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CERES Computed Fluxes for Consistent Clouds



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 atmospheric conditions.
    • 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

Image: Computation of Modeled Fluxes & Consistent Input Variables Flowchart



Acronym Definition
AODAerosol Optical Depth
GEOSGoddard Earth Observing System
GMAOGlobal Modeling & Assimilation Office
hPahecto-Pascals
LWLongwave (~5um-200um)
MATCHModel for Atmospheric Chemistry & Transport
MODISModerate resolution Imaging Spectrometer
NCEPNational Center for Environmental Predication
OPACOptical Properties of Aerosols & Clouds
 
Acronym Definition
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

References

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). link to external site
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. link to external site
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.
http://dx.doi.org/10.1175/1520-0469(1993)050<2008:POTRPO>2.0.CO;2 link to external site

Jin, Z., T.P. Charlock, W.L. Smith, K. Rutledge,
2004: A Parameterization of Ocean Surface Albedo.
Geophysical Research Letters, 31, L.22301. http://dx.doi.org/10.1029/2004GL021180 link to external site

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. http://dx.doi.org/10.1175/JTECH-1694.1 link to external site

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, http://dx.doi.org/10.1029/2008JD010669 link to external site


CERES Data Product Information

 
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Page Last Modified: 10/16/2017 11:04:36 EST
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