Work

Influence of the Polar‐Eurasia Pattern on Interannual Variations in Extratropical Transition of Western North Pacific Tropical Cyclones

Year: 2026

Type: article

Abstract: This study investigates climate drivers influencing interannual changes in the extratropical transition (ET) of western North Pacific tropical cyclones (TCs) during July–October from 1979 to 2024. We find a pronounced relationship between the fraction of TCs experiencing ET (ETTCs) to all TCs and the Polar‐Eurasia (POL) pattern. There is a significantly lower ETTC fraction in positive POL years relative to negative POL years. This lower ETTC fraction can be linked to significant decreases in the 700‐hPa maximum Eady growth rate spanning 30°–40°N. Poleward‐moving TCs have to travel for a longer distance to reach the region favorable for baroclinic development, reducing their ET probability. There are only slight changes in maximum potential intensity over the basin. The POL‐induced changes in atmospheric conditions are further explained by strong (weak) southward propagation of wave energy originating from the polar regions at middle (lower) levels.

Source: Geophysical Research Letters

DOI: 10.1029/2026gl122808

Authors: Nannan Qin, Rongqiang Qu, Jinjie Song, Philip J. Klotzbach, Yihong Duan

Institutions: Jiangsu Provincial Meteorological Bureau, Chinese Academy of Meteorological Sciences, Colorado State University, Chinese Academy of Sciences, State Key Laboratory of Severe Weather

Language: English

Topic: Tropical and Extratropical Cyclones Research

Subfield: Atmospheric Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDG: Climate action

Open Access status: gold

Estimated APC paid: $3,190