TRMM Precipitation Radar and Microwave Imager Observations of Convective and Stratiform Rain Over Land and Their Theoretical Implications
TRMM Precipitation Radar and Microwave Imager Observations of Convective and Stratiform Rain Over Land and Their Theoretical Implications
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DOI：
10.2151/jmsj.80.1183
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发表时间：
2013-08
期刊：
影响因子：
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通讯作者：
C. Prabhakara;R. Iacovazzi;Jung-Moon Yoo
中科院分区：
文献类型：
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作者：
C. Prabhakara;R. Iacovazzi;Jung-Moon Yoo
利用热带降雨测量使命任务（TRMM）微波成像仪（TMI）辐射计对陆地亮温Tb的观测，结合TRMM卫星上降水雷达（PR）对反射率因子Z的垂直廓线的几乎同时测量，分析了TMI辐射计对陆地亮温Tb的观测结果。此外，这种分析是分别在对流和层状雨区。该检查揭示了TMI和PR数据之间的明确关系。这种关系的可能的解释是探索与辐射传输计算的帮助下。用这种方法，我们证明了85 GHz的TMI观测可以粗略地模拟Z。然而，37和19千兆赫的观测没有得到很好的模拟，这可能是因为在这些通道的广泛足迹中水凝物分布的水平不均匀性和陆地表面发射率引起的污染。另一方面，从TMI和PR观测，我们发现，亮度温度差（T19-T37）最大限度地减少了这些误差源。我们对对流雨区（T19-T37）的模拟与这一发现是相当一致的。这项调查表明，TMI 85 GHz信道产生的最佳信息的降雨在热带地区的土地，因为它具有最小的表面污染，强大的消光，和一个良好的足迹。亮温差（T19-T37）可以补充85 GHz通道给出的信息。
Observations of brightness temperature, Tb, made over land regions by the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) radiometer are analyzed with the help of nearly simultaneous measurements of the vertical profiles of reflectivity factor, Z, made by the Precipitation Radar (PR) onboard the TRMM satellite. Furthermore, this analysis is done separately over convective and stratiform rain regions. This examination reveals a clear relationship between TMI and PR data. Possible explanation for this relationship is explored with the help of radiative transfer calculations. With this approach, we demonstrate that the 85 GHz observations of TMI can be simulated crudely from the observations of Z. However, the 37 and 19 GHz observations are not as well simulated, possibly because of horizontal non-uniformity in the hydrometeor distribution in the broad footprints of these channels and contamination introduced by land-surface emissivity. On the other hand, from TMI and PR observations, we find that the brightness temperature difference (T19-T37) minimizes these sources of error. Our simulations of (T19-T37) over convective rain regions are in reasonable agreement with this finding. This investigation indicates that the TMI 85 GHz channel yields the best information about rain over tropical land, because it has minimal surface contamination, strong extinction, and a fine footprint. The brightness temperature difference (T19-T37) can supplement the information given by the 85 GHz channel.