The Influence of Sub‐Footprint Cloudiness on Three‐Dimensional Horizontal Wind From Geostationary Hyperspectral Infrared Sounder Observations

Abstract

Radiance measurements from a geostationary hyperspectral infrared sounder (GeoHIS) with high temporal resolution not only provide a continuous weather cube of atmospheric temperature and moisture information at different pressure levels, but also enable derivation of three‐dimensional (3D) horizontal winds by tracking atmospheric water vapor features. However, GeoHIS radiances are influenced by sub‐footprint cloudiness, which needs to be considered in tracking the moisture features for deriving the atmospheric wind fields. By combining the collocated high spatial resolution cloud information from an imager onboard the same platform, the 3D horizontal wind retrievals can be improved, and the influence of sub‐footprint cloudiness on winds can be quantified for better applications. Using data from the Advanced Geostationary Radiation Imager (AGRI) and Geostationary Interferometric Infrared Sounder onboard the same experimental geostationary satellite Fengyun‐4A, it is found that 3D horizontal wind retrievals can be derived under both clear and partially clear skies with reasonable accuracy. Sub‐footprint cloud information provides noticeable improvement in wind retrievals; higher/lower clouds have more/less influence while thicker/thinner clouds have more/less influence, respectively, on the wind product. The sub‐footprint cloudiness (cloud‐top pressure and cloud coverage) provides a good indication of the quality flag for quantitative applications of the 3D horizontal wind product.

Applications of Geostationary Hyperspectral Infrared Sounder Observations: Progress, Challenges, and Future Perspectives

“…Usually, 3D horizontal winds can be derived under clear skies by tracking moisture movement (e.g., either in retrieved moisture profiles or radiances directly from two or more consecutive times). A recent study (Li et al 2022b) also indicated that the moisture tracked wind profiles can also be derived from measurements in partially cloud filled footprints, which increases the wind retrieval yield especially when the footprint size is relatively large (e.g., 16…”

Enhancing Clear Radiance Generation for Geostationary Hyperspectral Infrared Sounder Using High Temporal Resolution Information

“…J. Li, Zhang, et al. (2022) further concluded that if collocated Advanced Geosynchronous Radiation Imager (AGRI) data are used in conjunction with the 15‐min GIIRS data, the 3D winds can be further improved. Using 15‐min GIIRS data, Yin et al.…”

Added Value of Three‐Dimensional Horizontal Winds From Geostationary Interferometric Infrared Sounder for Typhoon Forecast in a Regional NWP Model

“…Concurrently, the United States contemplates introducing GeoHIS within the GeoXO program, aiming to enhance high temporal resolution observations of moisture and motion across North America and additional regions (Iturbide-Sanchez et al, 2022;Schmit et al, 2009). Notably, GeoHIS not only offers thermodynamic information in clear skies and hydrometeor information in cloudy conditions but can also provide dynamic filed observations with capability arising from its continuous tracking of changes in specific physical fields (Li, Zhang, et al, 2022). The most common satellite-derived winds are AMVs mentioned above.…”

“…Notably, GeoHIS not only offers thermodynamic information in clear skies and hydrometeor information in cloudy conditions but can also provide dynamic filed observations with capability arising from its continuous tracking of changes in specific physical fields (Li, Zhang, et al., 2022). The most common satellite‐derived winds are AMVs mentioned above.…”