Driving Roles of Tropospheric and Stratospheric Thermal Anomalies in Intensification and Persistence of the Arctic Superstorm in 2012. Issue 19 (5th October 2017)

• Record Type: Journal Article
• Authors: Tao, Wei; Zhang, Jing; Fu, Yunfei; Zhang, Xiangdong
• Is Part Of: Geophysical research letters. Volume 44:Issue 19(2017)
• Page Start: 10, 017
• Page End: 10, 025
• Publication Date: 2017-10-05
• Subjects: Arctic storm -- thermal anomalies -- intensification -- persistence; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL074778
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Intense synoptic‐scale storms have been more frequently observed over the Arctic during recent years. Specifically, a superstorm hit the Arctic Ocean in August 2012 and preceded a new record low Arctic sea ice extent. In this study, the major physical processes responsible for the storm's intensification and persistence are explored through a series of numerical modeling experiments with the Weather Research and Forecasting model. It is found that thermal anomalies in troposphere as well as lower stratosphere jointly lead to the development of this superstorm. Thermal contrast between the unusually warm Siberia and the relatively cold Arctic Ocean results in strong troposphere baroclinicity and upper level jet, which contribute to the storm intensification initially. On the other hand, Tropopause Polar Vortex (TPV) associated with the thermal anomaly in lower stratosphere further intensifies the upper level jet and accordingly contributes to a drastic intensification of the storm. Stacking with the enhanced surface low, TPV intensifies further, which sustains the storm to linger over the Arctic Ocean for an extended period. Key Points: An intense and persistent storm hit the Arctic in August 2012 associated with pronounced thermal anomalies from surface to lower stratosphere Baroclinity associated with tropospheric thermal anomalies drives the initial intensification of the storm Coupling between the storm center and tropopause vortex associated upper level thermal anomalies further intensifies and sustains the storm