EGUsphere

Copernicus Publications

Göttingen, Germany

10.5194/egusphere-2023-638

Shortwave reflected energy from NISTAR and the Earth Polychromatic Imaging Camera onboard the DSCOVR spacecraft

Weaver

Clark Jay

¹ ² Herman

Jay

https://orcid.org/0000-0002-9146-1632

¹ ³ Marshak

Alexander

⁴ Lorentz

Steven R.

⁵ Yu

Yinan

⁵ Smith

Allan W.

⁵ Szabo

Adam

⁶

Atmospheric Chemistry and Dynamics Branch, NASA Goddard Space Flight Center

Earth System Science Interdisciplinary Center (ESSIC), U. Maryland

Joint Center for Earth Systems Technology (JCET), U. Maryland

Climate and Radiation Laboratory, NASA Goddard Space flight Center

L-1 Standards and Technology, Inc., Manassas, VA US

Heliospheric Physics Laboratory, NASA Goddard Space flight Center

09 08 2023

2023 1 18

2023

This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/

This article is available from https://egusphere.copernicus.org/preprints/2023/egusphere-2023-638/

The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2023/egusphere-2023-638/egusphere-2023-638.pdf

We describe a new method for estimating the total reflected shortwave energy from the Earth Polychromatic Imaging Camera (EPIC) and compare it with direct measurements from the NIST Advanced Radiometer (NISTAR) instrument (Electrical substitution radiometer) – both are onboard the Lagrange-1 orbiting Deep Space Climate Observatory (DSCOVR). The 6 narrow-band wavelength channels (340 to 780 nm) available from EPIC provide a framework for estimating the integrated spectral energy for each EPIC pixel. The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) and the SCIAMACHY instrument provide spectral information away from the EPIC wavelengths, particularly for wavelengths longer than 780 nm. The total area-weighted reflected shortwave energy from an entire EPIC image is compared with co-temporal Band B Shortwave reflected energy observed by NISTAR. Our analysis from March to December 2017 shows the two are highly correlated with differences ranging from -10 to 10 Watts m-2. The offset bias over the entire period is less than 0.2 Watts m-2. We also compare our EPIC energy maps with the Clouds and the Earth’s Radiant Energy System (CERES) Single Scanner Footprint (SSF) Shortwave (SW) reflected energy observed within 3 hours of an EPIC image. Our EPIC-AVIRIS SW estimate is 5–20 % higher near the EPIC image center and 5–20 % lower near the image edges compared with the CERES SSF.