Estimation of liquid water content and water vapor amount in the polar region

云和水汽是影响南极气候的重要因素。本研究的目的是获得利用地面微波观测和卫星资料反演云液态水含量和水汽含量的方法.至于微波观测，检查了12、19和37千兆赫三个频率范围的辐射计。从日本的初步观测来看，三个频段的辐射计组合对云信息的获取是有效的。然而，在极地地区，由于少量的液态水和水蒸气，12 GHz的辐射计是不合适的，19 GHz的辐射计，这是预期是有效的水汽测量，没有提供一个有意义的水蒸气值。结果表明，在水汽和液态水含量较少的极地大气中，如果对天线的物理温度进行监测，37 GHz辐射计的单频测量就足以推算出液态水含量.对利用NOAA卫星AVHRR资料判别云的方法进行了研究。由于在极地地区的积雪表面的云层覆盖是很难单独通过可见光反射或红外亮度温度检测，红外亮度温度的差异被用来。将4 μ m区域（ch 3）和10 μ m区域（ch 4）、10 μ m和12 μ m区域（ch 5）中的亮度温度之间的差异与亮度温度和差异的二维直方图一起使用.利用NOAA卫星的TIROS业务垂直探测器（TOVS）反演大气水汽总量。由于强地表反演影响分析，采用了显式考虑地表温度的迭代方法。与高空气象资料相比，虽然垂直廓线显示出很大的差异，但水汽柱量在很小的变化范围内一致。

Clouds and water vapor work as an important factors of the climate in the Antarctic. This study aimes to obtain the method to derive liquid water content of clouds and water vapor amounts from groundbased microwave observations and satellite data.1. As for the microwave observation, radiometers of three frequency range, 12, 19 and 37 GHz were examined. From the preliminary observation in Japan, combination of rediometers of three frequency regions works effective to get the cloud information. However, in the polar region, because of small amount of liquid water and water vapor, 12 GHz radiometer was not suitable and 19 GHz radiometer, which was expected to be effective for water vapor measurements, did not offer a meaning value of water vapor. It was shown that the single frequency measurements by the 37 GHz radiometer was enough to derive liquid water content under the polar atmosphere where the amount of water vapor and liquid water are small, if the physical temperature of antenna was monitored.2. The method to discriminate clouds by AVHRR data of NOAA satellite was examined. Since the cloud cover over the snow surface in the polar region is difficult to detect only by the visible reflection or infrared brightness temperature, the differences of infrared brightness temperatures were used. The differences between the brightness temperature in 4 mum region (ch 3) and 10 mum region (ch 4), 10 mum and 12 mum region (ch 5) were used together with the 2 dimentional histogram of the brightness temperature and the difference.3. Atmospheric water vapor amount was derived from the TIROS Operational Veritcal Sounder (TOVS) of NOAA satellite. Since the strong surface inversion affects the analysis, iteration method with considering the surface temperature explicitly was used. Comparing to the aerological data, though the vertical profile shows large disagreements, the column amounts of water vapor agreed within small variations.