Global clear-sky surface skin temperature from multiple satellites using a single-channel algorithm with angular anisotropy corrections

Abstract

Abstract. Surface skin temperature (T s ) is an important parameter for characterizing the energy exchange at the ground/water-atmosphere interface. The Satellite ClOud and Radiation Property retrieval System (SatCORPS) employs a single-channel thermal-infrared (TIR) method to retrieve T s over clear-sky land and ocean surfaces from data taken by geostationary Earth orbit (GEO) and low Earth orbit (LEO) satellite imagers. GEO satellites can provide somewhat continuous estimates of T s over the diurnal cycle in non-polar regions, while polar T s retrievals from LEO imagers, such as the Advanced Very High Resolution Radiometer (AVHRR), can complement the GEO measurements. The combined global coverage of remotely sensed T s , along with accompanying cloud and surface radiation parameters, produced in near-realtime and from historical satellite data, should be beneficial for both weather and climate applications. For example, near-realtime hourly T s observations can be assimilated in high-temporal-resolution numerical weather prediction models and historical observations can be used for validation or assimilation of climate models. Key drawbacks to the utility of TIR-derived T s data include the limitation to clear-sky conditions, the reliance on a particular set of analyses/reanalyses necessary for atmospheric corrections, and the dependence on viewing and illumination angles. Therefore, T s validation with established references is essential, as is proper evaluation of T s sensitivity to atmospheric correction source.This article presents improvements on the NASA Langley GEO satellite and AVHRR TIR-based T s product that is derived using a single-channel technique. The resulting clearsky skin temperature values are validated with surface references and independent satellite products. Furthermore, an empirically adjusted theoretical model of satellite land surface temperature (LST) angular anisotropy is tested to improve satellite LST retrievals. Application of the anisotropic correction yields reduced mean bias and improved precision of GOES-13 LST relative to independent Moderateresolution Imaging Spectroradiometer (MYD11_L2) LST and Atmospheric Radiation Measurement Program ground station measurements. It also significantly reduces intersatellite differences between LSTs retrieved simultaneously from two different imagers. The implementation of these universal corrections into the SatCORPS product can yield significant improvement in near-global-scale, near-realtime, satellite-based LST measurements. The immediate availability and broad coverage of these skin temperature observations should prove valuable to modelers and climate researchers looking for improved forecasts and better understanding of the global climate model.

Land Surface Temperature from GOES-East and GOES-West

“…To explore such variability, there is a need to establish a consistent and seamless long-term global record of land surface properties, which requires to homogenize satellite observations from several sources (e.g., Pinheiro et al 2006;Susskind and Blaisdell 2008;Seemann et al 2008;Anderson et al 2011;Hulley and Hook 2011;Ermida et al 2017Ermida et al , 2018Ermida et al , 2020. For instance, Scarino et al (2013Scarino et al ( , 2017) used a single-channel thermal-infrared (TIR) method to retrieve surface LST under clear-sky from geostationary-Earth-orbit (GEO) and low-Earth-orbit (LEO) satellite imagers. They used an empirically adjusted theoretical model of angular anisotropy (Vinnikov et al 2012) to improve the satellite LST retrievals.…”

Evaluating the Magnitude of VIIRS Out-of-Band Response for Varying Earth Spectra

“…Well-characterized spectral performance is critical to the reliable on-orbit operation of Earth-monitoring instruments, whether for routine measurements or for climate studies, and also lends confidence to radiometric calibration efforts and the products reliant on them [1,2]. The Clouds and the Earth's Radiant Energy System (CERES) project, for instance, relies on RSR-dependent calibration adjustments and atmospheric transmissivity calculations to produce accurate cloud products for consistent flux measurements [3][4][5][6][7]. As such, complete pre-launch evaluation of sensor geometric performance, including RSR co-registration and spatial response characterization, is a necessary requirement established to meet the goals of the remote sensing community [8][9][10][11][12][13].…”

Towards a Unified and Coherent Land Surface Temperature Earth System Data Record from Geostationary Satellites

“…The Land Surface Diurnal Temperature Range (DTR) is an important element of the climate system and is not captured by the polar orbiting satellites. Geostationary satellites provide diurnal coverage and observe the surface continuously at a nadir pixel resolution of about 4 km [32] which led to the development of several algorithms for GEO satellites [33][34][35].…”