The IPCC Data Distribution Centre Data File Format

Nomenclature

The files have been given an eight letter prefix and three letter suffix to make them compatible with all computers and media, thus the filename structure is:

AACCD122.xxx

AA = Experiment:	EE = ECHAM4; HH = HadCM2; GG = GFDL-R15; AA=CSIROMK2 and CC = CCCMA
CC = Forcing Details:	GG = Greenhouse Gas; GS = Greenhouse Gas and Aerosols
D= Scenario Details:	A = 1% per annum (IS92a); D = 0.5% per annum (IS92d)
1 =  Ensemble Member	1,2,3 or 4. X = Ensemble Mean
22 = Timeslice:	61 = 1961-1990; 20 = 2010-2039 (i.e. the 2020's); 50 = 2040-2069 (i.e. the 2050's);80 = 2070-2099 (i.e. the 2080's);
xxx= Variable Code	CLD = Cloud DTR = Diurnal Temperature Range PRE = Precipitation RAD = Radiation TMN = Mean Temperature TMP = Maximum Temperature TMX = Minimum Temperaure VAP = Vapour Pressure WND = Wind zip = Zipped file

Examples, therefore are:

EEGGA120.TMP represents Mean temperature change for the period 2010-2039 under IS92a Greenhouse Gas forcing scenario using ECHAM4.

HHGSD461.PRE represents Precipitation from ensemble member 4 for the period 1961-1990 under the IS92d greenhouse Gas and Sulphate forcing scenario using HadCM2.

GCM Grid Details - For the download files from the Green Pages

ECHAM4  Spectral Model T42 Resolution Grid 128*64 Aproximates to 2.8125 x 2.8125 degrees Starting Grid Cell Centred on: 0.00ºE 87.8638ºN Grid Details

HadCM2  Grid Box Model Grid 96*73 3.75 x 2.75 degrees Staring Grid Cell Centred on 0.00ºE 90.0ºN Grid Details

GFDL-R15  Spectral Model R-15 Resolution Grid 48*40 Aproximates to 7.5 x 4.5 degrees Starting Grid Cell Centred on 0.00ºE 86.598ºN Grid Details

CGCM1  Spectral Model T32 Resolution Grid 96 *48 Aproximates to 3.75 x 3.75 degrees Starting Grid Cell Centred on: 0.00ºE 87.1591ºN Grid Details

CSIRO-Mk2b Spectral Model R21 Resolution Grid 64*56 Aproximates to 5.625 x 3.214 degrees Starting Grid Cell Centred on: 0.00ºE 87.5613ºN Grid Details

Data Format

The format of the Scenario Download files is as follows. There is a six line header for each month, the codes for the header fields in italics (e.g. Model Name) are given below. The following is an example of the structure of the scenario data files.

IPCC-Data-Distribution-Centre-ModelName-Results---Date

Grid-is-xxx-*-yyy----Month-is-Jan

Mean-Change-values-for-year-year-with-respect-to-1961-1990

ForcingDetails---ExperimentCode

Variable-Name-(Units)

DataItems-----Format is 10f8.2---Missing-Value-is-9999.99

12.34	12.34	12.34	12.34	12.34	12.34	12.34	12.34	12.34	12.34
45.67	45.67	45.67	45.67	45.67	45.67	45.67	45.67	45.67	45.67
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.
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IPCC-Data-Distribution-Centre-ModelName-Results---Date

Grid-is-xxx-*-yyy----Month-is-Feb

Mean-Change-values-for-year-year-with-respect-to-1961-1990

ForcingDetails---ExperimentCode

Variable-Name-(Units)

Data Items-----Format is 10f8.2---Missing-Value-is-9999.99

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.
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IPCC-Data-Distribution-Centre-ModelName-Results---Date

Grid-is-xxx-*-yyy----Month-is-Dec

Mean-Change-values-for-year-year-with-respect-to-1961-1990

ForcingDetails---ExperimentCode

Variable-Name-(Units)

Data Items-----Format is 10f8.2---Missing-Value-is-9999.99

Codes for header Fields

Model Name	ECHAM4
	HadCM2
	GFDL-R15
	CCCMA
	CSIRO-Mk2b

Grid - Number of x Co-ordinates and Number of y Co-ordinates (e.g. 96 x 73)

Month - Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec

Year- Year - time slice data are for, e.g., 2010-2039

NOTE: For the period 1961-1990 the data are the actual values, for the 2010-2039, 2040-2069 and 2070-2099 the data are the changes with respect to the 1961-1990 period.

Forcing Details - GG = Greenhouse Gas: GS = Greenhouse Gas and Sulphate Aerosols; A = 1% per annum (IS92a); D= 0.5% per annum (IS92d); 1, 2, 3 or 4 represents the ensemble member or X = Ensemble mean.

Experiment Code -Refers to the first six characters of the file name (i.e., AACCD1)

Data Items - The product of xxx*yyy (e.g. 7008)