Long-range transport of aerosols from East and Southeast Asia to northern Philippines and its direct radiative forcing effect

Abstract. This study analyzes mechanisms of long-range transport of aerosol and aerosol chemical characteristics in and around East and Southeast Asia. Ground-based size-resolved aerosol measurements collected at the Manila Observatory in Metro Manila, Philippines from July–October 2018 were used to identify and contrast high and low aerosol loading events. Multiple data sources, including models, remote-sensing, and in situ measurements, are used to analyze the impacts of long-range aerosol transport on Metro Manila and the conditions at the local and synoptic scales facilitating this transport. Evidence of long-range transport of biomass burning aerosol from the Maritime Continent was identified through model results and the presence of biomass burning tracers (e.g. K, Rb) in the ground-based measurements. The impacts of emissions transported from continental East Asia are also identified; for one of the events analyzed, this transport was facilitated by the nearby passage of a typhoon. Changes in the aerosol size distributions, water-soluble chemical composition, and contributions of various organic aerosol species to the total water-soluble organic aerosol were examined for the different cases. The events impacted by biomass burning transport had the overall highest concentration of water-soluble organic acids, while the events impacted by long-range transport from continental East Asia, showed high percent contributions from shorter chain dicarboxylic acids (i.e. oxalate) that are often representative of photochemical and aqueous processing in the atmosphere. The low aerosol loading event was subject to a larger precipitation accumulation than the high aerosol events, indicative of wet scavenging as an aerosol sink in the study region. This low aerosol event was characterized by a larger relative contribution from supermicrometer aerosols and had a higher percent contribution from longer-chain dicarboxylic acids (i.e. maleate) to the water-soluble organic aerosol fraction. Results of this study have implications for better understanding of the transport and chemical characteristics of aerosol in a highly-populated region that has thus far been difficult to measure through remote-sensing methods. Furthermore, findings associated with the effects of air mass mixing on aerosol physiochemical properties are applicable to other global regions impacted by both natural and anthropogenic sources.

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Modelling of long-range transport of Southeast Asia biomass-burning aerosols to Taiwan and their radiative forcings over East Asia

Tellus B ◽

10.3402/tellusb.v66.23733 ◽

2014 ◽

Vol 66 (1) ◽

pp. 23733 ◽

Cited By ~ 19

Author(s):

Chuan-Yao Lin ◽

Chun Zhao ◽

Xiaohong Liu ◽

Neng-Huei Lin ◽

Wei-Nei Chen

Keyword(s):

Southeast Asia ◽

East Asia ◽

Long Range ◽

Biomass Burning ◽

Long Range Transport ◽

Radiative Forcings ◽

Range Transport

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Interannual variability of long-range transport as seen at the Mt. Bachelor Observatory

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-8-16335-2008 ◽

2008 ◽

Vol 8 (4) ◽

pp. 16335-16379 ◽

Cited By ~ 3

Author(s):

D. R. Reidmiller ◽

D. A. Jaffe ◽

D. Chand ◽

S. Strode ◽

P. Swartzendruber ◽

...

Keyword(s):

Southeast Asia ◽

Interannual Variability ◽

Long Range ◽

Biomass Burning ◽

Transport Model ◽

Long Range Transport ◽

Naval Research ◽

Chemical Transport Model ◽

Northeast Pacific ◽

Range Transport

Abstract. Interannual variations in background tropospheric trace gases (such as carbon monoxide, CO) are largely driven by variations in emissions (especially wildfires), transport pathways and tropospheric oxidizing capacity. Understanding this variability is essential to quantify the intercontinental contribution to US air quality. We investigate the interannual variability of long-range transport of Asian pollutants to the Northeast Pacific via measurements from the Mt. Bachelor Observatory (MBO: 43.98° N, 121.69° W; 2.7 km above sea level) and GEOS-Chem chemical transport model simulations in spring 2005 vs. the INTEX-B campaign during spring 2006. Measurements of CO at MBO were significantly enhanced during spring 2005 relative to the same time in 2006 (the INTEX-B study period); a monthly mean decline in CO of 41 ppbv was observed between April 2005 and April 2006. Meteorological indices show that long-range transport of CO from the heavily industrialized region of East Asia was significantly greater in 2005 than in 2006. In addition, spring 2005 was an anomalously strong biomass burning season in Southeast Asia. Data presented by Yurganov et al. (2008) using MOPITT satellite retrievals from this area reveal an average CO burden anomaly (referenced to March 2000–February 2002 mean values) between October 2004 through April 2005 of 2.6 Tg CO vs. 0.6 Tg CO for the same period a year later. The Naval Research Laboratory's global aerosol transport model shows that emissions from these fires were efficiently transported to MBO throughout April 2005. Asian dust transport, however, was substantially greater in 2006 than 2005, particularly in May. Monthly mean aerosol light scattering coefficient at 532 nm (σsp) at MBO more than doubled from 2.7 Mm−1 in May 2005 to 6.2 Mm−1 in May 2006. We also evaluate CO interannual variability throughout the western US via Earth System Research Laboratory ground site data and throughout the Northern Hemisphere via MOPITT and TES satellite observations. Both in the Northeast Pacific and on larger scales, we reveal a significant decrease (from 2–21%) in springtime maximum CO between 2005 and 2006, evident in all platforms and the GEOS-Chem model. We attribute this to (a) anomalously strong biomass burning in Southeast Asia during winter 2004 through spring 2005, and (b) the transport pattern in 2006 which limited the inflow of Asian pollution to the lower free troposphere over western North America.

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Evaluating the influences of biomass burning during 2006 BASE-ASIA: a regional chemical transport modeling

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-3837-2012 ◽

2012 ◽

Vol 12 (9) ◽

pp. 3837-3855 ◽

Cited By ~ 57

Author(s):

J. S. Fu ◽

N. C. Hsu ◽

Y. Gao ◽

K. Huang ◽

C. Li ◽

...

Keyword(s):

Southeast Asia ◽

East Asia ◽

Long Range ◽

Biomass Burning ◽

Cross Sections ◽

Southern China ◽

Source Region ◽

Long Range Transport ◽

Range Transport ◽

The Impact

Abstract. To evaluate the impact of biomass burning from Southeast Asia to East Asia, this study conducted numerical simulations during NASA's 2006 Biomass-burning Aerosols in South-East Asia: Smoke Impact Assessment (BASE-ASIA). Two typical episode periods (27–28 March and 13–14 April) were examined. Two emission inventories, FLAMBE and GFED, were used in the simulations. The influences during two episodes in the source region (Southeast Asia) contributed to the surface CO, O3 and PM2.5 concentrations as high as 400 ppbv, 20 ppbv and 80 μg m−3, respectively. The perturbations with and without biomass burning of the above three species during the intense episodes were in the range of 10 to 60%, 10 to 20% and 30 to 70%, respectively. The impact due to long-range transport could spread over the southeastern parts of East Asia and could reach about 160 to 360 ppbv, 8 to 18 ppbv and 8 to 64 μg m−3 on CO, O3 and PM2.5, respectively; the percentage impact could reach 20 to 50% on CO, 10 to 30% on O3, and as high as 70% on PM2.5. In March, the impact of biomass burning mainly concentrated in Southeast Asia and southern China, while in April the impact becomes slightly broader and even could go up to the Yangtze River Delta region. Two cross-sections at 15° N and 20° N were used to compare the vertical flux of biomass burning. In the source region (Southeast Asia), CO, O3 and PM2.5 concentrations had a strong upward transport from surface to high altitudes. The eastward transport becomes strong from 2 to 8 km in the free troposphere. The subsidence process during the long-range transport contributed 60 to 70%, 20 to 50%, and 80% on CO, O3 and PM2.5, respectively to surface in the downwind area. The study reveals the significant impact of Southeastern Asia biomass burning on the air quality in both local and downwind areas, particularly during biomass burning episodes. This modeling study might provide constraints of lower limit. An additional study is underway for an active biomass burning year to obtain an upper limit and climate effects.

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Interannual variability of long-range transport as seen at the Mt. Bachelor observatory

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-557-2009 ◽

2009 ◽

Vol 9 (2) ◽

pp. 557-572 ◽

Cited By ~ 27

Author(s):

D. R. Reidmiller ◽

D. A. Jaffe ◽

D. Chand ◽

S. Strode ◽

P. Swartzendruber ◽

...

Keyword(s):

Southeast Asia ◽

Interannual Variability ◽

Long Range ◽

Biomass Burning ◽

Transport Model ◽

Long Range Transport ◽

Naval Research ◽

Chemical Transport Model ◽

Northeast Pacific ◽

Range Transport

Abstract. Interannual variations in background tropospheric trace gases (such as carbon monoxide, CO) are largely driven by variations in emissions (especially wildfires) and transport pathways. Understanding this variability is essential to quantify the intercontinental contribution to US air quality. We investigate the interannual variability of long-range transport of Asian pollutants to the Northeast Pacific via measurements from the Mt. Bachelor Observatory (MBO: 43.98° N, 121.69° W; 2.7 km a.s.l.) and GEOS-Chem chemical transport model simulations in spring 2005 vs. the INTEX-B campaign during spring 2006. Measurements of CO at MBO were significantly enhanced during spring 2005 relative to the same time in 2006 (the INTEX-B study period); a decline in monthly mean CO of 41 ppbv was observed between April 2005 and April 2006. A backtrajectory-based meteorological index shows that long-range transport of CO from the heavily industrialized region of East Asia was significantly greater in early spring 2005 than in 2006. In addition, spring 2005 was an anomalously strong biomass burning season in Southeast Asia. Data presented by Yurganov et al. (2008) using MOPITT satellite retrievals from this area reveal an average CO burden anomaly (referenced to March 2000–February 2002 mean values) between October 2004 through April 2005 of 2.6 Tg CO vs. 0.6 Tg CO for the same period a year later. The Naval Research Laboratory's global aerosol transport model, as well as winds from NCEP reanalysis, show that emissions from these fires were efficiently transported to MBO throughout April 2005. Asian dust transport, however, was substantially greater in 2006 than 2005, particularly in May. Monthly mean aerosol light scattering coefficient at 532 nm (σsp) at MBO more than doubled from 2.7 Mm−1 in May 2005 to 6.2 Mm−1 in May 2006. We also evaluate CO interannual variability throughout the western US via Earth System Research Laboratory ground site data and throughout the Northern Hemisphere via MOPITT and TES satellite observations. Both in the Northeast Pacific and on larger scales, we reveal a significant decrease (from 2–21%) in springtime maximum CO between 2005 and 2006, evident in all platforms and the GEOS-Chem model. We attribute this to (a) anomalously strong biomass burning in Southeast Asia during winter 2004 through spring 2005, and (b) the transport pattern in March and April 2006 which limited the inflow of Asian pollution to the lower free troposphere over western North America.

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PCDD/F Measurement at a High-Altitude Station in Central Taiwan: Evaluation of Long-Range Transport of PCDD/Fs during the Southeast Asia Biomass Burning Event

Environmental Science & Technology ◽

10.1021/es1000984 ◽

2010 ◽

Vol 44 (8) ◽

pp. 2954-2960 ◽

Cited By ~ 26

Author(s):

Kai Hsien Chi ◽

Chuan-Yao Lin ◽

Chang-Feng Ou Yang ◽

Jia-Lin Wang ◽

Neng-Heui Lin ◽

...

Keyword(s):

Southeast Asia ◽

High Altitude ◽

Long Range ◽

Biomass Burning ◽

Long Range Transport ◽

Range Transport ◽

Central Taiwan

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Evaluating the influences of biomass burning during 2006 BASE-ASIA: a regional chemical transport modeling

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-32205-2011 ◽

2011 ◽

Vol 11 (12) ◽

pp. 32205-32243 ◽

Cited By ~ 1

Author(s):

J. S. Fu ◽

N. C. Hsu ◽

Y. Gao ◽

K. Huang ◽

C. Li ◽

...

Keyword(s):

Southeast Asia ◽

East Asia ◽

Long Range ◽

Biomass Burning ◽

Cross Sections ◽

Southern China ◽

Source Region ◽

Long Range Transport ◽

Range Transport ◽

The Impact

Abstract. To evaluate the impact of biomass burning from Southeast Asia to East Asia, this study conducted numerical simulations during NASA's 2006 Biomass-burning Aerosols in South-East Asia: Smoke Impact Assessment (BASE-ASIA). Two typical episode periods (27–28 March and 13–14 April) were examined. Two emission inventories, FLAMBE and GFED, were used in the simulations. The influences during two episodes in the source region (Southeast Asia) contributed to the surface CO, O3 and PM2.5 concentrations as high as 400 ppbv, 20 ppbv and 80 μg m−3, respectively. The perturbations with and without biomass burning of the above three species during the intense episodes were in the range of 10 to 60%, 10 to 20% and 30 to 70%, respectively. The impact due to long-range transport could spread over the southeastern parts of East Asia and could reach about 160 to 360 ppbv, 8 to 18 ppbv and 8 to 64 μg m−3 on CO, O3 and PM2.5, respectively; the percentage impact could reach 20 to 50% on CO, 10 to 30% on O3, and as high as 70% on PM2.5. In March, the impact of biomass burning was mainly concentrated in Southeast Asia and Southern China, while in April the impact becomes slightly broader, potentially including the Yangtze River Delta region. Two cross-sections at 15° N and 20° N were used to compare the vertical flux of biomass burning. In the source region (Southeast Asia), CO, O3 and PM2.5 concentrations had a strong upward transport from surface to high altitudes. The eastward transport becomes strong from 2 to 8 km in the free troposphere. The subsidence process during the long-range transport contributed 60 to 70%, 20 to 50%, and 80% to CO, O3 and PM2.5, respectively to surface in the downwind area. The study reveals the significant impact of Southeastern Asia biomass burning on the air quality in both local and downwind areas, particularly during biomass burning episodes. This modeling study might provide lower limit constraints. An additional study is underway for an active biomass burning year to obtain an upper limit and climate effects.

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Long-range transport of anthropogenic air pollutants into the marine air: insight into fine particle transport and chloride depletion on sea salts

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-17715-2021 ◽

2021 ◽

Vol 21 (23) ◽

pp. 17715-17726

Author(s):

Liang Xu ◽

Xiaohuan Liu ◽

Huiwang Gao ◽

Xiaohong Yao ◽

Daizhou Zhang ◽

...

Keyword(s):

East Asia ◽

Long Range ◽

Air Pollutants ◽

Radiative Forcing ◽

Eastern China ◽

Long Range Transport ◽

Anthropogenic Aerosols ◽

Range Transport ◽

Anthropogenic Air Pollutants ◽

Marine Air

Abstract. Long-range transport of anthropogenic air pollutants from East Asia can affect the downwind marine air quality during spring and winter. Long-range transport of continental air pollutants and their interaction with sea salt aerosol (SSA) significantly modify the radiative forcing of marine aerosols and influence ocean biogeochemical cycling. Previous studies poorly characterize variations of aerosol particles along with air mass transport from the continental edge to the remote ocean. Here, the research ship R/V Dongfanghong 2 traveled from the eastern China seas (ECS) to the northwestern Pacific Ocean (NWPO) to understand what and how air pollutants were transported from the highly polluted continental air to clean marine air in spring. A transmission electron microscope (TEM) was used to find the long-range transported anthropogenic particles and the possible Cl-depletion phenomenon of SSA in marine air. Anthropogenic aerosols (e.g., sulfur (S)-rich, S-soot, S-metal/fly ash, organic matter (OM)-S, and OM coating particles) were identified and dramatically declined from 87 % to 8 % by number from the ECS to remote NWPO. For the SSA aging, 87 % of SSA particles in the ECS were identified as fully aged, while the proportion of fully aged SSA particles in the NWPO decreased to 29 %. Our results highlight that anthropogenic acidic gases in the troposphere (e.g., SO2, NOx, and volatile organic compounds) could be transported to remote marine air and exert a significant impact on aging of SSA particles in the NWPO. The study shows that anthropogenic particles and gases from East Asia significantly perturb different aerosol chemistry from coastal to remote marine air. More attention should be given to the modification of SSA particles in remote marine areas due to the influence of anthropogenic gaseous pollutants.

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