Review of Liu et al, Measurement report: Quantifying source contribution and radiative forcing of fossil fuel and biomass burning black carbon aerosol in the southeastern margin of Tibetan Plateau

Abstract. Black carbon (BC) aerosol plays a vital role in disturbing the balance of ecosystem and climate stability of Tibetan Plateau (TP). An intensive campaign was carried out from 14th March to 12th May 2018 in the southeastern margin of TP to investigate the sources of BC and their radiative effects. To do so, an improved aethalometer model was used to distinguish and apportion BC into fossil fuel combustion source and biomass burning source. To minimize the uncertainty associated with the aethalometer model, a receptor model coupling multi-wavelength absorption with chemical species was used to retrieve the site-dependent Ångström exponent (AAE) and BC mass absorption cross-section (MAC). The results show that the AAEs and BC MACs at wavelength of 880 nm were 0.9 and 12.3 m2 g−1 for fossil fuel source and 1.7 and 10.4 m2 g−1 for biomass burning, respectively. Based on these parameters, the fossil fuel source-related BC (BCfossil) was estimated 43 % of the total BC and the rest 57 % was from biomass burning (BCbiomass) during the campaign. The results from a regional chemical dynamical model reveal that high BCbiomass was contributed from the northeastern India and northern Burma, and the Southeast Asia can explain 40 % of BCbiomass. The high BCfossil was mainly identified from the southeast of sampling site. A radiative transfer model estimated that the atmospheric directive radiative forcing of BC was +4.6 ± 2.4 W m−2 on average, including +2.5 ± 1.8 W m−2 from BCbiomass, and +2.1 ± 0.9 W m−2 from BCfossil, which correspond to and heating rates of 0.07 ± 0.05 and 0.06 ± 0.02 K day−1, respectively. Our study will be useful for improving our understanding in BC sources on the TP and their climatic effect.

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Measurement report: quantifying source contribution of fossil fuels and biomass-burning black carbon aerosol in the southeastern margin of the Tibetan Plateau

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-973-2021 ◽

2021 ◽

Vol 21 (2) ◽

pp. 973-987

Author(s):

Huikun Liu ◽

Qiyuan Wang ◽

Li Xing ◽

Yong Zhang ◽

Ting Zhang ◽

...

Keyword(s):

Tibetan Plateau ◽

Southeast Asia ◽

Black Carbon ◽

Biomass Burning ◽

Fossil Fuels ◽

Anthropogenic Sources ◽

Transfer Model ◽

Transport Channel ◽

Source Contribution ◽

Southeastern Margin

Abstract. Anthropogenic emissions of black carbon (BC) aerosol are transported from Southeast Asia to the southwestern Tibetan Plateau (TP) during the pre-monsoon; however, the quantities of BC from different anthropogenic sources and the transport mechanisms are still not well constrained because there have been no high-time-resolution BC source apportionments. Intensive measurements were taken in a transport channel for pollutants from Southeast Asia to the southeastern margin of the TP during the pre-monsoon to investigate the influences of fossil fuels and biomass burning on BC. A receptor model that coupled multi-wavelength absorption with aerosol species concentrations was used to retrieve site-specific Ångström exponents (AAEs) and mass absorption cross sections (MACs) for BC. An “aethalometer model” that used those values showed that biomass burning had a larger contribution to BC mass than fossil fuels (BCbiomass=57 % versus BCfossil=43 %). The potential source contribution function indicated that BCbiomass was transported to the site from northeastern India and northern Burma. The Weather Research and Forecasting model coupled with chemistry (WRF-Chem) indicated that 40 % of BCbiomass originated from Southeast Asia, while the high BCfossil was transported from the southwest of the sampling site. A radiative transfer model indicated that the average atmospheric direct radiative effect (DRE) of BC was +4.6 ± 2.4 W m−2, with +2.5 ± 1.8 W m−2 from BCbiomass and +2.1 ± 0.9 W m−2 from BCfossil. The DRE of BCbiomass and BCfossil produced heating rates of 0.07 ± 0.05 and 0.06 ± 0.02 K d−1, respectively. This study provides insights into sources of BC over a transport channel to the southeastern TP and the influence of the cross-border transportation of biomass-burning emissions from Southeast Asia during the pre-monsoon.

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Impacts of Two East Asian Atmospheric Circulation Modes on Black Carbon Aerosol Over the Tibetan Plateau in Winter

Journal of Geophysical Research Atmospheres ◽

10.1029/2020jd032458 ◽

2020 ◽

Vol 125 (12) ◽

Author(s):

Tiangang Yuan ◽

Siyu Chen ◽

Lin Wang ◽

Yaoxian Yang ◽

Hongru Bi ◽

...

Keyword(s):

Tibetan Plateau ◽

Black Carbon ◽

Atmospheric Circulation ◽

East Asian ◽

The Tibetan Plateau ◽

Black Carbon Aerosol

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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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Source apportionment of black carbon (BC) from fossil fuel and biomass burning in metropolitan Milan, Italy

Atmospheric Environment ◽

10.1016/j.atmosenv.2019.02.009 ◽

2019 ◽

Vol 203 ◽

pp. 252-261 ◽

Cited By ~ 15

Author(s):

Amirhosein Mousavi ◽

Mohammad H. Sowlat ◽

Christopher Lovett ◽

Martin Rauber ◽

Soenke Szidat ◽

...

Keyword(s):

Black Carbon ◽

Source Apportionment ◽

Biomass Burning ◽

Fossil Fuel

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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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Black carbon aerosol quantification over north-west Himalayas: Seasonal heterogeneity, source apportionment and radiative forcing

Environmental Pollution ◽

10.1016/j.envpol.2019.113446 ◽

2020 ◽

Vol 257 ◽

pp. 113446 ◽

Cited By ~ 9

Author(s):

Yogesh Kant ◽

Darga Saheb Shaik ◽

Debashis Mitra ◽

H.C. Chandola ◽

S. Suresh Babu ◽

...

Keyword(s):

Black Carbon ◽

Source Apportionment ◽

Radiative Forcing ◽

North West ◽

Black Carbon Aerosol

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Black carbon in the atmosphere and snow, from pre-industrial times until present

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-6809-2011 ◽

2011 ◽

Vol 11 (14) ◽

pp. 6809-6836 ◽

Cited By ~ 89

Author(s):

R. B. Skeie ◽

T. Berntsen ◽

G. Myhre ◽

C. A. Pedersen ◽

J. Ström ◽

...

Keyword(s):

Black Carbon ◽

Radiative Forcing ◽

Fossil Fuel ◽

The Arctic ◽

Slight Reduction ◽

Snow Albedo ◽

Aerosol Effect ◽

Albedo Effect ◽

Concentration Changes ◽

Global Mean

Abstract. The distribution of black carbon (BC) in the atmosphere and the deposition of BC on snow surfaces since pre-industrial time until present are modelled with the Oslo CTM2 model. The model results are compared with observations including recent measurements of BC in snow in the Arctic. The global mean burden of BC from fossil fuel and biofuel sources increased during two periods. The first period, until 1920, is related to increases in emissions in North America and Europe, and the last period after 1970 are related mainly to increasing emissions in East Asia. Although the global burden of BC from fossil fuel and biofuel increases, in the Arctic the maximum atmospheric BC burden as well as in the snow was reached in 1960s, with a slight reduction thereafter. The global mean burden of BC from open biomass burning sources has not changed significantly since 1900. With current inventories of emissions from open biomass sources, the modelled burden of BC in snow and in the atmosphere north of 65° N is small compared to the BC burden of fossil fuel and biofuel origin. From the concentration changes radiative forcing time series due to the direct aerosol effect as well as the snow-albedo effect is calculated for BC from fossil fuel and biofuel. The calculated radiative forcing in 2000 for the direct aerosol effect is 0.35 W m−2 and for the snow-albedo effect 0.016 W m−2 in this study. Due to a southward shift in the emissions there is an increase in the lifetime of BC as well as an increase in normalized radiative forcing, giving a change in forcing per unit of emissions of 26 % since 1950.

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Modelled black carbon radiative forcing and atmospheric lifetime in AeroCom Phase II constrained by aircraft observations

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-12465-2014 ◽

2014 ◽

Vol 14 (22) ◽

pp. 12465-12477 ◽

Cited By ~ 108

Author(s):

B. H. Samset ◽

G. Myhre ◽

A. Herber ◽

Y. Kondo ◽

S.-M. Li ◽

...

Keyword(s):

Black Carbon ◽

Phase Ii ◽

Radiative Forcing ◽

Fossil Fuel ◽

Global Climate ◽

Aircraft Measurement ◽

Atmospheric Lifetime ◽

Range Transport ◽

Aircraft Observations ◽

Measurement Campaigns

Abstract. Atmospheric black carbon (BC) absorbs solar radiation, and exacerbates global warming through exerting positive radiative forcing (RF). However, the contribution of BC to ongoing changes in global climate is under debate. Anthropogenic BC emissions, and the resulting distribution of BC concentration, are highly uncertain. In particular, long-range transport and processes affecting BC atmospheric lifetime are poorly understood. Here we discuss whether recent assessments may have overestimated present-day BC radiative forcing in remote regions. We compare vertical profiles of BC concentration from four recent aircraft measurement campaigns to simulations by 13 aerosol models participating in the AeroCom Phase II intercomparison. An atmospheric lifetime of BC of less than 5 days is shown to be essential for reproducing observations in remote ocean regions, in line with other recent studies. Adjusting model results to measurements in remote regions, and at high altitudes, leads to a 25% reduction in AeroCom Phase II median direct BC forcing, from fossil fuel and biofuel burning, over the industrial era. The sensitivity of modelled forcing to BC vertical profile and lifetime highlights an urgent need for further flight campaigns, close to sources and in remote regions, to provide improved quantification of BC effects for use in climate policy.

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