DSpace Collection:

Dominance of large-scale atmospheric circulations in long-term variations of winter PM10 concentrations over East Asia

2020-07-01T00:00:00Z

Title: Dominance of large-scale atmospheric circulations in long-term variations of winter PM10 concentrations over East Asia Authors: Lee, Greem; Ho, Chang-Hoi; Chang, Lim-Seok; Kim, Jinwon; Kim, Maeng-Ki; Kim, Seong-Joong Abstract: Concentrations of wintertime particulate matters of diameters below 10 mu m (PM10) in South Korea and China have decreased since the 2000s largely owing to the emissions reduction policies of the two countries; however, this decreasing tendency has been notably weakened, or even been reversed, in recent years. This study examines the influence of large-scale atmospheric circulations on this PM10, change over East Asia for the winters (December-February) of the 2004/05-2015/16 period using an empirical orthogonal function (EOF) analysis. The first EOF mode, which accounts for 32.7% of the total variance, indicates decreases in PM10, concentrations until 2012 and thereafter increases in them particularly at most stations in eastern and northeastern China. Regression patterns of meteorological variables with respect to the first EOF time series indicate that the wintertime PM10, variations over East Asia are greatly influenced by the Ural blocking; the weakening of the Ural blocking after 2014 led to the weakening of cold air flows from the north and provided atmospheric conditions favorable for bad air quality events over East Asia. The second EOF mode, which accounts for 20.1% of the total variance, shows a similar spatial distribution as the linear trend of PM10, concentrations during the analysis period and would be related to the long-term changes in emissions. Our findings emphasize that the long-term variations in air quality over East Asia are affected primarily by the variations in large-scale atmospheric circulations with secondary contributions from the changes in emissions.

Storm Induced Air-Ice-Sea Interactions in a DramaticallyChanging Arctic Ocean

2020-04-01T00:00:00Z

Title: Storm Induced Air-Ice-Sea Interactions in a DramaticallyChanging Arctic Ocean Authors: Xiangdong Zhang

Development and Application of the Korea Polar Prediction System (KPOPS) for Climate Change and Disastrous Weather Events

2020-02-28T00:00:00Z

Title: Development and Application of the Korea Polar Prediction System (KPOPS) for Climate Change and Disastrous Weather Events Authors: Kim, Joo-Hong

Arctic ship-based evidence of new particle formation events in the Chukchi and East Siberian Seas

2020-02-01T00:00:00Z

Title: Arctic ship-based evidence of new particle formation events in the Chukchi and East Siberian Seas Authors: Dall'Osto, M.; Park, J.; Kim, Joo-Hong; Kang, Sung-Ho; Park, Kihong; Beddows, D.C.S.; Harrison, Roy M.; Yoon, Young Jun Abstract: Arctic aerosol-climate interactions are controlled by multiple factors including sources, processes and removal mechanisms of particles. The Arctic is mostly ocean, surrounded by mostly land, and our understanding of Arctic aerosol processes is incomplete due to scarce measurements carried out in sea ice regions. In particular, it is currently not known if these particular regions are sources of aerosols of primary or secondary origin. We present new results from ship-based measurements illustrating that marine new particle production and growth events occur in open ocean and melting sea ice regions in the Chukchi and East Siberian Seas. We report two new particle formation events during which a recently formed nucleation mode (<15 nm diameter) is detected and is observed to slowly grow into an Aitken mode (0.1-3.8 nm/h). Our results suggest that new particle formation occurs in the marine boundary layer contributing to the Arctic aerosol population in the study region for the first time studied and herein reported.