Orographic‐Induced Strong Wind Associated With a Low‐Pressure System Under Clear‐Air Condition During ICE‐POP 2018. Issue 13 (30th June 2022)

• Record Type: Journal Article
• Authors: Tsai, Chia‐Lun; Kim, Kwonil; Liou, Yu‐Chieng; Kim, Jung‐Hoon; Lee, YongHee; Lee, GyuWon
• Is Part Of: Journal of geophysical research. Volume 127:Issue 13(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-06-30
• Subjects: strong wind -- clear‐air -- Doppler lidar -- WISSDOM -- pressure gradient force -- channel effect; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1029/2021JD036418
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: A strong wind event under clear‐air conditions during the 2018 Winter Olympic and Paralympic games in Pyeongchang, Korea, was examined using various datasets. High spatiotemporal resolution wind information was obtained by Doppler lidars, automatic weather stations, wind profiler, sounding observations, reanalysis datasets under the International Collaborative Experiments for Pyeongchang 2018 Olympic and Paralympic winter games (ICE‐POP 2018). This study aimed to understand the possible mechanisms of localized strong winds across a high mountainous area and on the leeside associated with the underlying large‐scale pattern of a low‐pressure system (LPS). The evolution of surface winds shows quite different patterns, exhibiting intensification of strong winds in the leeside and periodically persistent strong winds in upstream mountainous areas with the approaching LPS. The surface wind speed was intensified from ∼3 to ∼12 m s −1 (gusts were stronger than 20 m s −1 above the ground) at a surface station in the leeside. A budget analysis of the horizontal momentum equation suggested that the pressure gradient force (PGF) contributed from adiabatic warming and the passage of LPS was the main factor in the acceleration of the surface wind in the leeward side of the mountains. The detailed 3D winds revealed that the PGF also modulated the background winds at the mountainous station, which caused persistent strong and periodic winds (range of ∼7 to ∼12 m s −1 ) related to the channeling effect. The evidence showed that under the same synoptic condition of a LPS, different mechanisms are important for strong winds in determining the strength and persistence of orographic‐induced strong winds under clear‐air conditions. Plain Language Summary: This study examines a strong downslope wind event during ICE‐POP 2018 using Doppler lidars, and various datasets. The 3D winds can be well retrieved, and this is first time to document the mechanisms of strong wind in observational aspect under clear‐air conditions. The pressure gradient force causing by adiabatic warming and channeling effect are key factors to dominate the strong wind. The values of this study are improving our understanding and increasing the predictability of strong wind in Korea. Key Points: A low‐pressure system (LPS) dominated the nature of orographic‐induced strong winds under clear‐air conditions High‐resolution wind fields can be well retrieved by 3D Doppler wind synthesis via "WISSDOM" The effects of pressure gradient force associated with the LPS as well as adiabatic warming and channeling effect are key factors dominating the strong winds