Enhanced Simulation of Atmospheric Blocking in a High‐Resolution Earth System Model: Projected Changes and Implications for Extreme Weather Events

作者：Yang Gao, Xiaojie Guo, Jian Lu, Tim Woollings, Deliang Chen, Xiuwen Guo, Wenbin Kou, Shaoqing Zhang, L. Ruby Leung, R. Schiemann, Christopher O’Reilly, Chuncheng Guo, Jianping Li, Huiwang Gao, Lixin Wu · 发表于：Journal of Geophysical Research Atmospheres · 年份：2025 · DOI：10.1029/2024jd042045 · 被引用次数：9 · 研究领域：Climate variability and models、Meteorological Phenomena and Simulations、Atmospheric and Environmental Gas Dynamics

Abstract Atmospheric blocking is closely linked to the occurrence of extreme weather events. However, low‐resolution Earth system models often underestimate the frequency of blocking, undermining confidence in future projections. In this study, we use the high‐resolution Community Earth System Model (CESM‐HR; 25 km atm and 10 km ocean) to show that CESM‐HR reduces biases in atmospheric blocking for both winter and summer, particularly for events lasting longer than 10 days. This improvement is partly due to reduced sea surface temperature biases at higher resolution. Additionally, applying a bias correction to the 500 hPa geopotential height further enhances blocking frequency simulations, highlighting the crucial role of the mean state. Under the Representative Concentration Pathway 8.5 scenario, CESM‐HR projects a decrease in wintertime blocking over regions such as the Euro‐Atlantic and Chukchi‐Alaska, consistent with previous studies. In contrast, summer blocking is expected to become more frequent and persistent, driven by weakened zonal winds. The blocking center shifts from historical locations over Scandinavia and eastern Russia to central Eurasia, significantly increasing blocking over the Ural region. Summer blocking frequency over the Scandinavia‐Ural region may eventually surpass historical winter blocking over the Euro‐Atlantic. This increase in summer blocking could exacerbate summer heatwaves in a warming climate, making severe heatwaves, like those observed re...