Study on the Positive Temperature Anomalies in East Antarctica During the Winter of 2018

Abstract East Antarctica has experienced significant positive temperature anomalies during winter 2018, with Zhongshan (ZS) station recording its highest winter average temperature since 2008 and fourth highest since its establishment in 1989. This study employs observational data and ERA5 reanalysis to diagnose the phenomenon, revealing that temperature anomalies at 300 hPa are mainly driven by advection and adiabatic processes, which is the second highest recorded from 2000 to 2020. However, diabatic process are significantly important at 700 hPa, being the third highest during the period. The reduction in sea ice, combined with enhanced sinking motion and increased sea‐air temperature difference, together contributes to the variations of diabatic heating. The increased precipitation, exceeding the historical average by 100% along the southwestern shore of Prydz Bay, further induces localized warming. The increased atmospheric pressure associated with the negative Southern Annular Mode phase is the primary cause influencing the advection, adiabatic, and diabatic processes.