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

2021 ◽  
Vol 21 (2) ◽  
pp. 973-987
Author(s):  
Huikun Liu ◽  
Qiyuan Wang ◽  
Li Xing ◽  
Yong Zhang ◽  
Ting Zhang ◽  
...  

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.

2020 ◽  
Author(s):  
Huikun Liu ◽  
Qiyuan Wang ◽  
Li Xing ◽  
Yong Zhang ◽  
Ting Zhang ◽  
...  

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.


2015 ◽  
Vol 15 (10) ◽  
pp. 5415-5428 ◽  
Author(s):  
R. Kumar ◽  
M. C. Barth ◽  
V. S. Nair ◽  
G. G. Pfister ◽  
S. Suresh Babu ◽  
...  

Abstract. This study examines differences in the surface black carbon (BC) aerosol loading between the Bay of Bengal (BoB) and the Arabian Sea (AS) and identifies dominant sources of BC in South Asia and surrounding regions during March–May 2006 (Integrated Campaign for Aerosols, Gases and Radiation Budget, ICARB) period. A total of 13 BC tracers are introduced in the Weather Research and Forecasting Model coupled with Chemistry to address these objectives. The model reproduced the temporal and spatial variability of BC distribution observed over the AS and the BoB during the ICARB ship cruise and captured spatial variability at the inland sites. In general, the model underestimates the observed BC mass concentrations. However, the model–observation discrepancy in this study is smaller compared to previous studies. Model results show that ICARB measurements were fairly well representative of the AS and the BoB during the pre-monsoon season. Elevated BC mass concentrations in the BoB are due to 5 times stronger influence of anthropogenic emissions on the BoB compared to the AS. Biomass burning in Burma also affects the BoB much more strongly than the AS. Results show that anthropogenic and biomass burning emissions, respectively, accounted for 60 and 37% of the average ± standard deviation (representing spatial and temporal variability) BC mass concentration (1341 ± 2353 ng m−3) in South Asia. BC emissions from residential (61%) and industrial (23%) sectors are the major anthropogenic sources, except in the Himalayas where vehicular emissions dominate. We find that regional-scale transport of anthropogenic emissions contributes up to 25% of BC mass concentrations in western and eastern India, suggesting that surface BC mass concentrations cannot be linked directly to the local emissions in different regions of South Asia.


2017 ◽  
Author(s):  
Ling Qi ◽  
Qinbin Li ◽  
Daven K. Henze ◽  
Hsien-Liang Tseng ◽  
Cenlin He

Abstract. We quantify source contributions to springtime (April 2008) surface black carbon (BC) in the Arctic by interpreting surface observations of BC at five receptor sites (Denali, Barrow, Alert, Zeppelin, and Summit) using a global chemical transport model (GEOS-Chem) and its adjoint. Contributions to BC at Barrow, Alert, and Zeppelin are dominated by Asian anthropogenic sources (40–43 %) before April 18 and by Siberian open biomass burning emissions (29–41 %) afterward. In contrast, Summit, a mostly free tropospheric site, has predominantly an Asian anthropogenic source contribution (24–68 %, with an average of 45 %). We compute the adjoint sensitivity of BC concentrations at the five sites during a pollution episode (April 20–25) to global emissions from March 1 to April 25. The associated contributions are the combined results of these sensitivities and BC emissions. Local and regional anthropogenic sources in Alaska are the largest anthropogenic sources of BC at Denali (63 %), and natural gas flaring emissions in the Western Extreme North of Russia (WENR) are the largest anthropogenic sources of BC at Zeppelin (26 %) and Alert (13 %). We find that long-range transport of emissions from Beijing-Tianjin-Hebei (also known as Jing-Jin-Ji), the biggest urbanized region in Northern China, contribute significantly (~ 10 %) to surface BC across the Arctic. On average it takes ~ 12 days for Asian anthropogenic emissions and Siberian biomass burning emissions to reach Arctic lower troposphere, supporting earlier studies. Natural gas flaring emissions from the WENR reach Zeppelin in about a week. We find that episodic, direct transport events dominate BC at Denali (87 %), a site outside the Arctic front, a strong transport barrier. The relative contribution of direct transport to surface BC within the Arctic front is much smaller (~ 50 % at Barrow and Zeppelin and ~ 10 % at Alert). The large contributions from Asian anthropogenic sources are predominately in the form of ‘chronic’ pollution (~ 40 % at Barrow and 65 % at Alert and 57 % at Zeppelin) on 1–2 month timescales. As such, it is likely that previous studies using 5- or 10-day trajectory analyses strongly underestimated the contribution from Asia to surface BC in the Arctic. Both finer temporal resolution of biomass burning emissions and accounting for the Wegener-Bergeron-Findeisen (WBF) process in wet scavenging improve the source attribution estimates.


2021 ◽  
Vol 270 ◽  
pp. 116195
Author(s):  
Junhua Yang ◽  
Zhenming Ji ◽  
Shichang Kang ◽  
Lekhendra Tripathee

2021 ◽  
Author(s):  
Sho Ohata ◽  
Makoto Koike ◽  
Atsushi Yoshida ◽  
Nobuhiro Moteki ◽  
Kouji Adachi ◽  
...  

Abstract. Vertical profiles of the mass concentration of black carbon (BC) were measured at altitudes up to 5 km during the PAMARCMiP aircraft-based field experiment conducted around the Northern Greenland Sea (Fram Strait) during March and April 2018, with operation base Station Nord (81.6° N, 16.7° W). Median BC mass concentrations in individual altitude ranges were 7–18 ng m–3 at standard temperature and pressure at altitudes below 4.5 km. These concentrations were systematically lower than previous observations in the Arctic in spring conducted by ARCTAS-A in 2008 and NETCARE in 2015 and similar to those observed during HIPPO3 in 2010. Column amounts of BC for altitudes below 5 km in the Arctic (> 66.5° N, COLBC), observed during the ARCTAS-A and NETCARE experiments were higher by factors of 4.2 and 2.7, respectively, than those of the PAMARCMiP experiment. These differences could not be explained solely by the different locations of the experiments. The year-to-year variation of COLBC values generally corresponded to that of biomass burning activities in northern high latitudes over western and eastern Eurasia. Furthermore, numerical model simulations estimated the year-to-year variation of contributions from anthropogenic sources to be smaller than 30–40 %. These results suggest that the year-to-year variation of biomass burning activities likely affected BC amounts in the Arctic troposphere in spring, at least in the years examined in this study. The year-to-year variations in BC mass concentrations were also observed at the surface at high Arctic sites Ny-Ålesund and Barrow, although their magnitudes were slightly lower than those in COLBC. Numerical model simulations in general successfully reproduced the observed COLBC values for PAMARCMiP and HIPPO3 (within a factor of 2), whereas they markedly underestimated the values for ARCTAS-A and NETCARE by factors of 3.7–5.8 and 3.3–5.0, respectively. Because anthropogenic contributions account for nearly all of the COLBC (82–98 %) in PAMARCMiP and HIPPO3, the good agreements between the observations and calculations for these two experiments suggest that anthropogenic contributions were generally well reproduced. However, the significant underestimations of COLBC for ARCTAS-A and NETCARE suggest that biomass burning contributions were underestimated. In this study, we also investigated plumes with enhanced BC mass concentrations, which were affected by biomass burning emissions, observed at 5 km altitude. Interestingly, the mass-averaged diameter of BC (core) and the shell-to-core diameter ratio of BC-containing particles in the plumes were generally not very different from those in other air sampled, which were considered to be mostly aged anthropogenic BC. These observations provide useful bases to evaluate numerical model simulations of the BC radiative effect in the Arctic region in spring.


2016 ◽  
Author(s):  
N. Evangeliou ◽  
Y. Balkanski ◽  
W. M. Hao ◽  
A. Petkov ◽  
R. P. Silverstein ◽  
...  

Abstract. In recent decades much attention has been given to the Arctic environment, where climate change is happening rapidly. Black carbon (BC) has been shown to be a major component of Arctic pollution that also affects the radiative balance. In the present study, we focused on how vegetation fires that occurred in Northern Eurasia during the period of 2002–2013 influenced the budget of BC in the Arctic. For simulating the transport of fire emissions from Northern Eurasia to the Arctic, we adopted BC fire emission estimates developed independently by GFED3 (Global Fire Emissions Database) and FEI-NE (Fire Emission Inventory – Northern Eurasia). Both datasets were based on fire locations and burned areas detected by MODIS (MODerate resolution Imaging Spectroradiometer) instruments on NASA's (National Aeronautics and Space Administration) Terra and Aqua satellites. Anthropogenic sources of BC were estimated using the MACCity (Monitoring Atmospheric Composition & Climate/megaCITY – Zoom for the ENvironment) emission inventory. During the 12-year period, an average area of 250,000 km2 yr−1 was burned in Northern Eurasia and the global emissions of BC ranged between 8.0 and 9.5 Tg yr−1. For the BC emitted in the Northern Hemisphere, about 70 % originated from anthropogenic sources and the rest from biomass burning (BB). Using the FEI-NE inventory, we found that 102 ± 29 kt yr−1 BC from biomass burning was deposited on the Arctic (defined here as the area north of 67º N) during the 12 years simulated, which was twice as much as when using MACCity inventory (56 ± 8 kt yr−1). The annual mass of BC deposited in the Arctic from all sources (FEI-NE in Northern Eurasia, MACCity elsewhere) is significantly higher by about 37 % in 2009 to 181 % in 2012, compared to the BC deposited using just the MACCity emission inventory. Deposition of BC in the Arctic from BB sources in the Northern Hemisphere thus represents 68 % of the BC deposited from all BC sources (the remaining being due to anthropogenic sources). Northern Eurasian vegetation fires (FEI-NE) contributed 85 % (79–91 %) to the BC deposited over the Arctic from all BB sources in the Northern Hemisphere. Arctic total BC burden showed strong seasonal variations, with highest values during the Arctic Haze season. High winter–spring values of BC burden were caused by transport of BC mainly from anthropogenic sources in Europe, whereas the peak in summer was mainly due to the fire emissions in Northern Eurasia. BC particles emitted from fires in lower latitudes (35° N–40° N) were found to remain the longest in the atmosphere due to the high release altitudes of smoke plumes, exhibit tropospheric transport resulting in a high summer peak of burden, and grow by condensation processes. In regards to the geographic contribution on the deposition of BC, we estimated that about 46 % of the BC deposited over the Arctic from vegetation fires in Northern Eurasia originated from Siberia, 6 % from Kazakhstan, 5 % from Europe, and about 1 % from Mongolia. The remaining 42 % originated from other areas in Northern Eurasia. For spring and summer, we computed that 42 % of the BC released from Northern Eurasian vegetation fires was deposited over the Arctic (annual average: 17 %). Vegetation fires in Northern Eurasia contributed to 14 % to 57 % of BC surface concentrations at the Arctic stations (Alert, Barrow, Zeppelin, Villum, and Tiksi), with fires in Siberia contributing the largest share. However, anthropogenic sources in the Northern Hemisphere remain essential, contributing 29 % to 54 % to the surface concentrations at the Arctic monitoring stations. The rest originated from North American fires.


Sign in / Sign up

Export Citation Format

Share Document