Composite differences of wind vector (m/s) and geopotential height (gpm; shaded) at 500 hPa during March and April for the 5 years of highest and of lowest Asian dust years over South Korea. Positive (red) and negative (blue) values represent higher and lower geopotential height anomalies, respectively.

Sunyoung Kim, Eungul Lee, and Seungho Lee explored the transporting processes for the Asian dust observed over South Korea. The frequency of Asian dust days (ADDs) were used to analyze the associations of the ADDs with land surface conditions over the four source regions, including inner-Mongolia, the Gobi Desert, Manchuria, and Loess Plateau, and atmospheric synoptic variables over central and eastern Asia. Precipitation and Palmer Drought Severity Index (PDSI) inthe source regions during the previous summer were negatively correlated with the ADDs in South Korea. Statistically and physically more significant processes were found in the associations of atmospheric synoptic conditions with the ADDs. The intensified winds of northwesterly-northerly-northwesterly over a pathway of the Asian dust from the source regions to South Korea were identified during high ADDs years in South Korea. A dipole pattern of anti-cyclonic and cyclonic anomalies over central and eastern Asia, respectively, supported the Asian dust pathway.

The identified mechanisms of Asian dust movement could contribute to enhance the predictive skill of the Asian dust prediction model, which has been performed mainly by weather variables in the source regions and large-scale climate indices in the previous studies.

Publications

Kim, S, E. Lee*, and S. Lee (2019), Effects of land surface and atmospheric conditions on the Asian dust observed over South Korea, Int. J. Climatol. 14 (1), 33-45. [Link] (* Corresponding author).

Funding sources

National Research Foundation of Korea Grant (NRF-2013S1A3A2052995).