Computed Fluxes Description
- CERES executes a forward radiation transfer calculation at both CERES footprint and grid box spatial scale.
- Footprint & grid box calculations are archived in the "CRS" and "SYN" products respectively.
- Model results are archived at 5 levels in the atmosphere:
Top-of-Atmosphere (TOA), 70hPa, 200hPa, 500hPa and at the Earth's surface.
- After an initial run, modeled and observed TOA fluxes are compared, based on this difference, various model
inputs are adjusted to bring TOA calculations closer to CERES observations.
- This adjustment of input variables (or "tuning") allows for uncertainty in each relevant variable as a function
- For "clear sky" then, surface albedo, skin temperature, humidity may be adjusted.
- For "cloudy sky" situations, cloud fraction, height and optical depth may be adjusted.
- Assuming our uncertainty of input variables is larger than the uncertainty of the observed TOA fluxes, tuning
"pushes" the clouds and atmospheric state to be more consistent with respect to CERES observed fluxes.
Computation of Modeled Fluxes & Consistent Input Variables
|AOD||Aerosol Optical Depth |
|GEOS||Goddard Earth Observing System |
|GMAO||Global Modeling & Assimilation Office |
|LW||Longwave (~5um-200um) |
|MATCH||Model for Atmospheric Chemistry & Transport |
|MODIS||Moderate resolution Imaging Spectrometer |
|NCEP||National Center for Environmental Predication |
|OPAC||Optical Properties of Aerosols & Clouds ||
|p|| pressure level |
|q|| water vapor mixing ration |
|SBUV|| Solar Backscatter Ultra-Violet Radiometer |
|SW|| Shortwave (~0.2um-4.0um) |
|t|| temperature |
|TIROS|| Television Infrared Observation Satellites |
|TOA|| Top Of Atmosphere (0.1hPa) |
|TOVS|| TIROS Operational Vertical Sounder |
Charlock, T. P., F. G. Rose, D. A. Rutan, T. A. Alberta, D. P. Kratz, L. H. Coleman, G. L. Smith, N. M. Smith, and T. D. Bess,
1997: Clouds and the Earth's Radiant Energy System (CERES) Algorithm Theoretical
Basis Document: Compute Surface and Atmospheric Fluxes (Subsystem 5).
CERES Subsystem 5.0 Algorithm Theoretical Basis Document
Charlock, T. P., F. G. Rose, D. A. Rutan, Z. Jin, and S. Kato,
2006: The Global Surface and Atmosphere Radiation Budget: An Assessment of Accuracy with 5 years of Calculations and Observations.
Proceedings of 12th Conference on Atmospheric Radiation (AMS), 10-14 July 2006, Madison, Wisconsin.
Fu, Q., and K-N. Liou,
1993: Parameterization of the radiative properties of cirrus clouds.
Journal of Atmospheric Sciences, 50, 2008-2025.
Jin, Z., T.P. Charlock, W.L. Smith, K. Rutledge,
2004: A Parameterization of Ocean Surface Albedo.
Geophysical Research Letters, 31, L.22301.
Kato, S., F.G., Rose, and T.P., Charlock,
2005: Computation of Domain-Averaged Irradiance Using Satellite-Derived Cloud Properties.
Journal of Atmospheric Oceanic Technology, 22b, pp 146-164.
Rose, F., T. Charlock, D. Rutan & G. Smith,
1997: Tests of a constrainment algorithm for the surface and atmospheric radiation budget.
Proceedings of 9th Conference on Atmospheric Radiation (AMS), 2-7, February, 1997, Long Beach, California.
Rutan, D., F. Rose, M. Roman, N. Manalo-Smith, C. Schaaf, and T. Charlock
2009: Development and assessment of broadband surface albedo from Clouds and the Earth's Radiant Energy System Clouds
and Radiation Swath data product.
Journal of Geophysical Research, 114, D08125,
CERES Data Product Information