Collaborative Research: Longwave Radiation Processes on the Antarctic Plateau

* 9807501瓦尔登 本项目是南极站近地面长波辐射过程的实验研究。 能够高分辨率测量雪表面红外辐射通量的仪器--所谓的傅里叶变换干涉仪--将于1999年底开发并安装到位，并在接下来的南半球冬季运行。 将对低层大气的温度和湿度分布以及大气边界层的冰晶进行辅助观测。 长波辐射（也称为红外辐射或热辐射）是大气能量平衡的重要组成部分。在南极大陆，辐射过程主导着表面能量收支。 在夏季，平衡由四项组成（入射和反射的短波或太阳辐射，以及发射和反射的长波辐射）;在冬季日落后，短波项为零。 发射的长波辐射随温度而变化，因此表面的辐射平衡条件将决定表面温度的特定值。 这项研究包括几个关于雪的排放特性的实验，在大气中的冰晶，和近地表的温室气体。 云底高度、温度和湿度结构、冰晶大小和浓度等并发环境条件将允许发展云特性的气候学，并大大改进大气环流模式中辐射过程的表示。 ***

*** 9807501 Walden This project is an experimental study of long-wave radiation processes near the surface at South Pole station. Instrumentation capable of high resolution measurements of the infrared radiation fluxes at the snow surface -- a so-called Fourier Transform Interferometer -- will be developed and put in place in late 1999 and operated through the following austral winter. Supporting observations of the temperature and moisture profiles in the lower atmosphere, and of ice crystals in the atmospheric boundary layer will be made. Long-wave radiation (also called infrared or thermal radiation) is an important component in the energy balance of the atmosphere. On the antarctic continent radiation processes dominate the surface energy budget. In summer the balance is made up of four terms (incoming and reflected short-wave or solar radiation, and emitted and reflected long-wave radiation); in winter after sunset the short-wave terms are zero. The emitted long-wave radiation varies with temperature so that the condition of radiation balance at the surface will determine a particular value of the surface temperature. This study includes several experiments concerning the emission characteristics of snow, of ice crystals in the atmosphere, and of greenhouse gases near the surface. The concurrent environmental conditions such as cloud base altitude, temperature and humidity structure, ice crystal sizes and concentrations will allow the development of a climatology of cloud properties, and substantially improved representations of radiation processes in general circulation models. ***