Collaborative Research: The Surface of the Antarctic Plateau as a Natural Laboratory for Radiation Processes in the Global Upper Troposphere: Water Vapor and Ice Clouds

该项目将提供关于对流层上部温度极低时水蒸气和冰云的红外吸收特性的新信息。方法是在南极站使用地面设备对这些量进行实验性测量，南极站的温度和蒸汽量与中纬度高大气层的温度和蒸汽量接近。 在自然大气中而不是在狭窄的实验室空间中工作，可以使用较长的实验路径长度，从而获得比其他方式更精确的数据。 在这些实验中的主要仪器是一个高分辨率的干涉仪，覆盖从2到40微米的波长范围。 红外辐射将在1公里的往返距离上传播出去和回来，干涉仪将能够估计沿着路径的吸收，测量空气温度、蒸汽含量、冰晶类型和浓度的仪器将提供支持干涉仪测量的数据。 这项工作的结果将是更好地了解冰晶和水蒸气在非常低的温度下的辐射特性。 需要这些信息来提高（1）辐射传输计算，（2）卫星对大气的遥感观测，以及（3）近似值的准确性。

This project will provide new information on the infrared absorbing properties of water vapor and ice clouds at the very low temperatures present in the upper troposphere. The approach is to measure these quantities experimentally using ground-based equipment at the South Pole Station, where temperatures and vapor amounts approximate those in the high atmosphere at midlatitudes. Working in the natural atmosphere rather than in a confined laboratory space, it is possible to use long experimental path lengths and thereby obtain more precise data than possible otherwise. The principal instrument in these experiments is a high-resolution interferometer covering the wavelength range from 2 to 40 micrometers. Infrared radiation will be transmitted out and back over a round-trip distance of 1 km and the interferometer will be able to estimate the absorption along the path. Instruments to measure the air temperature, vapor content, and type and concentration of ice crystals will provide data in support of the interferometer measurements. The result of the work will be a better understanding of the radiative properties of ice crystals and water vapor at very low temperatures. This information is needed to improve the accuracy of (1) radiative transfer calculations, (2) remote sensing observations of the atmosphere from satellites, and (3) the approximations.