Extending and enhancing the satellite precipitation data record from passive microwave sensors

Passive microwave (PMW) observations form the backbone of global precipitation measurements due to their relative directness of precipitation retrievals compared to those in the visible/infrared. The NASA/JAXA Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement (GPM) missions have been central to advancing satellite precipitation measurements since TRMM was launched in 1997. Prior to TRMM, PMW estimates were derived primarily using observations from the US Defense Meteorological Satellite Program (DMSP) Special Sensor Microwave/Imager (SSM/I) sensors, first launched in 1987. The PMW data records preceding the SSM/I era are extremely important for providing long term precipitation measurements. Data from earlier missions could potentially extend the satellite precipitation data record back to 1973 and is therefore highly desirable, although these precipitation-capable sensors have not been fully exploited. Furthermore, while current PMW precipitation retrievals utilize a range of observations from both cross-track ‘sounders’ and conically scanning ‘imaging’ sensors, not all the available observations from these sensors are presently exploited.

This poster outlines the fundamental requirements of improving our measurements of global precipitation through exploiting and enhancing current and past precipitation-capable missions and their data using conventional and new methodologies. In particular, the different channel availability is shown to significantly affect the ability to provide accurate precipitation retrievals which impacts the generation of a consistent climate precipitation record. Extending the precipitation data record and fully exploiting the available observations has the potential to improve our knowledge of the Earth System and its’ water cycle, provide a greater understanding of our changing global climate, and gain better insights into the naturally occurring and human-induced changes.