Decadal Variations in the Summer Precipitation Over Eastern China Associated With Spring Arctic Sea Ice.

This study investigated the contribution of Arctic sea ice concentration (SIC) on decadal variations of the dominant mode of summer precipitation over eastern China during 1981–2020. The spatial pattern of leading empirical orthogonal function mode has changed from a dipole pattern with negative anomalies over Jianghuai Valley and positive anomalies over southern China during 1981–2001 to the Yangtze River Valley (YRV) pattern during 2002–2020. Spring SIC over Kara Sea was significantly related to the dipole pattern, through influencing Eurasian snow depth. The associated anomalous temperature gradient and atmospheric circulation affected the meridional displacement of the East Asian subtropical jet, which favored the dipole pattern of summer precipitation. For the YRV pattern, spring SIC over Greenland Sea has an impact on the sea surface temperature anomalies in the western Pacific by triggering a wave train that influenced the precipitation through the establishment of the Pacific–Japan pattern. The results of this study may provide reference value for the prediction of summer precipitation over eastern China. Plain Language Summary: As Eastern China has a high level of national economic development and experiences significant variations in summer precipitation, it is crucial to comprehend the patterns and trends of rainfall. However, it is challenging to accurately predict the decadal variations of precipitation due to the intricate physical processes involved. Therefore, we consider exploring the causes of the decadal variations from the perspective of Arctic SIC. The study demonstrates the dominant mode of eastern China summer precipitation (ECSP) undergone a decadal variation at the early 2000s, and spring SIC over Kara Sea and Greenland Sea play great impacts on it. These results may have potential implications for ECSP forecasting. Key Points: Dominant mode of the summer precipitation over eastern China (ECSP) experienced a decadal variation at the early 2000sSpring sea ice concentration (SIC) over Kara Sea contributed to the dipole pattern of ECSP by influencing the Eurasian snow depth during 1981–2001Spring SIC over Greenland Sea impacted the Yangtze River Valley pattern through the western Pacific sea surface temperature during 2002–2020 [ABSTRACT FROM AUTHOR]