Eos, Transactions American Geophysical Union

Research Spotlight: Two eyes are better than one for measuring rain from space



[1] One predicted consequence of climate change is a global redistribution of precipitation and the resultant shifts in regional rainfall volumes. To forecast the details of Earth's changing climate, researchers rely on the accurate detection and measurement of rainfall volumes. One type of rain, the light, warm drizzle often found in coastal regions or during a spring shower, is especially difficult to measure using satellite observations. The two most promising techniques for measuring warm rain—passive microwave (PMW), which sees through clouds and measures the microwave radiation emitted by rain, and visible/near-infrared (VNIR) detection, which measures reflected sunlight at wavelengths up to near-infrared absorption bands of water—both have shortcomings. In their new study, Bennartz et al. try to marry the two techniques, using the strengths of each to improve the accuracy of warm rain detection. The researchers assessed the viability of using combined VNIR and PMW data with a simplified cloud model before testing their technique with satellite observations and independently observed precipitation data for a region along the western coast of South Africa. (Journal of Geophysical Research-Atmospheres, doi:10.1029/2009JD013679, 2010)