In order to study storm activities, the individual and collaborative impacts of stratosphere vortex and troposphere baroclinity in the development of Arctic storms were explored with the Weather Research and Forecasting (WRF) model. In a long-lasting Arctic storm in September 2010, it is found the downward intrusion of stratosphere vortex and the resultant upper level positive potential vorticity (PV) anomaly play decisive roles in the storm’s intensification and persistence over an extended period. In the super strong Arctic storm in August 2012, thermal anomalies in both the troposphere and stratosphere are necessary for the storm’s drastic development. The troposphere baroclinity along the Arctic Front Zone, as well as the enhanced upper level positive PV anomaly due to stratosphere warm anomalies contribute to a strong jet and accordingly accelerate the deepening rate of the surface low. In both cases, the out-of-phase occurrence in the maxima of the stratosphere warm and troposphere cold anomalies sustains the intensity of the PV anomalies around the tropopause, which in turn further supports the storm’s persistence.
JING ZHANG is Associate Professor of Atmospheric Sciences at the Department of Physics and Department of Energy and Environmental Systems at North Carolina A&T State University. Jing Zhang’s research interests lie in regional climate and weather studies by the means of numerical modeling and data analysis. Specifically, her recent and ongoing research studies include: mesoscale wind field study over complex topography in the Arctic marginal ice zone; data assimilation and its application for regional reanalysis; regional climate downscaling; modeling studies of Arctic storms; surface mass balance modeling for the Antarctic Peninsula. Through these activities, Zhang wishes to gain a better understanding of regional changes in the polar regions.