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GCM Data File Format

Nomenclature

The files you download are gzipped tar archives, (programs such as Stuffit Expander and WinZip can open these archives). The archives for the 1960-91 period contain one file each. The mean and change archives that you download contain three files, one for each of the reference periods (2010-39, 2040-69 and 2070-99)

The nomenclature used for the files is:

AAAAA_BBb_varname_DDDD.mea

AAAAA = Experiment: EE = ECHAM4; HH = HadCM2; GG = GFDL-R15; AA=CSIROMK2; CC = CCCMA;
NN=NCAR-DOE and JJ=CCSR/NIES
BB= Scenario Details:  e.g. A2 = SRES A2 integration
a =  Ensemble Member a,b,c, etc. X = Ensemble Mean 
varname = Variable Code

Note: Not all variables are available from all runs 

CPRAT Convective Precipitation (mm/day)
DSWF=Total Incident Solar Radiation (w/m2)
HGT500=500 hPa Height (gpm)
HGTVAR500 = 500 hPa height variance (gpm)
MSLP = Mean Sea Level Pressure (hPa)
PREC = Total Precipitation (mm/day)
PRECC = Convective Precipitation (mm/day)
PRECL = Large Scale Precipitation (mm/day)
SICE = Sea Ice (kg/m2)
SMC = Soil Moistur Content (mm)
SN = Snow Depth (m)
SPFH = Specific Humidity (kg/kg)
SPFH200 = 200 hPa Specific Humidity (kg/kg)
SPFH500 = 500 hPa Specific Humidity (kg/kg)
SPFH850 = 850 hPa Specific Humidity (kg/kg)
TEMPVAR = Screen Temperature Variance (k2)
TMAX = Maximum Temperature (C)
TMIN = Minimum Temperature (C)
TMP = Mean Temperature (C)
TMP200 = 200 hPa Mean Temperature (C)
TMP500 = 500 hPa Mean Temperature (C)
TMP850 = 850 hPa Mean Temperature (C)
TS = Surface Skin Temperature/SST (k)
UGRD200 = 200 hPa u-Wind (m/g)
UGRD500 = 500 hPa u-Wind (m/g)
UGRD850 = 850 hPa u-Wind (m/g
UVAR200 = 200 hPa u-Wind Variance (m/g)
VGRD200 = 200 hPa v-wind (m/g)
VGRD500 = 500 hPa v-wind (m/g)
VGRD850 = 850 hPa v-wind (m/g)
VVAR200 = 200 hPa v-Wind Variance (m/g)
VAP = Vapour Pressure
WIND = Mean Scalar Wind Speed (m/s)
DDDD= timeslice

1980 = 1961-1990; 2020 = 2010-2039 (i.e. the 2020's); 2050 = 2040-2069 (i.e. the 2050's);2080 = 2070-2099 (i.e. the 2080's); 

xxx=

mea = monthly mean, dif = change fields

Therefore CCCma_B2a_DSWF_2020mea.tar.gz contains represents Mean temperature change for the period 2010-2039 under B2 scenario for the first integration Greenhouse Gas forcing scenario using CGCM1.

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

ECHAM4 
Spectral Model
T42 Resolution
Grid 128*64
Approximates to 2.8125 x 2.8125 degrees
Grid Details
HadCM3 
Grid Box Model
Grid 96*73
3.75 x 2.5 degrees
Staring Grid Cell Grid Details
GFDL-R30 
Spectral Model
R-30 Resolution
Grid 96*80
Approximates to 3.75 x 2.25 degrees
Grid Details
CGCM1 
Spectral Model
T32 Resolution
Grid 96 *48
Approximates to 3.75 x 3.75 degrees
Grid Details
CSIRO-Mk2b
Spectral Model
R21 Resolution
Grid 64*56
Approximates to 5.625 x 3.214 degrees
Grid Details
NCAR-DOE
Spectral Model
R-15 Resolution
Grid 48*40
Approximates to 7.5 x 4.5 degrees
Grid Details
CCSR/NIES
Spectral Model
T21 Resolution
Grid 64x32
Approximates to 5.625x 5.625 degrees
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
 .                  
 .                  
 .                  
 .                  

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

 .                  
 .                  
 .                  
 .                  

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  
  HadCM3  
  GFDL-R30  
  CCCMA  
  CSIRO-Mk2b  
  NCAR-DOE  
  SELECTION-->CCSR/NIES /SELECTION-->  

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) floating point values, starting with the most northerly row ordered from west to east.

 

Content last modified: 01 September 2014