Description:
This document describes the GCM simulator-oriented ISCCP cloud product prepared to facilitate the evaluation of the model simulated clouds. This product is derived from the ISCCP D1 data (http://isccp.giss.nasa.gov ) which are quasi-instantaneous spatial averages of pixel-level retrievals over equal-area grid cells. Our GCM product represents monthly averages of a small subset of these observations. It is analogous to the ISCCP D2 monthly averages with the following differences:
These files were produced by Dr. Yuying Zhang at LLNL from equal-area data provided by Dr. Robert Pincus from University of Colorado. If you publish work that uses these data please contact us (zhang24@llnl.gov and Robert.Pincus@colorado.edu) for current citation information.
The simulator-oriented ISCCP cloud product is provided in CF-compliant netcdf format on a latitude-longitude grid. The current data cover the period July 1983 to June 2008. Each file includes the complete time series for a single variable.
The data files are:
The following variables are weighted by cloud fraction at each time:
The following files contain linear averages over time:
Grid-mean cloud albedo is determined from the grid-mean optical thickness (byte 92) in the ISCCP D1 using the analytic formula:
This is the approximation to the ISCCP lookup tables used in the ISCCP and is used by the ISCCP simulator to compute grid-box mean cloud albedo.
References:
- Rossow, W.B., and Schiffer, R.A., 1999: Advances in Understanding Clouds from ISCCP. Bull. Amer. Meteor. Soc., 80. [PDF], 27 pp.
- Rossow, W.B., A.W. Walker, D.E. Beuschel, and M.D. Roiter, 1996: International Satellite Cloud Climatology Project (ISCCP) Documentation of New Cloud Datasets*. WMO/TD-No. 737, World Meteorological Organization, 115 pp.
Exemple of plot:
Ftp CMOR data access: ISCCP
Matlab routine: isccp.m
Contact:
Please contact Dr. Yuying Zhang if you have any question or comments about GCM simulator Oriented ISCCP cloud product dataset.