Global assessment of AMSR-E and MODIS cloud liquid water path retrievals in warm oceanic clouds
Global assessment of AMSR-E and MODIS cloud liquid water path retrievals in warm oceanic clouds
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DOI：
10.1029/2009jd012662
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发表时间：
2009-11
影响因子：
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通讯作者：
C. Seethala;Á. Horváth
中科院分区：
文献类型：
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作者：
C. Seethala;Á. Horváth
在全局平均意义上，通过绝热校正消除了；然而，巨大的区域差异仍然存在。最值得注意的是，MODIS 在高纬度地区表现出严重高估，我们将其追溯到低太阳异质云上平面平行可见近红外反演中的 3D 效应。在热带或亚热带地区，AMSR-E-MODIS差异还取决于云类型，MODIS在层状云中高估而在积状云中低估，导致大范围的相干偏差模式，其中海洋Sc转变为信风Cu。我们注意到温茨云温度误差和 MODIS 1.6-3.7 mm 水滴有效半径差异具有类似的地理变化，这表明由于云吸收不确定性引起的微波反演误差和由于云垂直分层引起的可见近红外反演误差可能导致了观测到的液态水路径偏差模式。最后，发现云雨划分在 180 g m -2 以上的温茨反演中引入了系统性低偏差，因为微波算法错误地将较厚的非降水云中液态水含量的增加部分分配给了雨。
removed, in a global mean sense, by adiabatic correction; however, large regional differences remained. Most notably, MODIS showed strong overestimations at high latitudes, which we traced to 3‐D effects in plane‐parallel visible‐near‐infrared retrievals over heterogeneous clouds at low Sun. In the tropics or subtropics, AMSR‐E‐MODIS differences also depended on cloud type, with MODIS overestimating in stratiform clouds and underestimating in cumuliform clouds, resulting in large‐scale coherent bias patterns where marine Sc transitioned into trade wind Cu. We noted similar geographic variations in Wentz cloud temperature errors and MODIS 1.6–3.7 mm droplet effective radius differences, suggesting that microwave retrieval errors due to cloud absorption uncertainties, and visible near‐infrared retrieval errors due to cloud vertical stratification might have contributed to the observed liquid water path bias patterns. Finally, cloud‐rain partitioning was found to introduce a systematic low bias in Wentz retrievals above 180 g m −2 as the microwave algorithm erroneously assigned an increasing portion of the liquid water content of thicker nonprecipitating clouds to rain.