Validation of Near-Real-Time NOAA-20 CrIS Outgoing Longwave Radiation with Multi-Satellite Datasets on Broad Timescales

Tianyuan Wang,Ken Pryor,Juying Warner,Nicholas R Nalli,Changyi Tan,Murty Divakarla,Mitch Goldberg,Zigang Wei,Lihang Zhou

doi:10.3390/rs13193912

Abstract

The Outgoing Longwave Radiation (OLR) package was first developed as a stand-alone application, and then integrated into the National Oceanic and Atmospheric Administration (NOAA) Unique Combined Atmospheric Processing System (NUCAPS) hyperspectral sounding retrieval system. An objective of this package is to provide near-real-time OLR products derived from the Cross Track Infrared Sounder (CrIS) onboard the Joint Polar Satellite System (JPSS) satellites. It was initially developed and validated with CrIS onboard the Suomi National Polar-orbiting Partnership (SNPP) satellite, and has been expanded to JPSS-1 (renamed NOAA-20 after launch) datasets that are currently available to the public. In this paper, we provide the results of detailed validation tests with NOAA-20 CrIS for large and wide representative conditions at a global scale. In our validation tests, the observations from Clouds and Earth’s Radiant Energy System (CERES) on Aqua were treated as the absolute reference or “truth”, and those from SNPP CrIS OLR were used as the transfer standard. The tests were performed on a 1°×1° global spatial grid over daily, monthly, and yearly timescales. We find that the CrIS OLR products from NOAA-20 agree exceptionally well with those from Aqua CERES and SNPP CrIS OLR products in all conditions: the daily bias is within ±0.6 Wm−2, and the standard deviation (STD) ranges from 4.88 to 9.1 Wm−2. The bias and the STD of OLR monthly mean are better, within 0.3 and 2.0 Wm−2, respectively. These findings demonstrate the consistency between NOAA-20 and SNPP CrIS OLR up to annual scales, and the robustness of NUCAPS CrIS OLR products.

Highlights

Outgoing longwave radiation (OLR) is an essential contributor to the Earth radiation budget (ERB) at the top of the atmosphere (TOA), and is critical for understanding climate change, because the imbalance between the energy loss due to OLR and that from the Absorbed Solar Radiation at TOA is known to be a radiative forcing and a driver of climate change [1,2]
We report our work on the validation of the NOAA-Unique Combined Atmospheric Processing System (NUCAPS) National Oceanic and Atmospheric Administration (NOAA)-20 Cross Track Infrared Sounder (CrIS)
As described in the previous section, our validation analysis was performed with three different OLR products: the Aqua Clouds and Earth’s Radiant Energy System (CERES) OLR, the Suomi National Polar-orbiting Partnership (SNPP) CrIS OLR, and the NOAA-20 CrIS OLR

Summary

Introduction

Outgoing longwave radiation (OLR) is an essential contributor to the Earth radiation budget (ERB) at the top of the atmosphere (TOA), and is critical for understanding climate change, because the imbalance between the energy loss due to OLR and that from the Absorbed Solar Radiation at TOA is known to be a radiative forcing and a driver of climate change [1,2]. OLR has been widely used in climate sensitivity studies, diagnoses, and predictions [3]. It is used as a proxy for deep convection and precipitation, and as an indicator of cloudiness, tropical, and monsoon variability [3]. Its applications are found in studies of El Niño/La Niña variability [4] and, more recently, of earthquakes [5]. These atmospheric and geodynamic processes occur in wide ranges of spatial-temporal scales.

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Discussion

Conclusion