Measurement of precipitation at sea by NDBC moored buoys

Summary form only: Measurement of the precipitation that occurs at sea is of importance to further the understanding of global oceanographical and meteorological processes, air-sea interaction phenomena, and worldwide climatology. Large numbers of rainfall measurements are routinely made every day over the land areas of the world using rain gauges of standard design. Similar measurements over the ocean surface are sparse or nonexistent because adequate precipitation sensors are not readily available. Research and developmental efforts by the National Data Buoy Center during the nineteen eighties resulted in a rain gauge design that could be installed on deployed buoys and make accurate precipitation measurements at sea. The salient characteristics of the construction and operating principles of these rain gauges are briefly summarized. At present, NDBC is responding to a request by the NASA Goddard Space Flight Center to install precipitation sensors at sea using existing NDBC weather buoys. These measurement stations compute rainfall statistics and report them to shore via the buoy's satellite communication system. The precipitation data thus obtained are used by NASA to verify the measurement accuracy of rain-rate remote sensing radiometers carried by their Tropical Rainfall Measuring Mission (TRMM) satellite, a joint undertaking by the United States and Japan.