Development Processes of the East Asian Cyclones over the Korean Peninsula

Abstract

Abstract. The development processes of the extratropical cyclones passing the Korean Peninsula during the period of 1979–2017 are quantitatively evaluated in the potential vorticity (PV) perspective. A feature tracking algorithm is applied to the ERA-Interim reanalysis data to objectively identify the distinct northern- and southern-track (NT and ST) cyclones affecting the region in the cold season. The dynamic and thermodynamic contributions to the development of these two categories of cyclones are then comparatively assessed in terms of the relative vorticity tendency resulting from the PV tendency inversion. It is quantified through inversion that the NT cyclones develop 87.9 % dynamically and 6.2 % thermodynamically. In contrast, the respective contributions to the ST cyclones are 71.8 % and 43.5 % for the ST cyclones, with negative effects from non-explicit processes. In both NT and ST cyclones, the zonal PV advection in the upper troposphere is the most influential for the dynamic development, while nonlinear advection being more important in the former. The larger thermodynamic contribution of the latter is attributed to more latent heating being involved in the development, which produces more lower-level PV and reduces damping from vertical PV advection. These results indicate that East Asian cyclones passing the Korean Peninsula have different development processes depending on their tracks.

A Multi‐Inventory Ensemble Analysis of the Effects of Atmospheric Rivers on Precipitation and Streamflow in the Namgang‐Dam Basin in Korea

“…The AR storms account for 54% of storms annually and outnumber the non‐AR storms in the early part of the year (February‐August) while the non‐AR storms are more frequent in the latter part of the year (September–January). The annual cycle of AR‐storm frequency is thought to be related to the seasonal cycle of the large‐scale circulation and related ETC activities around Korea and EA (Kamae, Mei, Xie, Naoi, & Ueda, 2017; Kang & Son, 2021; Kim et al., 2021; Park et al., 2021a) because over 80% of ARs are accompanied by ETCs (Zhang et al., 2019). The increase in AR frequencies and ETCs in late spring and early summer can be related to the northward movement of the EA monsoon as moist processes are critical in developing ETCs around Korea (Kang et al., 2018; Park et al., 2021b).…”

“…Progresses in objective identification of ARs using gridded atmospheric data have facilitated analyzing ARs and their hydrological impacts in regions around the world other than WNA and WEU (Blamey et al., 2018; Bozkurt et al., 2021; Esfandiari & Lashkari, 2020; Gorodetskaya et al., 2014; Kamae, Mei, & Xie, et al., 2017; Kamae, Mei, Xie, Naoi, & Ueda, 2017; Kim et al., 2021; Mahoney et al., 2016; Moore et al., 2012; Massoud et al., 2020; Mundhenk et al., 2016; Park et al., 2021a; Ramos et al., 2015, 2018; Sharma & Déry, 2020b; Stohl et al., 2008; Viale et al., 2018; Ye et al., 2020). For East Asia (EA), previous studies (Kamae, Mei, Xie, Naoi, & Ueda, 2017; Kim et al., 2021; Park et al., 2021a) related the seasonal cycle of the AR frequency to the seasonal variations of the large‐scale circulation and related ETC activities around Korea and EA as ETC activities over EA substantially increase in spring and early summer, the period of the northward march of the EA monsoon rainfall, then rapidly decrease from July to August (Kang et al., 2018; Kang & Son, 2021). Kamae, Mei, and Xie et al.…”