Regional Variability in Summer Extreme Precipitation over Northern China and Associated Atmospheric Teleconnections from 1961 to 2022

This study presents a comprehensive analysis of summer extreme precipitation in northern China from 1961 to 2022, emphasizing regional characteristics, temporal trends, and underlying mechanisms. The results reveal distinct regional differences in extreme precipitation between western northern China (WNC) and eastern northern China (ENC). During recent decades, WNC has experienced a significant increase in both the amount and frequency of summer extreme precipitation, with rates of 1.77 mm and 0.19 days per decade, respectively, alongside a rising contribution of extreme precipitation to total summer precipitation. In contrast, no significant trends are observed in ENC. Further investigation into atmospheric circulation anomalies reveals that, on an interannual timescale, summer extreme precipitation in WNC is influenced by the joint effects of the British-Baikal Corridor (BBC) pattern and Silk Road Pattern (SRP), whereas that in ENC is modulated by the combined influence of the polar-Eurasian (POL) and North Atlantic Oscillation (NAO) patterns. Additionally, sea surface temperature (SST) anomalies indicate that two distinct SST patterns in the North Atlantic exert significant impacts on summer extreme precipitation in WNC and ENC, respectively. Specifically, the tripolar SST pattern associated with WNC summer extreme precipitation influences it primarily by triggering the BBC pattern, while the SST pattern linked to ENC summer extreme precipitation operates via generating the POL and NAO patterns which work synergistically. This study enhances our understanding of the regional variability of summer extreme precipitation in northern China and its associated atmospheric and oceanic drivers.