A clear-sky radiance archive from Meteosat "water vapor" observations.
A clear-sky radiance archive from Meteosat "water vapor" observations.
复制标题
来自气象卫星“水蒸气”观测的晴空辐射档案。
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
L. Picon
中科院分区：
文献类型：
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作者：
H. Brogniez;R. Roca;L. Picon
本文介绍了1983年7月至1997年2月晴空气象卫星“水汽”观测的长期档案，时间步长为3小时，空间分辨率为0.625°。云的清除使用基于国际卫星云气候学项目DX产品的场景选择程序进行。在这个过程中，由于低层大气在这个光谱波段的贡献可以忽略不计，低云场景被保留了下来。云污染对晴空辐射（CSR）场的影响较小，主要局限于小于0.5 K的大陆热带辐合带。这种场景选择产生了一个显著增强的采样相对于纯净的晴空在副高地区。根据现有技术对14年数据库进行均匀化。与操作无线电探空仪档案的比较表明，在整个周期内，0.3 K的小偏差是稳定的。对CSR变率的初步分析表明，亚热带干旱地区的季节内变化在北半球具有强烈的季节周期，而南半球没有观察到这种周期。这样的数据集完善了目前可用于记录对流层从气候到区域和日尺度的水汽变化的数据集。
A long-term archive of clear-sky Meteosat “water vapor” observations, covering the July 1983 to February 1997 period with a 3 hourly time step and a spatial resolution of 0.625°, is presented. Cloud clearing is performed using a scene selection procedure based on the International Satellite Cloud Climatology Project DX product. In this procedure low cloud scenes are kept because of the negligible contribution of the low atmospheric layer in this spectral band. Cloud contamination is shown to have little influence on the clear-sky radiance (CSR) field and is mainly confined to the continental Intertropical Convergence Zone with values less than 0.5 K. This scene selection yields to a significantly enhanced sampling with respect to pure clear-sky in the subtropical high regions. Homogenization of the 14 year database is performed in accordance with existing technique. A comparison to the operational radiosondes archive indicates a small bias of 0.3 K that is stable throughout the period. A first analysis of the CSR variability reveals that the intraseasonal variance over the subtropical dry regions has a strong seasonal cycle in the Northern Hemisphere that is not observed in the Southern Hemisphere. Such a data set completes the ones currently available to document the water vapor variability of the troposphere from climatic down to regional and daily scales.