报告题目： Blowing-Snow Enhanced Surface-Air Interactions during Extreme Weather Events from the Arctic to Midlatitudes
The occurrence of extreme winter weather events has ostensibly increased in both the Arctic and midlatitudes. These events often bring snowfall and strong winds to the impacted area – resulting in blowing snow. Drifted snow can complicate the surface–air interactions and feedback to further strengthen the extreme event, particularly over some specific heterogeneous surfaces such as Arctic sea ice/polynya or a midlatitude urban/lake area. To better understand and compare the blowing snow effects on the surface-air interactions in the Arctic and midlatitudes, we apply a snow/ice-enhanced version of the Weather Research and Forecasting model to conduct simulations on two extreme weather events. The first event occurred in the Arctic during February 22-26, 2018, when extremely strong surface winds (>25 m/s) and an unprecedented polynya off the north coast of Greenland developed due to a synergistic effect of an intense cyclone centered to the north of the Canadian Arctic Archipelago and a strong anticyclone northeast/east of Iceland. The second event is a winter blizzard in the Great Lakes area during December 22-25, 2022. The blizzard brought strong winds (>20 m/s), a 40-year record cold temperatures, and snowfall to the area, resulting in white-out conditions by the blowing snow. The modeling results reveal significant thermodynamic effects of blowing snow sublimation, which can be further enhanced by the presence of an Arctic polynya or a midlatitude urban environment. Moreover, the blowing snow sublimation effect also contributes to a continuing development of the polynya in the Arctic and a stronger lake-effect snow in the Great Lakes area.
Jing Zhang is a professor of atmospheric sciences at Department of Physics, North Carolina A&T State University (NCAT). Her research interests lie in regional weather and climate studies by the means of numerical modeling and data analysis. Specifically, her recent and ongoing research studies include mesoscale modeling of downslope winds for wildfire study; urban modeling; glacier/ice-sheet surface mass balance modeling; Arctic cyclone modeling; regional reanalysis for the Arctic coast of Alaska; land/ice/snow surface processes and interactions with the atmosphere; and real-time weather forecast.