[M-SD35] Future Missions of Satellite Earth Observation

[MSD35-03] Global wind profiling with space-based Doppler wind lidar for improvement of numerical weather prediction

*Shoken Ishii¹, Kozo OKAMOTO², Hajime Okamoto³, Toshiyoshi Kimura⁴, Takuji Kubota⁴, Shunsuke Imamura⁴, Daisuke Sakaizawa⁴, youhei Okawa⁴, Koichi Fujihira⁴, Ayako Matsumoto⁵, Tsuyoshi Sekiyama², Tomoaki Nishizawa⁶, Tetsuya Takemi⁷, Yoshiaki Miyamoto⁸, Atsushi Sato⁹, Riko Oki⁴, Masaki Satoh¹⁰, Toshiki Iwasaki¹¹ (1.Tokyo Metropolitan University , 2.Japan Meteorological Agency / Meteorological Research Institute, 3.Kyushu University, 4.Japan Aerospace Exploration Agency, 5.ANA Holdings Incorporated, 6.National Institute for Environmental Studies, 7.Kyoto University, 8.Keio University, 9.Tohoku Institute of Technology, 10.University of Tokyo, 11.Tohoku University)

Keywords:3-D Global Wind Observation, Numerical Weather Prediction, Doppler Wind Lidar, Infrared Sounder, Earth Observation System

Analysis and prediction of atmospheric turbulence, convection, and dynamics phenomena are closely related to initial conditions of atmospheric conditions. An integrated global 3D observing system including wind observations with higher spatial resolution of smaller than 500 km is needed to understand atmospheric conditions in detail. The role of satellite observation systems is increasing year by year, and they are greatly contributing to the reduction of weather forecast errors. The WMO Integrated Global Observing System plan summarized by the WMO is important to promote continuously and effectively satellite observation systems, and to improve observation performance toward the next century. WMO summarizes requests from data users as requirements rolling review and opens the required observation performance as Observational System Capabilities Review Tool. Global observation systems did not make direct wind measurements in the oceans, tropics, or the Southern Hemisphere until the Aeolus installed a space-based Doppler wind lidar was launched by the European Space Agency (ESA) in August 2018. The Aeolus provided us global wind profiles from space. The Aeolus had two Rayleigh and Mie channels. The Rayleigh- and Mie-channel wind measurements were made under clear sky and cloudy conditions, respectively. Available wind data for the Mie-channel were limited in the clear sky and the atmospheric boundary layer. Although the Aeolus demonstrated the importance of the wind profile to improve the accuracy of numerical weather prediction, it ended its mission in July 2023 due to the design life. Currently, ESA is considering a next-generation DWL mission.
When we look at future satellite observing systems, satellite wind observing systems use tracking clouds or water vapor (atmospheric motion wind vector, AMV), which they rely on cloud or water vapor regions. AMV can observe over a wide area and at high frequency. AMV has problems such as height assignment, vertical resolution, observation accuracy, and wind measurement in clear/dry regions and limited layers. It is expected that AMV by a hyper-infrared sounder planned to be installed on the next geostationary meteorological satellite Himawari will improve these issues, but the height assignment issues by passive sensor observations remains. A satellite wind observing system capable of observation with high precision and high vertical resolution is required. In Japan, we have conducted feasibility studies of a space-based coherent Doppler wind lidar. Our goal is to realize high-resolution four-dimensional wind observation on a global scale by integrating with the wind observation by the Himawari, the next Aeolus, and other future satellite wind observing systems. This presentation is a proposal for a unique space-based Doppler wind lidar for the tropospheric wind measurement.