Impacts of atmospheric vertical structures on transboundary aerosol transport from China to South Korea

Lee, Hyo‐Jung; Jo, Hyun‐Young; Kim, Sang Woo; Park, Moon Soo; Kim, Cheol-Hee

doi:10.1038/s41598-019-49691-z

Cited by 47 publications

(27 citation statements)

References 33 publications

(20 reference statements)

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“…Spatially, we focused on two regions as representative examples: Seoul and the Gyeonggi province (SG), which is in the center of South Korea, and Daegu and the Gyeongbuk province (DG), which had the biggest number of COVID-19 confirmed cases during the research time period. Since the air quality in the Korean peninsula is strongly affected by the transboundary transport of air pollutants from China 27 , 28 , we also simultaneously investigated the air quality pattern in 4 provinces of eastern China (Liaoning, Hebei, Shandong, and Jiangsu) (Fig. S2 ).…”

Section: Resultsmentioning

confidence: 99%

The implication of the air quality pattern in South Korea after the COVID-19 outbreak

Koo

Kim

Lee

et al. 2020

Sci Rep

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By using multiple satellite measurements, the changes of the aerosol optical depth (AOD) and nitrogen dioxide (NO2) over South Korea were investigated from January to March 2020 to evaluate the COVID-19 effect on the regional air quality. The NO2 decrease in South Korea was found but not significant, which indicates the effects of spontaneous social distancing under the maintenance of ordinary life. The AODs in 2020 were normally high in January, but they became lower starting from February. Since the atmosphere over Eastern Asia was unusually stagnant in January and February 2020, the AOD decrease in February 2020 clearly reveals the positive effect of the COVID-19. Considering the insignificant NO2 decrease in South Korea and the relatively long lifetime of aerosols, the AOD decrease in South Korea may be more attributed to the improvement of the air quality in neighboring countries. In March, regional atmosphere became well mixed and ventilated over South Korea, contributing to large enhancement of air quality. While the social activity was reduced after the COVID-19 outbreak, the regional meteorology should be also examined significantly to avoid the biased evaluation of the social impact on the change of the regional air quality.

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Section: Resultsmentioning

confidence: 99%

The implication of the air quality pattern in South Korea after the COVID-19 outbreak

Koo

Kim

Lee

et al. 2020

Sci Rep

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“…On top of CO data assimilation, improved emissions through state augmentation can help improve the next generation of Korean (e.g., Lee et al, 2020) or global (Barré et al, 2019) air quality analysis and forecasting systems. Further improvements can be achieved by simultaneously assimilating CH 2 O retrievals (e.g., Souri et al, 2020) and CO retrievals.…”

Section: Discussionmentioning

confidence: 99%

Correcting model biases of CO in East Asia: impact on oxidant distributions during KORUS-AQ

et al. 2020

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Abstract. Global coupled chemistry–climate models underestimate carbon monoxide (CO) in the Northern Hemisphere, exhibiting a pervasive negative bias against measurements peaking in late winter and early spring. While this bias has been commonly attributed to underestimation of direct anthropogenic and biomass burning emissions, chemical production and loss via OH reaction from emissions of anthropogenic and biogenic volatile organic compounds (VOCs) play an important role. Here we investigate the reasons for this underestimation using aircraft measurements taken in May and June 2016 from the Korea–United States Air Quality (KORUS-AQ) experiment in South Korea and the Air Chemistry Research in Asia (ARIAs) in the North China Plain (NCP). For reference, multispectral CO retrievals (V8J) from the Measurements of Pollution in the Troposphere (MOPITT) are jointly assimilated with meteorological observations using an ensemble adjustment Kalman filter (EAKF) within the global Community Atmosphere Model with Chemistry (CAM-Chem) and the Data Assimilation Research Testbed (DART). With regard to KORUS-AQ data, CO is underestimated by 42 % in the control run and by 12 % with the MOPITT assimilation run. The inversion suggests an underestimation of anthropogenic CO sources in many regions, by up to 80 % for northern China, with large increments over the Liaoning Province and the North China Plain (NCP). Yet, an often-overlooked aspect of these inversions is that correcting the underestimation in anthropogenic CO emissions also improves the comparison with observational O3 datasets and observationally constrained box model simulations of OH and HO2. Running a CAM-Chem simulation with the updated emissions of anthropogenic CO reduces the bias by 29 % for CO, 18 % for ozone, 11 % for HO2, and 27 % for OH. Longer-lived anthropogenic VOCs whose model errors are correlated with CO are also improved, while short-lived VOCs, including formaldehyde, are difficult to constrain solely by assimilating satellite retrievals of CO. During an anticyclonic episode, better simulation of O3, with an average underestimation of 5.5 ppbv, and a reduction in the bias of surface formaldehyde and oxygenated VOCs can be achieved by separately increasing by a factor of 2 the modeled biogenic emissions for the plant functional types found in Korea. Results also suggest that controlling VOC and CO emissions, in addition to widespread NOx controls, can improve ozone pollution over East Asia.

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“…The average altitude of the Seoul data was 245 ± 126 m. Average atmospheric boundary layer heights in the Seoul region during spring, 2016 were 548 ± 180 m at night and 1182 ± 540 m during the day (H.-J. Lee et al, 2019). The earliest Seoul sample was collected at 7:40 a.m. Local Standard Time (LST), about 2 hours after sunrise, and the latest at 4:10 p.m.…”

Section: Selection and Overview Of Seoul Datamentioning

confidence: 99%

Characterization, sources and reactivity of volatile organic compounds (VOCs) in Seoul and surrounding regions during KORUS-AQ

Simpson

Blake

et al. 2020

Elem Sci Anth

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The Korea-United States Air Quality Study (KORUS-AQ) took place in spring 2016 to better understand air pollution in Korea. In support of KORUS-AQ, 2554 whole air samples (WAS) were collected aboard the NASA DC-8 research aircraft and analyzed for 82 C 1-C 10 volatile organic compounds (VOCs) using multi-column gas chromatography. Together with fast-response measurements from other groups, the air samples were used to characterize the VOC composition in Seoul and surrounding regions, determine which VOCs are major ozone precursors in Seoul, and identify the sources of these reactive VOCs. (1) The WAS VOCs showed distinct signatures depending on their source origins. Air collected over Seoul had abundant ethane, propane, toluene and n-butane while plumes from the Daesan petrochemical complex were rich in ethene, C 2-C 6 alkanes and benzene. Carbonyl sulfide (COS), CFC-113, CFC-114, carbon tetrachloride (CCl 4) and 1,2-dichloroethane were good tracers of air originating from China. CFC-11 was also elevated in air from China but was surprisingly more elevated in air over Seoul. (2) Methanol, isoprene, toluene, xylenes and ethene were strong individual contributors to OH reactivity in Seoul. However methanol contributed less to ozone formation based on photochemical box modeling, which better accounts for radical chemistry. (3) Positive Matrix Factorization (PMF) and other techniques indicated a mix of VOC source influences in Seoul, including solvents, traffic, biogenic, and long-range transport. The solvent and traffic sources were roughly equal using PMF, and the solvents source was stronger in the KORUS-AQ emission inventory. Based on PMF, ethene and propene were primarily associated with traffic, and toluene, ethylbenzene and xylenes with solvents, especially non-paint solvents for toluene and paint solvents for ethylbenzene and xylenes. This suggests that VOC control strategies in Seoul could continue to target vehicle exhaust and paint solvents, with additional regulations to limit the VOC content in a variety of non-paint solvents.

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Impacts of atmospheric vertical structures on transboundary aerosol transport from China to South Korea

Cited by 47 publications

References 33 publications

The implication of the air quality pattern in South Korea after the COVID-19 outbreak

The implication of the air quality pattern in South Korea after the COVID-19 outbreak

Correcting model biases of CO in East Asia: impact on oxidant distributions during KORUS-AQ

Characterization, sources and reactivity of volatile organic compounds (VOCs) in Seoul and surrounding regions during KORUS-AQ

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