Influence of biomass burning from Southeast Asia at a high-altitude mountain receptor site in China

Abstract. Highly time-resolved in-situ measurements of airborne particles were made at Mt. Yulong (3410 m above sea level) on the southeastern edge of the Tibetan Plateau in China from 20 March to 14 April in 2015. Detailed chemical composition was measured by a high-resolution time-of-flight aerosol mass spectrometer together with other online instruments. Average mass concentration of the submicron particles (PM1) was 5.7 ± 5.4 μg m−3 during the field campaign, ranging from 0.1 μg m−3 up to 33.3 μg m−3. Organic aerosol (OA) was the dominant component in PM1, with a fraction of 68 %. Three OA factors, i.e., biomass-burning organic aerosol (BBOA), biomass-burning-influenced oxygenated organic aerosol (OOA-BB) and oxygenated organic aerosol (OOA), were resolved using positive matrix factorization analysis. The two oxygenated OA factors accounted for 87 % of the total OA mass. Three biomass burning events were identified by examining the enhancement of black carbon concentrations and the f60 (the ratio of the signal at m/z 60 from the mass spectrum to the total signal of OA). Back trajectories of air masses and satellite fire map data were integrated to identify the biomass burning locations and pollutants transport. The western air mass from Southeast Asia with active biomass burning activities transported large amount of air pollutants, resulting in elevated organic concentrations up to 4-fold higher than that of the background condition. This study at Mt. Yulong characterizes the tropospheric background aerosols of the Tibetan Plateau during pre-monsoon season, and provides clear evidence that the southeastern edge of the Tibetan Plateau is affected by transport of anthropogenic aerosols from Southeast Asia.

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Influence of biomass burning from South Asia at a high-altitude mountain receptor site in China

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-6853-2017 ◽

2017 ◽

Vol 17 (11) ◽

pp. 6853-6864 ◽

Cited By ~ 17

Author(s):

Jing Zheng ◽

Min Hu ◽

Zhuofei Du ◽

Dongjie Shang ◽

Zhaoheng Gong ◽

...

Keyword(s):

Tibetan Plateau ◽

South Asia ◽

Biomass Burning ◽

Monsoon Season ◽

Organic Aerosol ◽

Submicron Particles ◽

The Tibetan Plateau ◽

Anthropogenic Aerosols ◽

Air Masses ◽

Average Mass

Abstract. Highly time-resolved in situ measurements of airborne particles were conducted at Mt. Yulong (3410 m above sea level) on the southeastern edge of the Tibetan Plateau in China from 22 March to 14 April 2015. The detailed chemical composition was measured by a high-resolution time-of-flight aerosol mass spectrometer together with other online instruments. The average mass concentration of the submicron particles (PM1) was 5.7 ± 5.4 µg m−3 during the field campaign, ranging from 0.1 up to 33.3 µg m−3. Organic aerosol (OA) was the dominant component in PM1, with a fraction of 68 %. Three OA factors, i.e., biomass burning organic aerosol (BBOA), biomass-burning-influenced oxygenated organic aerosol (OOA-BB) and oxygenated organic aerosol (OOA), were resolved using positive matrix factorization analysis. The two oxygenated OA factors accounted for 87 % of the total OA mass. Three biomass burning events were identified by examining the enhancement of black carbon concentrations and the f60 (the ratio of the signal at m∕z 60 from the mass spectrum to the total signal of OA). Back trajectories of air masses and satellite fire map data were integrated to identify the biomass burning locations and pollutant transport. The western air masses from South Asia with active biomass burning activities transported large amounts of air pollutants, resulting in elevated organic concentrations up to 4-fold higher than those of the background conditions. This study at Mt. Yulong characterizes the tropospheric background aerosols of the Tibetan Plateau during pre-monsoon season and provides clear evidence that the southeastern edge of the Tibetan Plateau was affected by the transport of anthropogenic aerosols from South Asia.

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Strong Light Absorption Induced by Aged Biomass Burning Black Carbon over the Southeastern Tibetan Plateau in Pre-monsoon Season

10.5194/acp-2020-1150 ◽

2020 ◽

Author(s):

Tianyi Tan ◽

Min Hu ◽

Zhuofei Du ◽

Gang Zhao ◽

Dongjie Shang ◽

...

Keyword(s):

Tibetan Plateau ◽

Black Carbon ◽

Biomass Burning ◽

Climate Warming ◽

Light Absorption ◽

Monsoon Season ◽

Absorption Enhancement ◽

The Tibetan Plateau ◽

Mixing State ◽

Strong Light

Abstract. During the pre-monsoon season, biomass burning (BB) activities are intensive in southern Asia. Facilitated by westerly circulation, those BB plumes can be transported to the Tibetan Plateau (TP). Black carbon (BC), the main aerosol species in BB emissions, is an important climate warming agent, and its absorbing property strongly depends on its size distribution and mixing state. To elucidate the influence of those transported BB plumes on the TP, a field campaign was conducted on the southeast edge of the TP during the pre-monsoon season. It was found that the transported BB plumes substantially increased the number concentration of the atmospheric BC particles by 13 times, and greatly elevated the number fraction of thickly-coated BC from 52 % up to 91 %. Those transported BC particles had slightly larger core size and much thicker coatings than the background BC particles. However, the coating mass was not evenly distributed on BC particles with different sizes. The smaller BC cores were found to have larger shell/core ratios than the larger cores. Besides, the transported BB plumes strongly affected the vertical variation of the BC's abundance and mixing state, resulting in a higher concentration, larger number fraction and higher aging degree of BC particles in the upper atmosphere. Resulted from both increase of BC loading and aging degree, the transported BB plumes eventually enhanced the total light absorption by 15 times, in which 21 % was contributed by the BC aging and 79 % was contributed from the increase of BC mass. Particularly, the light absorption enhancement induced by the aging process during long-range transport has far exceeded the background aerosol light absorption, which implicates a significant influence of BC aging on climate warming over the TP region.

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Measurement report: Strong light absorption induced by aged biomass burning black carbon over the southeastern Tibetan Plateau in pre-monsoon season

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-8499-2021 ◽

2021 ◽

Vol 21 (11) ◽

pp. 8499-8510

Author(s):

Tianyi Tan ◽

Min Hu ◽

Zhuofei Du ◽

Gang Zhao ◽

Dongjie Shang ◽

...

Keyword(s):

Tibetan Plateau ◽

Black Carbon ◽

Biomass Burning ◽

Climate Warming ◽

Light Absorption ◽

Monsoon Season ◽

Absorption Enhancement ◽

The Tibetan Plateau ◽

Mixing State ◽

Strong Light

Abstract. During the pre-monsoon season, biomass burning (BB) activities are intensive in southern Asia. Facilitated by westerly circulation, those BB plumes can be transported to the Tibetan Plateau (TP). Black carbon (BC), the main aerosol species in BB emissions, is an important climate warming agent, and its absorbing property strongly depends on its size distribution and mixing state. To elucidate the influence of those transported BB plumes on the TP, a field campaign was conducted on the southeast edge of the TP during the pre-monsoon season. It was found that the transported BB plumes substantially increased the number concentration of the atmospheric BC particles by a factor of 13 and greatly elevated the number fraction of thickly coated BC from 52 % up to 91 %. Those transported BC particles had slightly larger core size and much thicker coatings than the background BC particles. However, the coating mass was not evenly distributed on BC particles with different sizes. The smaller BC cores were found to have larger shell / core ratios than the larger cores. Besides, the transported BB plumes strongly affected the vertical variation in the BC's abundance and mixing state, resulting in a higher concentration, larger number fraction, and higher aging degree of BC particles in the upper atmosphere. Resulting from both increase in BC loading and aging degree, the transported BB plumes eventually enhanced the total light absorption by a factor of 15, of which 21 % was contributed by the BC aging, and 79 % was contributed from the increase in BC mass. Particularly, the light absorption enhancement induced by the aging process during long-range transport has far exceeded the background aerosol light absorption, which implicates a significant influence of BC aging on climate warming over the TP region.

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The composition and variability of atmospheric aerosol over Southeast Asia during 2008

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-1083-2012 ◽

2012 ◽

Vol 12 (2) ◽

pp. 1083-1100 ◽

Cited By ~ 11

Author(s):

W. Trivitayanurak ◽

P. I. Palmer ◽

M. P. Barkley ◽

N. H. Robinson ◽

H. Coe ◽

...

Keyword(s):

Southeast Asia ◽

Gas Phase ◽

Biomass Burning ◽

Organic Aerosol ◽

Sea Salt ◽

Dust Aerosol ◽

Small Scale ◽

Formation Mechanisms ◽

Sulphate Aerosol ◽

Phase Oxidation

Abstract. We use a nested version of the GEOS-Chem global 3-D chemistry transport model to better understand the composition and variation of aerosol over Borneo and the broader Southeast Asian region in conjunction with aircraft and satellite observations. Our focus on Southeast Asia reflects the importance of this region as a source of reactive organic gases and aerosols from natural forests, biomass burning, and food and fuel crops. We particularly focus on July 2008 when the UK BAe-146 research aircraft was deployed over northern Malaysian Borneo as part of the ACES/OP3 measurement campaign. During July 2008 we find using the model that Borneo (defined as Borneo Island and the surrounding Indonesian islands) was a net exporter of primary organic aerosol (42 kT) and black carbon aerosol (11 kT). We find only 13% of volatile organic compound oxidation products partition to secondary organic aerosol (SOA), with Borneo being a net exporter of SOA (15 kT). SOA represents approximately 19% of the total organic aerosol over the region. Sulphate is mainly from aqueous-phase oxidation (68%), with smaller contributions from gas-phase oxidation (15%) and advection into the regions (14%). We find that there is a large source of sea salt, as expected, but this largely deposits within the region; we find that dust aerosol plays only a relatively small role in the aerosol burden. In contrast to coincident surface measurements over Northern Borneo that find a pristine environment with evidence for substantial biogenic SOA formation we find that the free troposphere is influenced by biomass burning aerosol transported from the northwest of the Island and further afield. We find several transport events during July 2008 over Borneo associated with elevated aerosol concentrations, none of which coincide with the aircraft flights. We use MODIS aerosol optical depths (AOD) data and the model to put the July campaign into a longer temporal perspective. We find that Borneo is where the model has the least skill at reproducing the data, where the model has a negative bias of 76% and only captures 14% of the observed variability. This model performance reflects the small-scale island-marine environment and the mix of aerosol species, with the model showing more skill at reproducing observed AOD over larger continental regions such as China where AOD is dominated by one aerosol type. The model shows that AOD over Borneo is approximately evenly split between organic and sulphate aerosol with sea salt representing 10–20% during May–September; we find a similar breakdown over continental Southeast Asia but with less sea salt aerosol and more dust aerosol. In contrast, East China AOD is determined mainly by sulphate aerosol and a seasonal source of dust aerosol, as expected. Realistic sensitivity runs, designed to test our underlying assumptions about emissions and chemistry over Borneo, show that model AOD is most sensitive to isoprene emissions and organic gas-phase partitioning but all fail to improve significantly upon the control model calculation. This emphasises the multi-faceted dimension of the problem and the need for concurrent and coordinated development of BVOC emissions, and BVOC chemistry and organic aerosol formation mechanisms.

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Condensing Life Substances within the House: The Rice-Boiling Shuhi of Southwest China

Asiatische Studien – Études Asiatiques ◽

10.1515/asia-2016-0023 ◽

2017 ◽

Vol 71 (1) ◽

Author(s):

Elisabeth Hsu ◽

Franz K. Huber ◽

Caroline S. Weckerle

Keyword(s):

Tibetan Plateau ◽

Southeast Asia ◽

High Altitude ◽

Sea Level ◽

Ethnic Groups ◽

Southwest China ◽

Cultural Practice ◽

The Tibetan Plateau ◽

Regional Culture ◽

Fault Line

AbstractThe Shuhi of Muli County, Sichuan Province, are one of multiple ethnic groups inhabiting the river gorges of the Qinghai-Gansu-Sichuan corridor between the Tibetan plateau and the Chinese lowlands. The Shuhi have grown paddy rice since times immemorial at an unusually high altitude (ca. 2,300 m above sea level). This article aims to explain this conundrum not merely through the ecology (as is common among Tibetan area specialists), but by researching the cultivation and consumption of rice as a historically-evolved cultural practice. According to a recently formulated agro-archaeological hypothesis regarding the macro-region of Eurasia, it is possible to identify two supra-regional culture complexes distinguished by their respective culinary technologies: rice-boiling versus wheat-grinding-and-baking. The hypothesis posits that the fault line between the two supra-regional cultural complexes is precisely along this river gorges corridor. In this article we provide support for this hypothesis arguing that Shuhi ritual and kinship practices have much affinity with those of other rice-boiling peoples in Southeast Asia, whereas certain of their current religious practices are shared with the wheat-grinding Tibetans.

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Contribution of South Asian biomass burning to black carbon over the Tibetan Plateau and its climatic impact

Environmental Pollution ◽

10.1016/j.envpol.2020.116195 ◽

2021 ◽

Vol 270 ◽

pp. 116195

Author(s):

Junhua Yang ◽

Zhenming Ji ◽

Shichang Kang ◽

Lekhendra Tripathee

Keyword(s):

Tibetan Plateau ◽

Black Carbon ◽

South Asian ◽

Biomass Burning ◽

The Tibetan Plateau ◽

Climatic Impact

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Air pollution slows down surface warming over the Tibetan Plateau

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-881-2020 ◽

2020 ◽

Vol 20 (2) ◽

pp. 881-899 ◽

Cited By ~ 1

Author(s):

Aolin Jia ◽

Shunlin Liang ◽

Dongdong Wang ◽

Bo Jiang ◽

Xiaotong Zhang

Keyword(s):

Climate Change ◽

Air Pollution ◽

Tibetan Plateau ◽

Air Temperature ◽

Surface Radiation ◽

Shortwave Radiation ◽

Cmip5 Models ◽

The Tibetan Plateau ◽

Anthropogenic Aerosols ◽

Surface Warming

Abstract. The Tibetan Plateau (TP) plays a vital role in regional and global climate change. The TP has been undergoing significant surface warming starting from 1850, with an air temperature increase of 1.39 K and surface solar dimming resulting from decreased incident solar radiation. The causes and impacts of solar dimming on surface warming are unclear. In this study, long-term (from 1850 to 2015) surface downward radiation datasets over the TP are developed by integrating 18 Coupled Model Intercomparison Project phase 5 (CMIP5) models and satellite products. The validation results from two ground measurement networks show that the generated downward surface radiation datasets have a higher accuracy than the mean of multiple CMIP5 datasets and the fused datasets of reanalysis and satellite products. After analyzing the generated radiation data with four air temperature datasets, we found that downward shortwave radiation (DSR) remained stable before 1950 and then declined rapidly at a rate of −0.53 W m−2 per decade, and that the fastest decrease in DSR occurs in the southeastern TP. Evidence from site measurements, satellite observations, reanalysis, and model simulations suggested that the TP solar dimming was primarily driven by increased anthropogenic aerosols. The TP solar dimming is stronger in summer, at the same time that the increasing magnitude of the surface air temperature is the smallest. The cooling effect of solar dimming offsets surface warming on the TP by 0.80±0.28 K (48.6±17.3 %) in summer since 1850. It helps us understand the role of anthropogenic aerosols in climate warming and highlights the need for additional studies to be conducted to quantify the influence of air pollution on regional climate change over the TP.

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Air pollution slows down surface warming over the Tibetan Plateau

10.5194/acp-2019-553 ◽

2019 ◽

Author(s):

Aolin Jia ◽

Shunlin Liang ◽

Dongdong Wang ◽

Bo Jiang ◽

Xiaotong Zhang

Keyword(s):

Climate Change ◽

Air Pollution ◽

Tibetan Plateau ◽

Air Temperature ◽

Surface Radiation ◽

Shortwave Radiation ◽

Cmip5 Models ◽

The Tibetan Plateau ◽

Anthropogenic Aerosols ◽

Surface Warming

Abstract. The Tibetan Plateau (TP) plays a vital role in regional and global climate change. The TP has been undergoing significant surface warming since 1850, with an air temperature increase of 1.39 K and surface solar dimming resulting from decreased incident solar radiation. The causes and impacts of solar dimming on surface warming are unclear. In this study, long-term (from 1850–2015) surface downward radiation datasets over the TP are developed by integrating 18 Coupled Model Intercomparison Project Phase 5 (CMIP5) models and satellite products. The validation results from two ground measurement networks show that the generated downward surface radiation datasets have higher accuracy than the mean of multiple CMIP5 and the fused datasets of reanalysis and satellite products. After analyzing the generated radiation data with four air temperature datasets, we found that downward shortwave radiation (DSR) remained stable before 1950 and then declined rapidly at a rate of −0.53 W m−2 per decade and that the fastest decrease in DSR is in the southeastern TP. Evidence from site measurements, satellite observations, reanalysis, and model simulations suggested that TP solar dimming was primarily driven by increased anthropogenic aerosols. The TP solar dimming is stronger in summer, at the same time that the increasing magnitude of the surface air temperature is the smallest. The cooling effect of solar dimming offsets surface warming on the TP by 0.80 ± 0.28 K (48.6 ± 17.3 %) in summer. It helps us understand the role of anthropogenic aerosols in climate warming, and highlights the need for additional studies to be conducted to quantify the influence of air pollution on regional climate change over the TP.

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Impact of topography on black carbon transport to the southern Tibetan Plateau during the pre-monsoon season and its climatic implication

Atmospheric Chemistry and Physics ◽

10.5194/acp-20-5923-2020 ◽

2020 ◽

Vol 20 (10) ◽

pp. 5923-5943 ◽

Cited By ~ 2

Author(s):

Meixin Zhang ◽

Chun Zhao ◽

Zhiyuan Cong ◽

Qiuyan Du ◽

Mingyue Xu ◽

...

Keyword(s):

Tibetan Plateau ◽

Black Carbon ◽

Radiative Forcing ◽

Monsoon Season ◽

Radiative Heating ◽

The Tibetan Plateau ◽

Complex Topography ◽

Meridional Transport ◽

Near Surface ◽

Mass Volume

Abstract. Most previous modeling studies about black carbon (BC) transport and its impact over the Tibetan Plateau (TP) conducted simulations with horizontal resolutions coarser than 20 km that may not be able to resolve the complex topography of the Himalayas well. In this study, the two experiments covering all of the Himalayas with the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) at the horizontal resolution of 4 km but with two different topography datasets (4 km complex topography and 20 km smooth topography) are conducted for pre-monsoon season (April 2016) to investigate the impacts of topography on modeling the transport and distribution of BC over the TP. Both experiments show the evident accumulation of aerosols near the southern Himalayas during the pre-monsoon season, consistent with the satellite retrievals. The observed episode of high surface BC concentration at the station near Mt. Everest due to heavy biomass burning near the southern Himalayas is well captured by the simulations. The simulations indicate that the prevailing upflow across the Himalayas driven by the large-scale westerly and small-scale southerly circulations during the daytime is the dominant transport mechanism of southern Asian BC into the TP, and it is much stronger than that during the nighttime. The simulation with the 4 km topography resolves more valleys and mountain ridges and shows that the BC transport across the Himalayas can overcome the majority of mountain ridges, but the valley transport is more efficient. The complex topography results in stronger overall cross-Himalayan transport during the simulation period primarily due to the strengthened efficiency of near-surface meridional transport towards the TP, enhanced wind speed at some valleys and deeper valley channels associated with larger transported BC mass volume. This results in 50 % higher transport flux of BC across the Himalayas and 30 %–50 % stronger BC radiative heating in the atmosphere up to 10 km over the TP from the simulation with the 4 km complex topography than that with the 20 km smoother topography. The different topography also leads to different distributions of snow cover and BC forcing in snow. This study implies that the relatively smooth topography used by the models with resolutions coarser than 20 km may introduce significant negative biases in estimating light-absorbing aerosol radiative forcing over the TP during the pre-monsoon season. Highlights. The black carbon (BC) transport across the Himalayas can overcome the majority of mountain ridges, but the valley transport is much more efficient during the pre-monsoon season. The complex topography results in stronger overall cross-Himalayan transport during the study period primarily due to the strengthened efficiency of near-surface meridional transport towards the TP, enhanced wind speed at some valleys and deeper valley channels associated with larger transported BC mass volume. The complex topography generates 50 % higher transport flux of BC across the Himalayas and 30 %–50 % stronger BC radiative heating in the atmosphere up to 10 km over the Tibetan Plateau (TP) than the smoother topography, which implies that the smooth topography used by the models with relatively coarse resolution may introduce significant negative biases in estimating BC radiative forcing over the TP during the pre-monsoon season. The different topography also leads to different distributions of snow cover and BC forcing in snow over the TP.

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Levoglucosan concentrations in ice-core samples from the Tibetan Plateau determined by reverse-phase high-performance liquid chromatography–mass spectrometry

Journal of Glaciology ◽

10.3189/2013jog12j157 ◽

2013 ◽

Vol 59 (216) ◽

pp. 599-612 ◽

Cited By ~ 20

Author(s):

Ping Yao ◽

Valérie F. Schwab ◽

Vanessa-Nina Roth ◽

Baiqing Xu ◽

Tandong Yao ◽

...

Keyword(s):

Mass Spectrometry ◽

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Tibetan Plateau ◽

Biomass Burning ◽

High Performance ◽

Ice Core ◽

Water Soluble ◽

The Tibetan Plateau ◽

Core Samples

AbstractLevoglucosan is a unique marker for biomass burning that can be transported in the atmosphere and preserved in archives such as ice cores. A new method to determine the concentrations of levoglucosan in Tibetan ice-core samples using high-performance liquid chromatography with electrospray ionization mass spectrometry (HPLC-ESI/MS) was developed. Levoglucosan was separated from coeluting water-soluble organic compounds using a C18 column with a gradient program from 50% to 90% methanol in ultrapure water. An external standard calibration curve (R2 = 0.9958) was established by plotting the ion m/z 163 [M+H]+ peak area versus the amount of analyte. The repeatability ranges between 11% and 2% at a concentration around 10 and 150 ng mL−1. The limit of detection was 10 ng mL−1 and the limit of quantification was 40 ng mL−1. Levoglucosan concentrations ranged from 10 to 718 ng mL−1 in the Muztagh Ata ice core and from 10 to 93 ng mL−1 in the Tanggula ice core. These concentrations, up to 1000 times higher than those measured in samples from Antarctic and Greenland, showed the higher vulnerability of the Tibetan Plateau glaciers to biomass burning events.

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