交叉定标产生的NOAA卫星长期大气温度观测资料

介绍一套用于气候变化研究的NOAA卫星微波观测资料, 资料为全球5 d平均, 2.5°×2.5°经纬网格, 3个深层大气(对流中层、对流层顶以及平流层下层)的温度分布。该文简介了资料产生的方法, 包括交叉定标、角度订正、网格化以及网格误差修正等, 给出了使用这套资料分析得到的1987—2006年间不同大气层的温度变化趋势, 并提供了获取这套资料的方法。

A Long-term Atmospheric Temperature Dataset Derived from NOAA Microwave Sounding Unit with Cross-calibration

The Microwave Sounding Unit(MSU)on board the National Oceanic and Atmospheric Administration(NOAA)polar-orbiting satellites measures the atmospheric temperature from the surface to the lower stratosphere under all weather conditions, excluding precipitation. These instruments are extensively used to determine the atmospheric temperature trend. However, calibration errors are a major source of uncertainties in the trend determination. Recently, NOAA/National Environmental Satellite, Data and Information Services has developed a non-linear sequential calibration method using simultaneous nadir overpass(SNO)to reduce calibration errors and then a long term MSU deep layer atmospheric temperature dataset is generated based on the new calibration. The dataset is introduced, which includes global 5-day averaged deep-layer temperatures for the mid-troposphere, tropopause, and lower-stratosphere with grid resolution of 2.5° latitude by 2.5° longitude. Also, the methodologies for the dataset generation are described, which including cross-calibration, incident angle correction, grid data generation, and bias correction in gridded data. The 20-year climate trends during 1987—2006 for the three layers are obtained from the dataset. Finally, the website for acquiring the dataset is provided.