Comments on CERES Data

The CERES ES4 data product contains the "ERBE-like" temporally and spatially averaged shortwave (SW) and longwave (LW) top-of-the-atmosphere (TOA) fluxes derived from one month of CERES data from the Tropical Rainfall Measuring Mission (TRMM) spacecraft. Instantaneous TOA fluxes from the ES8 product have been spatially averaged on the same 2.5° equal-angle grid used by the Earth Radiation Budget Experiment (ERBE). Temporal interpolation algorithms identical to those used by ERBE have been applied to produce daily, monthly-hourly, and monthly mean fluxes from the instantaneous gridded data. The ES4 contains the temporally averaged values of TOA total-sky LW, total-sky SW, clear-sky LW, and clear-sky SW flux, total-sky albedo and clear-sky albedo for each 2.5° region observed during the month. In addition, the 2.5° regional means have been combined to produce 5° regional, 10° regional, 2.5° zonal, 5° zonal, 10° zonal, and global mean fluxes.

The quality of the CERES TRMM ES4 data is comparable to the quality of the ERBE ERBS single-satellite S4 data in terms of monthly regional, zonal, and global mean fluxes and scene identification. The major differences between CERES/TRMM and ERBE/ERBS are the field of view resolution, the spectral response of the instruments, the inclusion of rotating scanner plane data in the CERES product, and the tropical-only coverage of CERES/TRMM.

Data Accuracy Table

Errors from Temporal Interpolation and Spatial Averaging
  Mean Global Bias (Wm-2) Mean Regional 1 sigma (Wm-2)
Monthly Seasonal Monthly Seasonal
LW SW LW SW LW SW LW SW
All Latitudes
45°N - 40°S		 ±2
(0.8%)		 ±3
(3%)		 ±0.5
(0.2%)		 ±2.5
(3%)		 2-5
(<2%)		 8-11
(<12%)		 < 2
(<1%)		 < 6
(<7%)
Tropics
20° - 20°S		 ±1.5
(0.6%)		 ±3
(3%)		 ±0.4
(0.2%)		 ±2.5
(3%)		 < 3
(1.2%)		 < 8.5
(<9%)		 < 1.6
(<0.6%)		 < 5
(<6%)
Extratropical
45° > |Lat| > 20°		 ±3
(1.2%)		 ±3
(3%)		 ±0.8
(0.3%)		 ±2.5
(3%)		 < 6
(<2%)		 < 13
(<14%)		 < 2
(<1%)		 < 6
(<7%)
Science
Requirement		 2 - 5 2 - 5 2 - 5 2 - 5 10 10 10 10
For more information please consult the CERES ES4 Data Quality Summary Document.