[M-SD35] Future Missions of Satellite Earth Observation

[MSD35-06] 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, Tadashi Imai⁴, Daisuke Sakaizawa⁴, Masakatsu Nakajima⁴, Ayako Matsuomto⁵, Thomas T 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:Earth Observation System, Doppler Wind Lidar, 3-D Global Wind Observation, Numerical Weather Prediction, Infrared Sounder

Earth observation satellites (EOSs) currently observe various Essential Climate Variables (ECVs) for forecasting weather and understanding and monitoring the climate system. EOSs are indispensable infrastructure for modern society. Various data obtained through earth observation are not only scientifically valuable but also economically significant assets. Among the ECVs, a focus on wind observation satellites reveals that most of them are dedicated to observing ocean winds or tracking winds using clouds or water vapor (atmospheric motion wind vectors, AMV). The atmospheric motion wind vectors depend on the presence of cloud or water vapor regions. The atmospheric motion wind vectors can observe over a wide area and at high frequency. However, they face challenges such as altitude estimation, vertical resolution, observation accuracy, and wind measurement in clear or dry regions, as well as in limited atmospheric layers. The atmospheric motion wind vectors observed using a hyper-infrared sounder, planned for installation on the next geostationary meteorological satellite Himawari, are expected to improve performance of the issues. However, altitude estimation through passive sensor observations remains a challenge due to inherent limitations. A satellite wind observation system capable of high-precision and high-vertical-resolution measurements is required.
In August 2018, the European Space Agency launched the wind observation satellite Aeolus carrying a direct-detection Doppler wind lidar to improve global wind initial conditions for numerical weather prediction, as well as enhancing the understanding and modeling of atmospheric dynamics at global and regional scales. The Aeolus observed global wind vertical distributions from space and demonstrated the significance of vertical wind observations and the utility of Doppler wind lidar in improving numerical weather prediction accuracy and atmospheric dynamics applications. The Aeolus ended the mission due to the design life in July 2023. The European Space Agency are considering a next-generation DWL mission. In Japan, we have been conducting feasibility studies of a space-based coherent Doppler wind lidar. We have initiated the development of a new simulator designed to evaluate the wind measurement performance of both the heterodyne-detection detection method and the direct detection method, the latter of which is employed in the Aeolus 1 and follow-up missions. Additionally, we are developing algorithms for atmospheric motion vector and altitude estimation by leveraging AI technologies. The presentation is a proposal for a unique space-based Doppler wind lidar for the tropospheric wind measurement. 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.