Synergistic effect of boreal autumn SST over the tropical and South Pacific and winter NAO on winter precipitation in the southern Europe

Abstract We find a positive phase of meridional tripole pattern of boreal autumn sea surface temperature anomalies over the tropical and South Pacific (TSPT+ ) has a synergistic effect with winter negative NAO (NAO−) on the amplitude and occurrence of winter precipitation in southern Europe (SEWP)....

Full description

Bibliographic Details
Published in:npj Climate and Atmospheric Science
Main Authors: Xinxin Tang, Jianping Li
Format: Article in Journal/Newspaper
Language:English
Published: Nature Portfolio 2024
Subjects:
Online Access:https://doi.org/10.1038/s41612-024-00628-y
https://doaj.org/article/0ded098a33674f7b8d8c97760f36c771
Description
Summary:Abstract We find a positive phase of meridional tripole pattern of boreal autumn sea surface temperature anomalies over the tropical and South Pacific (TSPT+ ) has a synergistic effect with winter negative NAO (NAO−) on the amplitude and occurrence of winter precipitation in southern Europe (SEWP). This synergistic effect is attributed to the linear superposition and nonlinear effect of winter NAO− and preceding autumn TSPT+ . The autumn TSPT+ can persist into winter, and the winter TSPT+ with NAO− can stimulate a greater amount of Rossby wave energy propagating to the North Atlantic-Europe (NAE) region than without NAO−, and thereby synergistically regulating circulation with winter NAO−. Thus, winter NAO− and autumn TSPT+ have a synergistic effect on the northwest-southeast trending positive-negative-positive winter circulation over the NAE region. Driven by the intensified mean circulation, water vapor transports and storm activity over southern Europe are evidently strong, which is in favor of SEWP formation.