Oceanic and Atmospheric Processes in the Formation and Maintenance of the Cosmonaut Sea Deep-Water Polynya and their Relationship to Antarctic Climate

本项目将应用一个代表大气、海洋和海冰过程的高分辨率综合数值模式来维持南极沿海冰湖。冰湖是冬季海冰覆盖范围内开阔水域或冰浓度减少的大片反复出现的区域。这个项目的研究地点位于南极洲东部的宇航员海，面对印度洋。据推测，这个冰湖主要是由来自海洋的热量上涌维持的，而不是通过平流去除冰，它是由大气预处理、深海对流和局部地形相互作用调制的合流形成的。经常发生的融冰现象在南极气候系统中具有重要意义，因为它影响大气和海洋之间的表面热、水分和动量的交换，并影响海洋和海冰的化学和生物组成。该项目结合了高分辨率建模和遥感图像分析、台站观测和实验数据，以确定该冰湖形成的机制。多冰湖的尺度要求使用高分辨率的有限区域模式，因为全球气候系统模式既没有精确模拟多冰湖过程中许多重要过程和反馈所必需的分辨率，也没有复杂的参数化。该研究可作为其他南极深水融冰的概念模型，如威德尔海融冰。＊＊＊

*** 9725320 Lynch This project will apply a high resolution integrated numerical model that represents atmospheric, oceanic and sea ice processes to the maintenance of an antarctic coastal polynya. Polynyas are large recurrent areas of open water or reduced ice concentration within the winter sea ice cover. This project's study site is in the Cosmonaut Sea off East Antarctica, facing the Indian Ocean. It is conjectured that this polynya is maintained primarily by the upwelling of heat from the oceans rather than removal of ice by advection, and is formed as the result of a confluence of atmospheric preconditioning, deep ocean convection, modulated by local topographic interactions. Regularly occurring polynyas have importance in the antarctic climate system by influencing the surface exchange of heat, moisture, and momentum between the atmosphere and ocean, as well as affecting the chemical and biological composition of the ocean and sea ice. This project uses a combination of high resolution modeling and analysis of remotely sensed imagery, station observations, and experimental data to determine the mechanisms responsible for the formation of this polynya. The scale of the polynya requires the use of a high resolution limited area model, since global climate system models have neither the resolution nor the sophisticated parameterizations necessary to accurately model many of the important processes and feedbacks involved in polynya processes. This study can serve as a conceptual model for other antarctic deep water polynyas, such as the Weddell Sea polynya. ***