Mesoscale Modeling of the Atmosphere over Antarctic Sea Ice: A Late-Autumn Case Study

Author:

Valkonen Teresa1,Vihma Timo2,Doble Martin3

Affiliation:

1. Department of Physics, University of Helsinki, Helsinki, Finland

2. Finnish Meteorological Institute, Helsinki, Finland

3. Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, United Kingdom

Abstract

Abstract Atmospheric flow over Antarctic sea ice was simulated applying a polar version of the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (Polar MM5). The simulation period in late autumn lasted for 48 h, starting as northerly warm airflow over the Weddell Sea ice cover and turning to a southwesterly cold-air outbreak. The model results were validated against atmospheric pressure and wind and air temperature observations made by five buoys drifting with the sea ice. Four different satellite-derived sea ice concentration datasets were applied to provide lower boundary conditions for Polar MM5. During the period of the cold-air outbreak, the modeled air temperatures were highly sensitive to the sea ice concentration: the largest differences in the modeled 2-m air temperature reached 13°C. The experiments applying sea ice concentration data based on the bootstrap and Arctic Radiation and Turbulence Interaction Study (ARTIST) algorithms yielded the best agreement with observations. The cumulative fetch over open water correlated with the bias of the modeled air temperature. The sea ice concentration data affected the simulated air temperature in the lower atmospheric boundary layer, but above it the temperature and wind fields were more strongly controlled by the boundary layer scheme applied in Polar MM5. Analysis nudging applying four-dimensional data assimilation had a positive effect on the pressure and wind fields but negative or no effect on the air temperature fields. The results suggest that applying a sea ice model to update sea ice fields frequently throughout atmospheric model simulations will likely lead to important improvements in forecasts.

Publisher

American Meteorological Society

Subject

Atmospheric Science

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3