Enhanced Subseasonal Variability of Spring Temperature Over Eastern China in 2022: Initial Role of Extremely Heavy Arctic Sea Ice in Previous Winter

• Published in: Geophysical Research Letters
• Main Authors: Wenshu Xu, Shuangmei Ma, Congwen Zhu
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2023
• Subjects: Geophysics. Cosmic physics; QC801-809; Arctic; North Atlantic; Sea ice
• Online Access: https://doi.org/10.1029/2023GL106017; https://doaj.org/article/fa359ff3e0ab4c07b64f91ac7fbb8ff5

Abstract In spring 2022, strong temperature whiplash events occurred in eastern China (EC), characterized by enhanced subseasonal variability in surface air temperature (SAT). Our results show that extreme temperature fluctuations are dominated by the amplified Eurasian wave train on a biweekly timescale as a possible response to increased sea ice concentrations (SICs) over the Barents‐Kara Seas (BK) in previous winter. Increased winter SICs weaken the upward planetary waves and enhance the stratospheric polar vortex. In spring, the downward propagation of enhanced polar vortex intensifies the polar front jet, increasing kinetic energy gain of the North Atlantic wave train and guiding it to travel farther eastward. The Eurasian wave train strengthens through an upstream development and enhanced local baroclinicity and enhances subseasonal SAT variability over EC. Therefore, the state of BK SICs in previous winter could be a useful signal for the enhanced likelihood of spring extreme temperature whiplash events.