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

该项目将提供关于水蒸气和冰云在对流层上层温度极低时的红外吸收特性的新信息。方法是在南极站使用地面设备进行实验测量，那里的温度和水蒸气数量接近于中纬度高大气中的温度和水汽量。在自然大气中工作，而不是在受限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。这些实验中的主要仪器是覆盖2到40微米波长范围的高分辨率干涉仪。红外线辐射将在往返1公里的距离上传输出去，干涉仪将能够估计沿途的吸收。测量空气温度、水蒸气含量以及冰晶类型和浓度的仪器将为干涉仪测量提供数据支持。这项工作的结果将是更好地了解冰晶和水蒸气在极低温度下的辐射特性。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和(3)近似的精度。

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.