Wakasa Bay Precipitation Experiment (WBAY) 2003

In response to the need to estimate rainfall for both climate prediction and severe weather forecasting, ETL has developed a sensor for accurate calibration of existing and planned satellite microwave rainfall instruments. The sensor, based on the ETL Polarimetric Scanning Radiometer (PSR) system, is the first airborne conical-scanning radiometer system, and is able to image rainfall in regions inaccessible by WSR-88D or other land-based rain radars. The system was first flown for rainfall measurement in 1998 and provided images of the rainbands of Hurricane Bonnie at landfall on the North Carolina coastline. As the result of a joint U.S.-Japanese collaboration involving NOAA, NASA, and the Japanese Space Agency NASDA, the PSR is providing data for calibration of the NASA-NASDA AMSR-E sensor on the NASA Aqua satellite over the Sea of Japan and Pacific coastal region east of Japan. Currently, NOAA/NESDIS plans to use the AMSR-E data in operational algorithms and as a means of improving rainfall algorithms in preparation for the launch of NPOESS at the end of the decade.

Data from high-resolution airborne instruments such as the PSR is critical for both on-orbit assessment of the performance of sensors such as AMSR-E, AMSU, and CMIS, as well as improving the accuracy of operational satellite rainfall algorithms. The resolution of the PSR is at least a factor of ten greater than that of satellites, and thus provides a means of resolving the structure of rain-producing frontal systems that are otherwise impossible to observe from space. Improved rainfall estimation is essential for quantitative precipitation forecasting (e.g., flash flood, hurricanes at landfall, other high-impact weather such as coastal storms), drought monitoring and prediction, and global climate change assessment.