3:30 PM - 3:45 PM
[AAS02-07] Challenges in measuring doppler velocities by spaceborne cloud and precipitation radars
Keywords:EarthCARE, Cloud Profiling Radar, PMM, Precipitation radar, Doppler velocity
Earth observation satellites can collect information over a broad area, periodically, with high consistency, in near real-time. On the other hand, estimating doppler velocities from space is very challenging because of satellite motion, velocity folding, and nonuniform beam filling. This paper introduces two future missions. One is the Earth Clouds, Aerosols and Radiation Explorer (EarthCARE) for measuring cloud vertical motion, and the other is the Precipitation Measuring Mission (PMM) for measuring precipitation vertical motion studied in the Japanese Aerospace Exploration Agency (JAXA).
The EarthCARE will have the first atmospheric radar in space with a doppler capability. The EarthCARE is a satellite that Japan and Europe have been jointly developing to observe clouds, aerosols and radiation (Illingworth et al. 2015). The EarthCARE satellite is aiming at a launch in 2023. Cloud Profiling Radar (CPR) with the doppler capability has been developed in the cooperation between the JAXA and the National Institute of Information and Communications Technology (NICT). Doppler velocity measured by the CPR is a key new variable in the EarthCARE. It is expected to provide information on terminal velocities of ice particles, drizzle, rain, and snow and insights into drizzle production and riming. Longer averaging will provide ice fall speed to provide a very useful constraint for global climate models, in which the radiation budget has been found to be very sensitive to the fall speed prescribed (Jakob 2002).
The JAXA has operated spaceborne precipitation radars since 1997 through Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and the Global Precipitation Measurement (GPM) Dual-Frequency Precipitation Radar (DPR). Japanese science community has discussed future precipitation observation mission from space based on the achievements from the TRMM and the GPM and expecting achievements from the EarthCARE and issued a mission proposal. According to user requirements, the JAXA has studied a feasibility of a higher sensitivity precipitation radar with the doppler capability. The JAXA has participated in NASA’s Aerosol, Could, Convection and Precipitation (ACCP) Pre-Phase A activities. In January 2022, the PMM Pre-Project Team was established in the JAXA for the JAXA Spacecraft carrying the Ku-band Doppler Precipitation Radar with the displaced phase center antenna (DPCA) approach. As the Ku-band Radar enables us retrievals in heavy precipitation, it is expected to provide unique information, in particular, over vigorously convective regions. Observations of the precipitation vertical motion will contribute to improvements of microphysics schemes in weather models.
The EarthCARE will have the first atmospheric radar in space with a doppler capability. The EarthCARE is a satellite that Japan and Europe have been jointly developing to observe clouds, aerosols and radiation (Illingworth et al. 2015). The EarthCARE satellite is aiming at a launch in 2023. Cloud Profiling Radar (CPR) with the doppler capability has been developed in the cooperation between the JAXA and the National Institute of Information and Communications Technology (NICT). Doppler velocity measured by the CPR is a key new variable in the EarthCARE. It is expected to provide information on terminal velocities of ice particles, drizzle, rain, and snow and insights into drizzle production and riming. Longer averaging will provide ice fall speed to provide a very useful constraint for global climate models, in which the radiation budget has been found to be very sensitive to the fall speed prescribed (Jakob 2002).
The JAXA has operated spaceborne precipitation radars since 1997 through Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) and the Global Precipitation Measurement (GPM) Dual-Frequency Precipitation Radar (DPR). Japanese science community has discussed future precipitation observation mission from space based on the achievements from the TRMM and the GPM and expecting achievements from the EarthCARE and issued a mission proposal. According to user requirements, the JAXA has studied a feasibility of a higher sensitivity precipitation radar with the doppler capability. The JAXA has participated in NASA’s Aerosol, Could, Convection and Precipitation (ACCP) Pre-Phase A activities. In January 2022, the PMM Pre-Project Team was established in the JAXA for the JAXA Spacecraft carrying the Ku-band Doppler Precipitation Radar with the displaced phase center antenna (DPCA) approach. As the Ku-band Radar enables us retrievals in heavy precipitation, it is expected to provide unique information, in particular, over vigorously convective regions. Observations of the precipitation vertical motion will contribute to improvements of microphysics schemes in weather models.