青藏高原雨季降水凝结潜热的估算研究

Estimation of Precipitation Latent Heat in Rainy-Season over Qinghai-Xizang Plateau

利用美国NOAA系列卫星观测的青藏高原区（75°～105°E，25°～40°N）水平分辨率为2．5°×2．5°经纬度网格，共91个网格点的1974年6月-2005年12月的月平均射出长波辐射（简称OLR）资料，青藏高原93个常规气象站的1961-2005年的月降水资料，在研究降水量与OLR关系及其气候分区的基础上，分区、分网格建立了利用OLR估算降水量，进而估算降水凝结潜热的数学模型。利用所得模型计算出青藏高原雨季1961-2005年历年逐月的降水凝结潜热。结果表明，高原东部多年平均降水量为401．5mm，凝结潜热为18．55×10^20J。近45年高原东部的降水凝结潜热有所增大，其递增率为0．218×10^20J／10a，相当于每10年增加1.2％。高原总体的降水凝结潜热及其变率略大于高原东部。

The data of this paper includes two parts, one is the monthly average data of Outgoing Long-wave Radiation （OLR） from June 1974 to December 2005, which is observed by the National Oceanic and Atmospheric Administration （NOAA） satellites, there are altogether ninety-one grid points in the regions of 75°-105°E and 25°-40°N and the horizontal resolution ratio is 2. 5°×2. 5° Lon./Lat.. Another is the monthly rainfall data of ninety-three conventional meteorological station of the Qinghai-Xizang Plateau during the period of 1961-2005. On the basis of the relationship between rainfall and OLR and the partition of climatic zone, the mathematic model is established in each zone and grid, which is used for estimating the monthly rainfall, and then estimating the monthly precipitation latent heat year by year from 1961 to 2005. It shows that the annual average rainfall is 401.5 mm and the latent heat is 18.55 × 10^20J in the eastern part of the Qinghai-Xizang Plateau, which has some increase in recent 45 years, and the increasing rate is 0. 218 × 10^20J/10a, that is to say, it will increase 1.2 percent in each decade. Furthermore, the total latent heat and its variability of the Qinghai-Xizang Plateau have a little greater than the eastern part.