Decadal Variation in the Impact of the NAO and Ural Blocking on Subseasonal Variation of the East Asian Winter Monsoon

Extreme cold events have become more frequent in recent years, including persistent freezing rain events in Southern China in early 2008 and a severe cold surge in Hong Kong in January 2016. In order to improve the predictability of extreme cold events and better understand the subseasonal variation of the East Asian winter monsoon (EAWM) and large-scale atmospheric circulation, this investigation will advance our understanding of the physical mechanisms controlling subseasonal variability of cold surges in South China and its relationship with various climate drivers such as Atlantic multi-decadal variability (AMV) and Pacific multi-decadal variability (PMV). We aim to investigate the dominant subseasonal variations of the EAWM and the underlying mechanisms, to examine the atmospheric response to AMV and PMV in climate models, and to understand the impact of the North Atlantic Oscillation (NAO) on Ural blocking and the EAWM using a new conceptual model and dynamical framework. The outcomes of this study are expected to help address the following questions:● How much do we not understand about the mechanisms responsible for subseasonal variability of the EAWM under different decadal backgrounds?● What kinds of extreme cold events are we more vulnerable to and how can they be predicted on subseasonal timescales?The answers to these questions are important for informing and guiding decision making, especially for policy reform, loss minimization and mitigation, and resilience strategies.