The Japan Meteorological Agency (JMA) began operational use of data from the AMSR3 sensor on 8 September 2026. The sensor is installed on the IBUKI GW (GOSAT-GW) satellite, which was launched by the Japanese space agency JAXA in June 2025.
AMSR3 measures microwaves emitted by the Earth’s surface, atmospheric water vapour, clouds and precipitation, including snow. The two agencies worked together to make use of this data as early as possible and confirmed that it improves the accuracy of water vapour analyses and forecasts in numerical models.
Rainfall forecasts are therefore expected to become more precise. In an example from September 2025, the forecast without AMSR3 underestimated rain in south-western Hokkaido, while the one including the new data came closer to what was observed.
The JMA was already using this data to analyse sea temperature and sea ice, information that is useful for fishing and for choosing safe shipping routes. JAXA and the JMA will continue working to make even greater use of satellite observations.
