Dr. Aonashi received the B.S. degree in meteorology from the Meteorological College, Kashiwa, Chiba, in 1982, and the Sc. D. degree in meteorology from University of Tokyo in 1997.

After graduated from the Meteorological College, he worked with Japan Meteorological Agency (JMA). From 1988, he has been working for the Meteorological Research Institute (MRI), JMA. From 2011, he has been the head of the 1st laboratory of the Typhoon Research Department of MRI.

His areas of expertise are in assimilation of satellite microwave radiometer data into cloud-resolving models (CRMs) and passive microwave precipitation retrievals. He has been engaging in the Global Satellite Mapping of Precipitation (GSMaP) project and developing passive microwave precipitation algorithms for TRMM, GPM and GCOM-W. He has also been participating in "Strategic Program for Innovative Research (SPIRE), Field 3 (Japan Agency for Marine-Earth Science and Technology)" as a developer of data assimilation methods for CRMs.