adjoining areas. Deposition and accumulation of light-absorbing carbonaceous matters on glacier surfaces can alter the energy balance of glaciers. In this study, two years (December 2014 to December 2016) of continuous observations of carbonaceous aerosols performed in glacierized region of Mt. Yulong (4510 m a.s.l.) and Ganhaizi (GHZ) basin (3054 m a.s.l.) are analyzed. The mass absorption efficiency (MAE) of black carbon (BC) was determined for the first time in Mt. Yulong using a thermal-optical carbon analyzer. The average BC and organic carbon (OC) concentrations were 1.51 ± 0.93 and 2.57 ± 1.32 μg m −3 , respectively. The average SOC (secondary OC) concentration, quantified using BC-tracer method, was 1.67 ± 1.15 μg m −3 . Monthly mean BC concentrations from Monsoon to post-Monsoon Season were higher than OC in the high altitudes (approximately 5000 m a.s.l.) of Mt. Yulong. The concentrations of carbonaceous matter have distinct spatial and inter-annual variations in this glacierization area. High carbonaceous matter associated with OC (including both SOC and POC) in GHZ basin was mainly contributed from tour bus emissions. The annual mean OC / BC ratio was 2.45 ± 1.96 in Mt. Yulong. Strong photochemical reactions and local tourism activities in Monsoon Season were the main factors inducing high OC / BC ratios in the Mt. Yulong region. The mean MAE of BC, measured at 632 nm with a thermal-optical protocol under the filter-based method, was 6.82 ± 0.73 m 2 g −1 , comparable with the results from other studies. Strong Seasonal and spatial variations of BC MAE were largely related to the OC and SOC abundance. Source attribution analysis using a global aerosol-climate model, equipped with a BC source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 %) to annual mean near-surface BC at the two sites. There is also a strong Seasonal variation in the regional source apportionment. South Asia has the largest contribution during the pre-Monsoon Season, while East Asia dominates the Monsoon Season and post-Monsoon Season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.
Ritesh Gautam - One of the best experts on this subject based on the ideXlab platform.
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characterization of aerosols over the indochina peninsula from satellite surface observations during biomass burning pre Monsoon Season
Atmospheric Environment, 2013Co-Authors: Ritesh Gautam, Christina N Hsu, T F Eck, B N Holben, Serm Janjai, Treenuch Jantarach, Sichee Tsay, William K M LauAbstract:This paper presents characterization of aerosols over the Indochina peninsular regions of Southeast Asia during pre-Monsoon Season from satellite and ground-based radiometric observations. Our analysis focuses on the Seasonal peak period in aerosol loading and biomass burning, prior to the onset of the Asian summer Monsoon, as observed in the inter-annual variations of Aerosol Optical Depth (AOD) and fire count data from MODIS. Multi-year (2007-2011) analysis of spaceborne lidar measurements, from CALIOP, indicates presence of aerosols mostly within boundary layer, however extending to elevated altitudes to approx. 4 km over northern regions of Indochina, encompassing Myanmar, northern Thailand and southern China. In addition, a strong gradient in aerosol loading and vertical distribution is observed from the relatively clean equatorial conditions to heavy smoke-laden northern regions (greater aerosol extinction and smaller depolarization ratio). Based on column-integrated ground-based measurements from four AERONET locations distributed over Thailand, the regional aerosol loading is found to be significantly absorbing with spectral single scattering albedo (SSA) below 0.91+/-0.02 in the 440-1020 nm range, with lowest Seasonal mean SSA (most absorbing aerosol) over the northern location of Chiang Mai (SSA approx. 0.85) during pre-Monsoon Season. The smoke-laden aerosol loading is found to exhibit a significant diurnal pattern with higher AOD departures during early morning observations relative to late afternoon conditions (peak difference of more than 15% amplitude). Finally, satellite-based aerosol radiative impact is assessed using CERES shortwave Top-of-Atmosphere flux, in conjunction with MODIS AOD. Overall, a consistency in the aerosol-induced solar absorption characteristic is found among selected regions from ground-based sunphotometer-derived spectral SSA retrievals and satellite-based radiative forcing analysis.
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accumulation of aerosols over the indo gangetic plains and southern slopes of the himalayas distribution properties and radiative effects during the 2009 pre Monsoon Season
Atmospheric Chemistry and Physics, 2011Co-Authors: Ritesh Gautam, B N Holben, Sichee Tsay, Shaun W Bell, A Smirnov, Can Li, Richard A HansellAbstract:Abstract. We examine the distribution of aerosols and associated optical/radiative properties in the Gangetic-Himalayan region from simultaneous radiometric measurements over the Indo-Gangetic Plains (IGP) and the foothill/southern slopes of the Himalayas during the 2009 pre-Monsoon Season. Enhanced dust transport extending from the Southwest Asian arid regions into the IGP, results in Seasonal mean (April–June) aerosol optical depths of over 0.6 – highest over Southern Asia. The influence of dust loading is greater over the Western IGP as suggested by pronounced coarse mode peak in aerosol size distribution and spectral single scattering albedo (SSA). Transported dust in the IGP, driven by prevailing westerly airmass, is found to be more absorbing (SSA 550 nm −2 at surface (12–15% of the surface solar insolation). Furthermore, based on limited observations of aerosol optical properties during the pre-Monsoon period and comparison of our radiative forcing estimates with published literature, there exists a general spatial heterogeneity in the regional aerosol forcing, associated with the absorbing aerosol distribution over northern India, with both diurnal mean surface forcing and forcing efficiency over the IGP exceeding that over Northwestern India. Finally, the role of the Seasonal progressive buildup of aerosol loading and water vapor is investigated in the observed net aerosol radiative effect over Northwestern India. The radiative impact of water vapor is found to amplify the net regional aerosol radiative forcing suggesting that the two exert forcing in tandem leading to enhanced surface cooling. It is suggested that water vapor contribution should be taken into account while assessing aerosol forcing impact for this region and other Seasonally similar environments.
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two contrasting dust dominant periods over india observed from modis and calipso data
Geophysical Research Letters, 2009Co-Authors: Ritesh Gautam, Zhaoyan Liu, Ramesh P Singh, Christina N HsuAbstract:[1] Each year, prior to the onset of the Indian Summer Monsoon, the Gangetic Plains (GP), bounded by the high-altitude Himalayan mountains, are strongly influenced by the transport of dust outbreaks originating in the northwestern desert in India (known as the Thar Desert). Dust particles constitute the bulk of the regional aerosol loading which peaks annually during the pre-Monsoon Season. This paper integrates observations from space-borne sensors, namely MODIS and CALIPSO, together with ground sunphotometer measurements, to infer dust loading in the pre-Monsoon aerosol build-up over source and sink regions in northern India. Detailed aerosol characterization from the synergetic observational assessment suggests that the two pre-Monsoon Seasons of 2007 and 2008 were strikingly contrasting in terms of the dust loading over both the Thar Desert and the GP. Further analysis of aerosol loading and optical properties, from the entire record of MODIS and sunphotometer observations, reveals that the 2007 pre-Monsoon Season was an unusually weak dust-laden period. Our findings suggest the plausible role of the immediately preceding excess winter Monsoon rainfall in the suppressed dust activity during the 2007 pre-Monsoon Season.
Qianggong Zhang - One of the best experts on this subject based on the ideXlab platform.
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Impacts of Indian summer Monsoon and stratospheric intrusion on air pollutants in the inland Tibetan Plateau
'Elsevier BV', 2021Co-Authors: Xiufeng Yin, Shichang Kang, Guoshuai Zhang, Xin Wan, Dipesh Rupakheti, Maheswar Rupakheti, Benjamin De Foy, Zhiyuan Cong, Qianggong ZhangAbstract:Air pollutants can be transported to the pristine regions such as the Tibetan Plateau, by Monsoon and stratospheric intrusion. The Tibetan Plateau region has limited local anthropogenic emissions, while this region is influenced strongly by transport of heavy emissions mainly from South Asia. We conducted a comprehensive study on various air pollutants (PM2.5, total gaseous mercury, and surface ozone) at Nam Co Station in the inland Tibetan Plateau. Monthly mean PM2.5 concentration at Nam Co peaked in April before Monsoon Season, and decreased during the whole Monsoon Season (June–September). Monthly mean total gaseous mercury concentrations at Nam Co peaked in July and were in high levels during Monsoon Season. The Indian summer Monsoon acted as a facilitator for transporting gaseous pollutants (total gaseous mercury) but a suppressor for particulate pollutants (PM2.5) during the Monsoon Season. Different from both PM2.5 and total gaseous mercury variabilities, surface ozone concentrations at Nam Co are primarily attributed to stratospheric intrusion of ozone and peaked in May. The effects of the Indian summer Monsoon and stratospheric intrusion on air pollutants in the inland Tibetan Plateau are complex and require further studies
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severe air pollution and characteristics of light absorbing particles in a typical rural area of the indo gangetic plain
Environmental Science and Pollution Research, 2020Co-Authors: Pengfei Chen, Shichang Kang, Qianggong Zhang, Lekhendra Tripathee, Dipesh Rupakheti, Maheswar Rupakheti, Arnico K Panday, Chaoliu Li, Tao PuAbstract:Total suspended particles (TSP) were collected in Lumbini from April 2013 to March 2016 to better understand the characteristics of carbonaceous aerosol (CA) concentrations, compositions and sources and their light absorption properties in rural region of severe polluted Indo-Gangetic Plain (IGP). Extremely high TSP (203.9 ± 109.6 μg m-3), organic carbon (OC 32.1 ± 21.7 μg m-3), elemental carbon (EC 6.44 ± 3.17 μg m-3) concentrations were observed in Lumbini particularly during winter and post-Monsoon Seasons, reflecting the combined influences of emission sources and weather conditions. SO42- (7.34 ± 4.39 μg m-3) and Ca2+ (5.46 ± 5.20 μg m-3) were the most dominant anion and cation in TSP. These components were comparable to those observed in urban areas in South and East Asia but significantly higher than those in remote regions over the Himalayas and Tibetan Plateau, suggesting severe air pollution in the study region. Various combustion activities including industry, vehicle emission, and biomass burning are the main reasons for high pollutant concentrations. The variation of OC/EC ratio further suggested that biomass such as agro-residue burning contributed a lot for CA, particularly during the non-Monsoon Season. The average mass absorption cross-section of EC (MACEC) and water-soluble organic carbon (MACWSOC) were 7.58 ± 3.39 and 1.52 ± 0.41 m2 g-1, respectively, indicating that CA in Lumbini was mainly affected by local emissions. Increased biomass burning decreased MACEC; whereas, it could result in high MACWSOC during the non-Monsoon Season. Furthermore, dust is one important factor causing higher MACWSOC during the pre-Monsoon Season.
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organic molecular tracers in the atmospheric aerosols from lumbini nepal in the northern indo gangetic plain influence of biomass burning
Atmospheric Chemistry and Physics, 2017Co-Authors: Xin Wan, Shichang Kang, Qianggong Zhang, Junming Guo, Lekhendra Tripathee, Dipesh Rupakheti, Pengfei Chen, Maheswar Rupakheti, Arnico K PandayAbstract:Abstract. To better understand the characteristics of biomass burning in the northern Indo-Gangetic Plain (IGP), total suspended particles were collected in a rural site, Lumbini, Nepal, during April 2013 to March 2014 and analyzed for the biomass burning tracers (i.e., levoglucosan, mannosan, vanillic acid). The annual average concentration of levoglucosan was 734 ± 1043 ng m−3 with the maximum Seasonal mean concentration during post-Monsoon Season (2206 ± 1753 ng m−3), followed by winter (1161 ± 1347 ng m−3), pre-Monsoon (771 ± 524 ng m−3) and minimum concentration during Monsoon Season (212 ± 279 ng m−3). The other biomass burning tracers (mannosan, galactosan, p-hydroxybenzoic acid, vanillic acid, syringic acid and dehydroabietic acid) also showed the similar Seasonal variations. There were good correlations among levoglucosan, organic carbon (OC) and elemental carbon (EC), indicating significant impact of biomass burning activities on carbonaceous aerosol loading throughout the year in Lumbini area. According to the characteristic ratios, levoglucosan ∕ mannosan (lev ∕ man) and syringic acid ∕ vanillic acid (syr ∕ van), we deduced that the high abundances of biomass burning products during non-Monsoon Seasons were mainly caused by the burning of crop residues and hardwood while the softwood had less contribution. Based on the diagnostic tracer ratio (i.e., lev ∕ OC), the OC derived from biomass burning constituted large fraction of total OC, especially during post-Monsoon Season. By analyzing the MODIS fire spot product and 5-day air-mass back trajectories, we further demonstrated that organic aerosol composition was not only related to the local agricultural activities and residential biomass usage but also impacted by the regional emissions. During the post-Monsoon Season, the emissions from rice residue burning in western India and eastern Pakistan could impact particulate air pollution in Lumbini and surrounding regions in southern Nepal. Therefore, our finding is meaningful and has a great importance for adopting the appropriate mitigation measures, not only at the local level but also by involving different regions and nations, to reduce the biomass burning emissions in the broader IGP region nations.
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atmospheric particulate mercury in lhasa city tibetan plateau
Atmospheric Environment, 2016Co-Authors: Jie Huang, Shichang Kang, Qianggong Zhang, Junming Guo, Guoshuai Zhang, Zhiyuan Cong, Mika Sillanpaa, Shiwei SunAbstract:Abstract In an effort to understand the biogeochemical cycling and Seasonal characteristics of atmospheric Hg, a total of 80 daily sampled total suspended particulates were collected at Lhasa, the largest city of Tibet, from April 2013 to August 2014 for particulate-bound Hg (Hg P ) analysis. Daily concentrations of atmospheric Hg P ranged from 61.2 to 831 pg m −3 with an average of 224 pg m −3 , which were unexpectedly comparable to those measured in most of the Chinese metropolises. Both the daily/monthly average Hg P concentrations were slightly but not significantly higher during the non-Monsoon Season than during the Monsoon Season. Together with the fact that there was lack of significant relationship between Hg P concentration and most meteorological parameters, no significant and distinct pattern for the Seasonal characteristics of atmospheric Hg P could be mainly attributed to the almost equal emission strength of two principal anthropogenic Hg sources (i.e., industrial emission sources during the non-Monsoon Season, and vehicular traffic and religious sources during the Monsoon Season). Moreover, the Hg P dry deposition rate was estimated to be 35.3 μg m −2 yr −1 by using a theoretical model, which was significantly higher than those Hg wet fluxes. The elevated deposition rate implied that dry deposition may play an important role in the biogeochemical Hg cycling over the Tibetan Plateau.
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characterizations of wet mercury deposition on a remote high elevation site in the southeastern tibetan plateau
Environmental Pollution, 2015Co-Authors: Jie Huang, Shichang Kang, Qianggong Zhang, Junming Guo, Mika Sillanpaa, Shiwei Sun, Yongjie Wang, Xuejun Sun, Lekhendra TripatheeAbstract:Accurate measurements of wet mercury (Hg) deposition are critically important for the assessment of ecological responses to pollutant loading. The Hg in wet deposition was measured over a 3-year period in the southeastern Tibetan Plateau. The volume-weighted mean (VWM) total Hg (HgT) concentration was somewhat lower than those reported in other regions of the Tibetan Plateau, but the VWM methyl-Hg concentration and deposition flux were among the highest globally reported values. The VWM HgT concentration was higher in non-Monsoon Season than in Monsoon Season, and wet HgT deposition was dominated by the precipitation amount rather than the scavenging of atmospheric Hg by precipitation. The dominant Hg species in precipitation was mainly in the form of dissolved Hg, which indicates the pivotal role of reactive gaseous Hg within-cloud scavenging to wet Hg deposition. Moreover, an increasing trend in precipitation Hg concentrations was synchronous with the recent economic development in South Asia.
Hewen Niu - One of the best experts on this subject based on the ideXlab platform.
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Seasonal variation and light absorption property of carbonaceous aerosol in a typical glacier region of the southeastern tibetan plateau
Atmospheric Chemistry and Physics, 2018Co-Authors: Shichang Kang, Hewen Niu, Hailong Wang, Rudong Zhang, Yun Qian, Rukumesh Paudyal, Shijin WangAbstract:Abstract. Deposition and accumulation of light-absorbing carbonaceous aerosol on glacier surfaces can alter the energy balance of glaciers. In this study, 2 years (December 2014 to December 2016) of continuous observations of carbonaceous aerosols in the glacierized region of the Mt. Yulong and Ganhaizi (GHZ) basin are analyzed. The average elemental carbon (EC) and organic carbon (OC) concentrations were 1.51±0.93 and 2.57±1.32 µg m−3 , respectively. Although the annual mean OC ∕ EC ratio was 2.45±1.96 , monthly mean EC concentrations during the post-Monsoon Season were even higher than OC in the high altitudes (approximately 5000 m a . s . l . ) of Mt. Yulong. Strong photochemical reactions and local tourism activities were likely the main factors inducing high OC ∕ EC ratios in the Mt. Yulong region during the Monsoon Season. The mean mass absorption efficiency (MAE) of EC, measured for the first time in Mt. Yulong, at 632 nm with a thermal-optical carbon analyzer using the filter-based method, was 6.82±0.73 m2 g−1 , comparable with the results from other studies. Strong Seasonal and spatial variations of EC MAE were largely related to the OC abundance. Source attribution analysis using a global aerosol–climate model, equipped with a black carbon (BC) source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 %) to annual mean near-surface BC in the Mt. Yulong area. There is also a strong Seasonal variation in the regional source apportionment. South Asia has the largest contribution to near-surface BC during the pre-Monsoon Season, while East Asia dominates the Monsoon Season and post-Monsoon Season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.
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spatio temporal variability and light absorption property of carbonaceous aerosol in a typical glacierization region of the tibetan plateau
Atmospheric Chemistry and Physics, 2017Co-Authors: Hewen Niu, Shichang Kang, Hailong Wang, Rudong Zhang, Yun Qian, Rukumesh Paudyal, Shijin Wang, Xiaofei ShiAbstract:The high altitude glacierized regions of the Tibetan Plateau (TP) are influenced by carbonaceous aerosols from local sources and long range transport from the adjoining areas. Deposition and accumulation of light-absorbing carbonaceous matters on glacier surfaces can alter the energy balance of glaciers. In this study, two years (December 2014 to December 2016) of continuous observations of carbonaceous aerosols performed in glacierized region of Mt. Yulong (4510 m a.s.l.) and Ganhaizi (GHZ) basin (3054 m a.s.l.) are analyzed. The mass absorption efficiency (MAE) of black carbon (BC) was determined for the first time in Mt. Yulong using a thermal-optical carbon analyzer. The average BC and organic carbon (OC) concentrations were 1.51 ± 0.93 and 2.57 ± 1.32 μg m −3 , respectively. The average SOC (secondary OC) concentration, quantified using BC-tracer method, was 1.67 ± 1.15 μg m −3 . Monthly mean BC concentrations from Monsoon to post-Monsoon Season were higher than OC in the high altitudes (approximately 5000 m a.s.l.) of Mt. Yulong. The concentrations of carbonaceous matter have distinct spatial and inter-annual variations in this glacierization area. High carbonaceous matter associated with OC (including both SOC and POC) in GHZ basin was mainly contributed from tour bus emissions. The annual mean OC / BC ratio was 2.45 ± 1.96 in Mt. Yulong. Strong photochemical reactions and local tourism activities in Monsoon Season were the main factors inducing high OC / BC ratios in the Mt. Yulong region. The mean MAE of BC, measured at 632 nm with a thermal-optical protocol under the filter-based method, was 6.82 ± 0.73 m 2 g −1 , comparable with the results from other studies. Strong Seasonal and spatial variations of BC MAE were largely related to the OC and SOC abundance. Source attribution analysis using a global aerosol-climate model, equipped with a BC source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 %) to annual mean near-surface BC at the two sites. There is also a strong Seasonal variation in the regional source apportionment. South Asia has the largest contribution during the pre-Monsoon Season, while East Asia dominates the Monsoon Season and post-Monsoon Season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.
Rudong Zhang - One of the best experts on this subject based on the ideXlab platform.
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Seasonal variation and light absorption property of carbonaceous aerosol in a typical glacier region of the southeastern tibetan plateau
Atmospheric Chemistry and Physics, 2018Co-Authors: Shichang Kang, Hewen Niu, Hailong Wang, Rudong Zhang, Yun Qian, Rukumesh Paudyal, Shijin WangAbstract:Abstract. Deposition and accumulation of light-absorbing carbonaceous aerosol on glacier surfaces can alter the energy balance of glaciers. In this study, 2 years (December 2014 to December 2016) of continuous observations of carbonaceous aerosols in the glacierized region of the Mt. Yulong and Ganhaizi (GHZ) basin are analyzed. The average elemental carbon (EC) and organic carbon (OC) concentrations were 1.51±0.93 and 2.57±1.32 µg m−3 , respectively. Although the annual mean OC ∕ EC ratio was 2.45±1.96 , monthly mean EC concentrations during the post-Monsoon Season were even higher than OC in the high altitudes (approximately 5000 m a . s . l . ) of Mt. Yulong. Strong photochemical reactions and local tourism activities were likely the main factors inducing high OC ∕ EC ratios in the Mt. Yulong region during the Monsoon Season. The mean mass absorption efficiency (MAE) of EC, measured for the first time in Mt. Yulong, at 632 nm with a thermal-optical carbon analyzer using the filter-based method, was 6.82±0.73 m2 g−1 , comparable with the results from other studies. Strong Seasonal and spatial variations of EC MAE were largely related to the OC abundance. Source attribution analysis using a global aerosol–climate model, equipped with a black carbon (BC) source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 %) to annual mean near-surface BC in the Mt. Yulong area. There is also a strong Seasonal variation in the regional source apportionment. South Asia has the largest contribution to near-surface BC during the pre-Monsoon Season, while East Asia dominates the Monsoon Season and post-Monsoon Season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.
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spatio temporal variability and light absorption property of carbonaceous aerosol in a typical glacierization region of the tibetan plateau
Atmospheric Chemistry and Physics, 2017Co-Authors: Hewen Niu, Shichang Kang, Hailong Wang, Rudong Zhang, Yun Qian, Rukumesh Paudyal, Shijin Wang, Xiaofei ShiAbstract:The high altitude glacierized regions of the Tibetan Plateau (TP) are influenced by carbonaceous aerosols from local sources and long range transport from the adjoining areas. Deposition and accumulation of light-absorbing carbonaceous matters on glacier surfaces can alter the energy balance of glaciers. In this study, two years (December 2014 to December 2016) of continuous observations of carbonaceous aerosols performed in glacierized region of Mt. Yulong (4510 m a.s.l.) and Ganhaizi (GHZ) basin (3054 m a.s.l.) are analyzed. The mass absorption efficiency (MAE) of black carbon (BC) was determined for the first time in Mt. Yulong using a thermal-optical carbon analyzer. The average BC and organic carbon (OC) concentrations were 1.51 ± 0.93 and 2.57 ± 1.32 μg m −3 , respectively. The average SOC (secondary OC) concentration, quantified using BC-tracer method, was 1.67 ± 1.15 μg m −3 . Monthly mean BC concentrations from Monsoon to post-Monsoon Season were higher than OC in the high altitudes (approximately 5000 m a.s.l.) of Mt. Yulong. The concentrations of carbonaceous matter have distinct spatial and inter-annual variations in this glacierization area. High carbonaceous matter associated with OC (including both SOC and POC) in GHZ basin was mainly contributed from tour bus emissions. The annual mean OC / BC ratio was 2.45 ± 1.96 in Mt. Yulong. Strong photochemical reactions and local tourism activities in Monsoon Season were the main factors inducing high OC / BC ratios in the Mt. Yulong region. The mean MAE of BC, measured at 632 nm with a thermal-optical protocol under the filter-based method, was 6.82 ± 0.73 m 2 g −1 , comparable with the results from other studies. Strong Seasonal and spatial variations of BC MAE were largely related to the OC and SOC abundance. Source attribution analysis using a global aerosol-climate model, equipped with a BC source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 %) to annual mean near-surface BC at the two sites. There is also a strong Seasonal variation in the regional source apportionment. South Asia has the largest contribution during the pre-Monsoon Season, while East Asia dominates the Monsoon Season and post-Monsoon Season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.