文章基本信息

标题：Detectable anthropogenic changes in daily-scale circulations driving summer rainfall shifts over eastern China
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作者：Baiquan Zhou ; Panmao Zhai ; Simon F B Tett 等
期刊名称：Environmental Research Letters
印刷版ISSN：1748-9326
电子版ISSN：1748-9326
出版年度：2021
卷号：16
期号：7
页码：74044
DOI：10.1088/1748-9326/ac0f28
出版社：IOP Publishing Ltd
摘要：Wetting in the south while drying in the north during the last few decades constitutes the well-known ‘southern flood–northern drought’ (SFND) precipitation pattern over eastern China. The fingerprint of anthropogenic influence on this dipole pattern of regional precipitation trends has not been confirmed, especially for forced changes in relevant dynamics at the synoptic scale. Using a process-based approach involving model experiments both with and without anthropogenic inputs, it is demonstrated that the occurrences of daily circulation patterns (CPs) governing precipitation over eastern China during 1961–2013 have been altered by human influence. Due to anthropogenic forcing, CPs favoring SFND have become more likely to occur at the expense of CPs unfavorable to SFND. Regression analysis shows that changes recorded in the occurrence of CPs from the factual simulations could explain a large part of the precipitation trends over eastern China. CP frequencies driven by purely natural forcing do not reproduce this dipole pattern nor the inferred magnitude of precipitation trends over eastern China. These results suggest that human influence has played a critical role in shaping the contrasting north–south precipitation trends.
关键词：circulation pattern; southern flood–northern drought; anthropogenic influence; dynamic and thermodynamic contribution