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| Titel |
Aerosol optical depth and its relation to regional-scale circulations over Korea during MAPS-Seoul (May-June, 2015) and KORUS-AQ campaigns (May-June, 2016) |
| VerfasserIn |
Hyunhye Yoon, Sang-Woo Kim, Ji-Hyoung Kim, Jin-Soo Park, Joon-Young Ahn, Jae-Bum Lee, Yong-Jae Lim |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250147569
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| Publikation (Nr.) |
 EGU/EGU2017-11752.pdf |
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| Zusammenfassung |
| We investigate aerosol optical depth (AOD) and its relation to regional-scale circulations over
Korea during the two recent field campaigns conducted in May-June of 2015 (MAPS-Seoul
experiment) and May-June of 2016 (KORUS-AQ campaign), using satellite MODIS and
AERONET measurement data. The monthly averaged MODIS AOD at 550 nm was estimated
to about 0.35 in May and 0.50 in June during the MAPS-Seoul experiment, which was about
33% and 17% lower than that of 13-year averaged MODIS AOD. MODIS AOD during
KORUS-AQ 2016 campaign was similarly about 8∼23% lower than those of 13-year
averages, but slightly higher than those in 2015. The monthly averaged MODIS AOD was
0.40 in May and 0.56 in June, 2016. Consistently, ground-based AERONET sky
radiometer measurements at Seoul showed AODs of about 0.35 (May) and 0.60
(June) at 500 nm during MAPS-Seoul experiment, which was approximately 32%
and 20% lower than the averaged AODs (May – 0.51; June – 0.76) from 4-year
measurements (2012, 2013, 2015, and 2016). Also, AOD during KORUS-AQ campaign in
2016 was about 0.43 in May and 0.71 in June, which was about 16% and 6% lower
than 4-year mean AOD. This year-to-year variation of AOD in May-June over East
Asia, including Korea, was closely linked with synoptic atmospheric circulations.
Generally, aerosol optical depth (AOD) is high in May and June due to stagnant
synoptic meteorological systems, as previously reported by Kim et al. (Atmospheric
Environment, 2007). For example, in 2012, MODIS AOD over the Korean Peninsula was
observed to be about 0.71 in May and 0.72 in June. This can be explained by the
frequent occurrences of stagnant atmospheric conditions. However, the regional-scale
circulations during MAPS-Seoul and KORUS-AQ campaigns were characterized
by the fast-moving confluent flows over the Korean peninsula, formed between
Siberian high pressure system located in North China and North Pacific high in South
China. These results suggest that atmospheric circulations play a crucial role in
atmospheric aerosol loadings in East Asia, especially over the Korean Peninsula
during pre-monsoon period (May-June), before the onset of summer rainy monsoon. |
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