Improvement in tropospheric moisture retrievals from VIIRS through the use of infrared absorption bands constructed from VIIRS and CrIS data fusion

E Eva Borbas,Elisabeth Weisz,Chris Moeller,Bryan A Baum,W Paul Menzel

doi:10.5194/amt-14-1191-2021

Abstract

Abstract. An operational data product available for both the Suomi National Polar-orbiting Partnership (S-NPP) and National Oceanic and Atmospheric Administration-20 (NOAA-20) platforms provides high-spatial-resolution infrared (IR) absorption band radiances for Visible Infrared Imaging Radiometer Suite (VIIRS) based on a VIIRS and Crosstrack Infrared Sounder (CrIS) data fusion method. This study investigates the use of these IR radiances, centered at 4.5, 6.7, 7.3, 9.7, 13.3, 13.6, 13.9, and 14.2 µm, to construct atmospheric moisture products (e.g., total precipitable water and upper tropospheric humidity) and to evaluate their accuracy. Total precipitable water (TPW) and upper tropospheric humidity (UTH) retrieved from hyperspectral sounder CrIS measurements are provided at the associated VIIRS sensor's high spatial resolution (750 m) and are compared subsequently to collocated operational Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) and S-NPP VIIRS moisture products. This study suggests that the use of VIIRS IR absorption band radiances will provide continuity with Aqua MODIS moisture products.

Highlights

Retrieval of atmospheric water vapor properties from the Visible Infrared Imaging Radiometer Suite (VIIRS) satellite sensor on the Suomi National Polar-orbiting Partnership (S-NPP) and the National Oceanic and Atmospheric Administration-20 (NOAA-20) platforms is challenging due to the absence of infrared (IR) water vapor absorption bands.measurements in the missing spectral region are available on the Crosstrack Infrared Sounder (CrIS), a hyperspectral IR sensor on the same platforms
With the addition of the missing spectral bands to VIIRS on S-NPP, this study evaluates total column precipitable water vapor (TPW) and upper tropospheric humidity (UTH) in clear skies through comparison to the Moderate Resolution Imaging Spectroradiometer (MODIS) MYD07 (Borbas et al, 2017) and MYD08 (Platnick et al, 2017) Collection 6.1 and version 1.0 VIIRS (Borbas et al, 2019a–d) atmospheric products
The absence of water vapor and CO2 absorption IR spectral bands on the VIIRS imager on the S-NPP and National Oceanic and Atmospheric Administration-20 (NOAA20) polar-orbiting platforms limits the capability for tropospheric moisture retrievals, especially for upper tropospheric moisture

Summary

Introduction

Retrieval of atmospheric water vapor properties from the Visible Infrared Imaging Radiometer Suite (VIIRS) satellite sensor on the Suomi National Polar-orbiting Partnership (S-NPP) and the National Oceanic and Atmospheric Administration-20 (NOAA-20) platforms is challenging due to the absence of infrared (IR) water vapor absorption bands. Measurements in the missing spectral region are available on the Crosstrack Infrared Sounder (CrIS), a hyperspectral IR sensor on the same platforms. Spectral measurements in these IR absorption bands can be constructed for VIIRS through fusion of the imager and sounder data. The VIIRS+CrIS fusion radiances are available for the entire record of both the S-NPP and NOAA-20 platforms (Baum et al, 2019a) The availability of these IR-band radiances for VIIRS at 750 m pixel resolution makes it possible to retrieve a cloud mask and moisture properties using algorithms developed and tested using the full MODIS spectral band suite (Borbas et al, 2011).

Data and methodology

TPW and UTH algorithm and results

TPW results

UTH results

Findings

Summary and conclusions