Data Fusion of GEO FY-4A GIIRS and LEO Hyperspectral Infrared Sounders with Surface Observations: A Hong Kong Case Study

Abstract

Hyperspectral infrared satellite observations from geostationary platforms allow for the retrieval of temperature and water vapor measurements with higher temporal and vertical resolution than was previously available. The Chinese satellite, FY-4A includes the Geostationary Interferometric Infrared Sounder (GIIRS) which has the ability to measure vertical profiles of temperature and water vapor from space at times when ground-based upper air soundings are not available and can fill an important need in short-range weather prediction. In this study, CAPE and LI, which are used for forecasting atmospheric instability, were computed using the SHARPpy algorithm used by the NWS Storm Prediction Center. However, remote infrared and microwave sensing is lacking detailed information in the boundary layer, so the addition of the NOAA MADIS surface data may be necessary in order to get accurate temperature and moisture measurement near the surface. This study uses May 10-16, 2019 in the coastal region near Hong Kong for evaluating the use of hourly surface observations combined with satellite soundings from FY4A GIIRS at two hour intervals. The GIIRS plus MADIS surface-based CAPE and LI estimates are compared to estimates derived from low earth orbiting (LEO) SNPP and NOAA20 from NOAA, METOP from EUMETSAT, NWP reanalysis, and local radiosondes. In the case study, the two-hour sampling interval of the GIIRS geostationary sounder was able to capture the rapid transition (16 hours) from stable to unstable atmosphere in both CAPE and LI. The use of surface observations with satellite soundings gave mixed results, possibly due to the complex terrain near Hong Kong.

Comparison of the AIRS, IASI, and CrIS Infrared Sounders Using Simultaneous Nadir Overpasses: Novel Methods Applied to Data From 1 October 2019 to 1 October 2020

“…The AIRS, IASI, and CrIS high spectral resolution infrared sounders (hereafter simply referred to as “IR sounders”) comprise all that are being used by the U.S. operational system for medium‐range weather forecasting. These instruments, however, are also highly valuable in other types of applications, including nowcasting (e.g., Berndt et al., 2020; Bloch et al., 2019; Maier & Knuteson, 2022; W. L. Smith et al., 2020), climate trending (e.g., Brindley et al., 2015), climate model assessment (e.g., Della Fera et al., 2022) satellite intercalibration (Goldberg et al., 2011; Gyanesh et al., 2013), and trace gas retrievals (e.g., Payne et al., 2022; N. Smith & Barnet, 2020; Worden et al., 2022).…”

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

“…The possibility for passively remote sensing 3D horizontal winds is to use the radiance measurements from a hyperspectral infrared (IR) sounder with high temporal resolution, for example, the geostationary hyperspectral infrared sounder (GeoHIS) (Schmit et al, 2009). A GeoHIS can continuously observe changes in the atmospheric state over a fixed region (Lee et al, 2017;Maier & Knuteson, 2021), which is critical for monitoring, nowcasting and forecasting high impact weather (HIW) events (Li et al, 2011(Li et al, , 2012. Although hyperspectral IR sounders onboard the polar orbit satellites have provided global observations for NWP applications and climate studies, high temporal observations are limited to polar regions.…”