Yan, H, Yang, S (2007). A MODIS dual spectral rain algorithm. JOURNAL OF APPLIED METEOROLOGY AND CLIMATOLOGY, 46(9), 1305-1323.
The Moderate Resolution Imaging Spectroradiometer (MODIS) dual spectral rain algorithm (MODRA) is developed for rain retrievals over the northern midlatitudes. The reflectance of the MODIS water vapor absorption channel at 1.38 mu m (R-1.38 mu m) has a potential to represent the cloud-top height displayed by the brightness temperature (TB) of the MODIS channel at 11 mu m, because of an excellent negative relationship (correlation coefficient <=-0.9) between R-1.38 mu m and TB11 mu m for optically thick clouds with reflectance (R-0.65 mu m) greater than 0.75. With a training rainfall dataset from the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) aboard the same Aqua satellite platform, two MODIS channels (R-1.38 mu m and R-0.65 mu m) are applied to form multiregression curves to estimate daytime rainfall. Results demonstrate that the instantaneous rain rates from MODRA, independent AMSR-E rainfall products, and surface rain gauge measurements are consistent. This study explores a new way to estimate rainfall from MODIS water vapor and cloud channels. The resulting technique could be applied to other similar satellite instruments for rain retrievals.