Antarctic Cloud Properties and Their Effect on the Surface Energy Budget

这项拟议的工作是研究如何利用卫星数据来提高我们对南极云特征如何影响辐射交换和南极冰盖表面能量收支的理解。目前的大气环流模式（GCMs）在考虑极地纬度云的影响方面是出了名的差，而且不能重现有效的地表温度和风。其原因在于冰表面和云顶在可见光谱中看起来非常相似，而表面温度和云顶温度的差异不足以在红外光谱中产生可识别的差异。如果不仔细考虑这些混杂效应，代表影响南极冰盖物质平衡的南极气候过程的模式的真实性就非常有限。本研究将涉及三个任务：(1)构建云量、高度、温度、相位（冰与水）、光学深度和有效粒子半径的气候学；(2)开展云、大气和地表特性对地表能量收支的敏感性研究；(3)结合卫星数据、GCM分析和区域气候模式生成改进的地表能量收支。尽管某些分量的不确定性可能很大，但这种高度的数据同化和整合所产生的能量收支预计将比目前在大尺度上可用的任何其他方法都更准确。

This proposed work is a study of how satellite data can be used to improve our understanding of how antarctic cloud characteristics affect the exchange of radiation and the surface energy budget of the antarctic ice sheet. Current general circulation models (GCMs) of the atmosphere are notoriously poor at incorporating the effects of clouds in polar latitudes, and cannot reproduce valid surface temperatures and winds. The reason for this lies in the fact that the ice surface and cloud tops look very much the same in the visible spectrum, and the surface temperatures and cloud top temperatures are not sufficiently different to produce identifiable differences in the infra-red spectrum. Without careful consideration of these confounding effects, models that represent antarctic climate processes affecting the mass balance of the antarctic ice sheet have a very limited verisimilitude.This study will be concerned with three tasks: (1) construct a climatology of cloud amount, height, temperature, phase (ice vs. water), optical depth, and effective particle radius; (2) conduct sensitivity studies of cloud, atmospheric, and surface properties on the surface energy budget, and (3) generate an improved surface energy budget by combining satellite data, GCM analyses, and a regional climate model.Even though the uncertainties in some components may be large, the energy budget resulting from this high degree of data assimilation and integration is expected to be more accurate than anything else currently available on the large scale.