Determination of Cloud Radiative Properties from Satellite Observations

卫星视场的处理 国际卫星云气候学项目（ISCCP）许可证 只有两个描述性类别：无污染或受污染 云。 对于云污染的情况，单层 “有效”云模型，然后用来推导辐射 云的性质，这是假定是空间 均匀的平面平行，具有固定的散射特性。 一个 区分破碎云和均匀云的能力， 计算辐射通量的深远影响， 大气层的表面和顶部。 空间相干性 方法”（Coakley和Bretherton，1982年）旨在解决 这一问题，通过利用“结构”之间的 像素来检索云覆盖百分比。 利用4公里AVHRR数据，Coakley博士将得出经验 太平洋云量和辐射特性的估计 南纬50度至50度的大西洋盆地 北 他将确定云的几何形状对其 反射率，并评估云在红外波长的不透明度 以及空间相干方法的可能偏差。 科克利医生 还将与ISCCP科学家合作， 对比两种不同方法的结果。

The treatment of satellite fields-of-view in the International Satellite Cloud Climatology Project (ISCCP) permits only two descriptive categories: either free of or contaminated by clouds. For the cloud-contaminated cases, a single-layer "effective" cloud model is then used to derive the radiative properties of the cloud, which is presumed to be spatially homogeneous plane-parallel with fixed scattering properties. An ability to distinguish either broken or uniform clouds has profound consequences for computing radiative fluxes at the surface and top of the atmosphere. The "spatial coherence method" (Coakley and Bretherton, 1982) is designed to address this problem by taking advantage of the "structure" amongst the pixels to retrieve percentage cloud cover. Using the 4 km AVHRR data, Dr. Coakley will derive empirical estimates of cloud cover and radiative properties for the Pacific and Atlantic Ocean basins from 50 degrees South to 50 degrees North. He will determine the effect of cloud geometry on its reflectivity, and assess the opacity of clouds at IR wavelengths and possible bias of the spatial coherence method. Dr. Coakley will also collaborate with ISCCP scientists to compare and contrast the results from two different approaches.