Assessment of the Potential Impact of a Hyperspectral Infrared Sounder on the Himawari Follow-On Geostationary Satellite

Abstract

To discuss the feasibility of the Himawari follow-on program, impacts of a hyperspectral sounder on a geostationary satellite (GeoHSS) is assessed using an observing system simulation experiment. Hypothetical GeoHSS observations are simulated by using an accurate reanalysis dataset for a heavy rainfall event in western Japan in 2018. The global data assimilation experiment demonstrates that the assimilation of clear-sky radiances of the GeoHSS improves the forecasts of the representative meteorological field and slightly reduces the typhoon position error. The regional data assimilation experiment shows that assimilating temperature and relative humidity profiles derived from the GeoHSS improves the heavy rainfall in the Chugoku region of western Japan as a result of enhanced southwesterly moisture flow off the northwestern coast of the Kyushu Island. These results suggest that the GeoHSS provides valuable information on frequently available vertically resolved temperature and humidity and thus improves the forecasts of severe events.

Impact of High Temporal Resolution FY‐4A Geostationary Interferometric Infrared Sounder (GIIRS) Radiance Measurements on Typhoon Forecasts: Maria (2018) Case With GRAPES Global 4D‐Var Assimilation System

“…Such studies also serve as pathfinders for the applications of future hyperspectral sounders in geostationary orbit. In addition, this work supports the OSSE studies of Li et al (2018), Okamoto et al (2020), and Wang et al (2021 to some extent using real measurements. They assessed the potential impacts of GEO hyperspectral IR sounders on NWP using an OSSE.…”

“…For example, Li et al (2018) demonstrated the added value from GEO hyperspectral IR sounder data for severe local storm forecasts in a regional Observing System Simulation Experiment (OSSE). Okamoto et al (2020) also explained the advantages of GEO satellite hyperspectral IR data for both regional and global NWP models. Using a hybrid OSSE, Wang et al (2021) demonstrated the improved local severe storm forecasts including atmospheric temperature, moisture, wind and precipitation forecasts when assimilating hyperspectral IR sounder data in a regional NWP.…”

A simulation-experiment-based assessment of retrievals of above-cloud temperature and water vapor using a hyperspectral infrared sounder

“…Such an approach may also enhance our understanding of convective impacts by providing timecontinuous observations (Li et al, 2018) in future research. The ability of the synergistic method to leverage hyperspectral infrared observations to improve NWP outputs (y atm ) also suggests that the inclusion of cloudy-sky observations in global data assimilation systems, as performed by Okamoto et al (2020), would be advantageous.…”

“…Our understanding of UTLS water vapor has long been informed by accurate in situ observations carried out during aircraft and balloon campaigns. Long-term records provided by balloon-borne observations have suggested a decadal increase in stratospheric water vapor (Oltmans et al, 2000;Rosenlof et al, 2001;Hurst et al, 2011) but a decadal cooling in tropical tropopause temperature over the same period (Rosenlof et al, 2001;Randel et al, 2004). These contradictory trends in water vapor and temperature are not reproduced well by reanalysis products (Davis et al, 2017), and the key processes at play are still under debate.…”

The Potential Impact of Assimilating Synthetic Microwave Radiances Onboard a Future Geostationary Satellite on the Prediction of Typhoon Lekima Using the WRF Model

“…The more realistic each of the OSSE components is, the more consistent the results will be with experiments using real observations [63]. Thus, the fifth generation of the ECMWF reanalysis (i.e., ERA-5) was used as a nature run or "true" atmospheric state in this study.…”