Optimized MODIS channel selection to improve the NASA CERES FluxByCloudTyp product fluxes

David R. Doelling; Moguo Sun; Forrest J. Wrenn

doi:10.1117/12.2600060

12 September 2021 Optimized MODIS channel selection to improve the NASA CERES FluxByCloudTyp product fluxes

David R. Doelling, Moguo Sun, Forrest J. Wrenn

Proceedings Volume 11859, Remote Sensing of Clouds and the Atmosphere XXVI; 118590F (2021) https://doi.org/10.1117/12.2600060
Event: SPIE Remote Sensing, 2021, Online Only

Abstract

The NASA Clouds and the Earth’s Radiant Energy System (CERES) project has provided the climate community more than a 20-year record of top of the atmosphere (TOA) reflected shortwave (SW) and emitted longwave (LW) fluxes. The fluxes are used to monitor the Earth’s energy balance as well as for climate model validation and cloud feedback studies. One of the largest uncertainties in climate models is the response of clouds in feedback studies. Reducing this uncertainty requires a more stringent validation of model-generated fluxes by cloud-type. Rather than relying on radiative transfer model generated fluxes from observed cloud-type retrievals, the CERES FluxByCloudTyp (FBCT) product relies on MODIS empirical narrowband to broadband relationships to convert the cloudy portions of the CERES footprints into fluxes. The overcast footprint and sub-footprint cloud layer fluxes are then stratified by 7 pressure layers and 6 optical depth bins and temporally averaged into daily and monthly regional cloud-type fluxes. The CERES project analyzed a total of 19 MODIS channels for use in the next generation FBCT product narrowband to broadband conversion. This was accomplished by comparing the narrowband to broadband RMS errors from all possible 5-channel combinations. The SW and LW optimized channels were selected by also considering analogous geostationary, MODIS and VIIRS imager channels as well as channel combinations that provided the lowest RMS errors across all surface types. The optimized channel combinations will be tested in the FBCT algorithm to investigate any narrowband to broadband dependencies as a function of cloud fraction, effective pressure, optical depth, PW, solar and view angle, surface type.

Conference Presentation

Citation Download Citation

David R. Doelling, Moguo Sun, and Forrest J. Wrenn "Optimized MODIS channel selection to improve the NASA CERES FluxByCloudTyp product fluxes", Proc. SPIE 11859, Remote Sensing of Clouds and the Atmosphere XXVI, 118590F (12 September 2021); https://doi.org/10.1117/12.2600060

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available