Preliminary Analysis of Three-Dimensional Wind over Complex Terrain in South Korea Using Multiple-Doppler Radar Observations

This study utilized WISSDOM (Wind Synthesis System using Doppler Measurements) to analyze a case of low pressure system passed over Korea peninsula on 1 July 2016. Multiple radars and dense automatic weather system (AWS) are used to derive three-dimensional (3-D) wind via the WISSDOM. It is the first time adopted six ground-based radars to synthesize 3-D wind filed over complicated terrain in Pyeongchang (studied area) in South Korea. Although more uniform southwesterly in the studied area was conducted by circulations of the low pressure system, significant variations of fine scale wind and precipitation structures still can be recognized successfully by the WISSDOM. The main features of topography in studied area was characterized by northwest-southeast orientation of mountain ranges and two branches of ranges toward the southwest with gentle (relatively steep) slope on northern (southern) branch, and a valley just located between these branches. The results of the WISSDOM synthesis indicated that enhanced precipitation concentrated on windward side (near mountain crest) of the northern (southern) branch. Relatively weak (stronger) southwesterly exceeding 20 m s^-1 (~28 m s^-1) was observed on northern (southern) branch. Except for different gradient of slope of these two branches, wind speed would be a factor to dominated distributions of precipitation. Furthermore, the strongest southwesterly wind (exceeding ~28 m s^-1) was observed along the northern valley as it was forced possibly by channeling effect. In particular, the enhanced precipitation existed exactly near south part of the northern branch because of upward vertical velocity (~ 2 m s^-1) were trigged efficiently associated with this intensive valley wind.

Acknowledgments. This research was supported by a grant (17AWMP-B079625-04) from Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.