A33E-3230:
The Super Arctic Storm in 2012 - Investigation of Dynamics Mechanism
Wednesday, 17 December 2014
Wei Tao1, Jing Zhang1, Yunfei Fu2 and Xiangdong Zhang3, (1)North Carolina A & T State University, Greensboro, NC, United States, (2)USTC University of Science and Technology of China, Earth and Space, Hefei, China, (3)University of Alaska Fairbanks, Fairbanks, AK, United States
Abstract:
A strikingly super and long-lasting Arctic storm occurred in August 2012, along with which a record low sea ice extent was observed. In this study, the physical processes and mechanisms responsible for its long persistence and strong intensity were investigated by using the Weather Research and Forecast (WRF) model. The storm was generated over northeastern Siberian coast on August 2, 2012, and then moved into Arctic Ocean. It intensified to reach its minimum sea level pressure of 959hPa on August 6. Afterwards, the storm lingered over the Arctic Ocean for 7 days. Its intensity and duration is greater than 99% of all Arctic storms. Our WRF simulation results suggest that both troposphere baroclinic instability and Tropopause Potential Vorticity (TPV) anomaly contribute to the drastic intensification and long persistence of the storm. If only baroclinic instability is present, the storm can intensify to some degree of its observed strength but has very short lifetime. Without the troposphere baroclinic instability, TPV anomaly alone can help to maintain the storm persistence but the intensity is much weaker.
