Simulation of Northern Winter Stratospheric Polar Vortex Regimes in CESM2-WACCM

The possible impact of various Arctic polar vortex regimes for the stratosphere on Northern Hemisphere extratropics has not been fully understood. Previous study classified stratospheric to six using k-mean clustering algorithm based ERA5 reanalysis. stability and robustness classification is further verified with a much longer model dataset historical integrations from CESM2-WACCM. Consistent reanalysis, we clustered forms into patterns, named as homogeneously-intensified -weakened (HI, HW), North America-intensified (NAI, HAW), Eurasia-intensified (EUI, EUW). A zonally uniform positive (negative) Annular Mode (NAM) pattern develops during HI (HW) regime troposphere. NAM-like shifts toward western hemisphere largest negative (positive) anomalous height center shifting America NAI (NAW) regime. In contrast, maximum anomaly moves towards Eurasia EUI (EUW) HI, NAI, EUW are accompanied weakened wave activities, while HW, NAW, preceded by enhanced planetary waves. Accordingly, persistent anomalies warmth (coldness) exist over midlatitude (HW). Anomalous centers in northern Eurasia, coldness (warmth) around Mediterranean Sea develop East Asia periods. rainfall distributions also vary frequency SSWs strong events assessed consistent previous findings.