MODIS/Terra Total Precipitable Water Vapor 5-Min L2 Swath 1km and 5km - NRT

The MODIS Adaptive Processing System (MODAPS) is currently generating an improved Collection 6.1 (061) for all MODIS Level-1 (L1) and higher-level Level-2 (L2) & Level-3 (L3) Atmosphere Team products. This decision to create a new improved Collection 6.1 (061) was driven by the need to address a number of issues in the current Collection 6 (006) Level-1B (L1B) data. These L1B issues had a negative impact in varying degrees in downstream products,

The MODIS level-2 atmospheric precipitable water product consists of total atmospheric column water vapor amounts (and ancillary parameters) over clear land areas of the globe, over extended clear oceanic areas with the Sun glint, and above clouds over both land and ocean. The shortname for this level-2 MODIS total precipitable water vapor product is MOD05_L2. In Collection 6, MODIS column water vapor (MOD05) datasets continue to be separately available from infrared and near-infrared methods.

The estimates based on a near-infrared algorithm uses only daytime measurements with solar zenith angle less than 72 degrees. The retrieval algorithm relies on observations of water vapor attenuation of near-infrared solar radiation reflected by surfaces and clouds. The product is produced only over areas that have reflective surfaces in the near-infrared. The near-infrared algorithm refinement for this product is no longer being supported by NASA and as such there has been no update to this algorithm for C6.1

MODIS自适应处理系统（MODAPS）目前正为所有MODIS一级（L1）及更高层次的二级（L2）与三级（L3）大气团队产品生成改进的第六版1.1（061）集合。此决策旨在创建新的改进版第六版1.1（061）集合，是由于解决当前第六版（006）一级B（L1B）数据中存在的一系列问题的需要。这些问题对下游产品产生了不同程度的负面影响。

MODIS二级大气降水水汽产品由全球清晰陆地区域、扩展的具有太阳光斑的清晰海洋区域以及陆地和海洋上空的云层中的总大气柱水汽量（及辅助参数）组成。该二级MODIS总降水水汽产品的简称是MOD05_L2。在第六版中，MODIS大气柱水汽（MOD05）数据集继续分别通过红外和近红外方法单独提供。

基于近红外算法的估计仅使用日间测量，且太阳天顶角小于72度。检索算法依赖于对由表面和云层反射的近红外太阳辐射中水汽衰减的观测。产品仅在具有近红外反射表面的区域内生成。由于NASA不再支持该产品的近红外算法改进，因此对于C6.1版本，此算法未进行更新。