ArcticRIMS Data Format


At the January, 2001 UNH ArcticRIMS Meeting we decided on a standardized format for storing and exchanging data on the EASE-Grid for the pan-Arctic. Data for the 39926 grid cells must be stored in "RIMS Format". The following is a description of the format details for daily and monthly data.

Daily Data

Filename:   varname.YYYY.MM.txt

where:      varname is the name of the variable (something informative)
            YYYY    is the four digit year
            MM      is the 2 digit month

example:    Precipitation.1999.02.txt  represents Precipitation data for 
            February, 1999.

File content:

line 1      YYYY MM free form comment which includes units
line 2      "CellID" "Lat" "Long" "01" "02" "03" "04" "05" "06" "07" "08" "09" "10" "11" "12" "13" "14" "15" "16" "17" "18" "19" "20" "21" "22" "23" "24" "25" "26" "27" "28" "29" "30" "31"
line 3           (data lines here to end of file)
line 4                        ...
line 5                        ...
...                           ...
...                           ...
line 39927                    ...
line 39928                    ...


example file:  precipitation.1999.09.txt

The first two lines are reserved for header information.  The first line should contain the year 
and month, followed by a short description of the data (inluding units!).  
Line 2 is header as described below. Surrounding each parameter in line two of the header with double
quotes and a space would be most helpful. Lines 3-39928 contain the data. Having at least one space between 
each column is optimal. 

RIMS members should record their data (eg., 31f8.1) to as many decimal places as needed.

All files should have 34 columns regardless of the number of days in the month.


Line 1    Contains Three items:

YYYY      The year in four digits 

MM        The month in two digits (e.g. August = 08)

comment   This is a free form comment line for information deemed appropriate.
          Units are required here.



Line 2    Contains column names for the data

"CellID"  The EASE-GRID cell ID.

"Lat"     Latitude in the range 0-90 where 0 is the equator and 90 is the north pole.
          Decimal degrees with a minimum of 4 decimals is required.

"Long"    Longitude in the range 0-360 where Long = 0 is Greenwich and Long = 180
          is 180 degrees E or W.  To convert to -180 to 180 deg Longitude you can use the
	  following line of C code:

	  	if (Long > 180)
			Long = Long-360;

          Decimal degrees with a minimum of 4 decimals is required.

"01"      Data values for the first day of the month.  In most cases these data will 
          be floating point with an appropriate number of decimal places.  Some data
          such as vegetation type or rain/no rain will be integer.

"02"      Data values for the second day of the month

...

...

"30"      Data values for the 31st day of the month.  If there is no 30th day in the
          month then a NODATA value should be used.

"31"      Data values for the 31st day of the month.  If there is no 31st day in the 
          month then a NODATA value should be used.


NODATA value = -9999.0 for floating point values (should have same number of decimals
                        as rest of data file
             = -9999    for integer values









Monthly Data


Filename:   varname.YYYY.txt

where:      varname is the name of the variable (standard names have not been discussed)
            YYYY    is the four digit year

example:    monthly_prcp.1999.txt  represents monthly precipitation data for year 1999.

File content:

line 1      YYYY free form comment which includes units
line 2      "CellID" "Lat" "Long" "01" "02" "03" "04" "05" "06" "07" "08" "09" "10" "11" "12"
line 3           (data lines here to end of file)
line 4                        ...
line 5                        ...
...                           ...
...                           ...
line 39927                    ...
line 39928                    ...


example file:  monthly_prcp.1999.txt

The first two lines are reserved for header information.  The first line should contain the year, 
followed by a short description of the data (inluding units!). Line two is header as described below.  
Surrounding each parameter in line two of the header with double quotes and a space would be most 
Lines 3-39928 contain the data. Having at least one space between 
each column is optimal.

RIMS members should record their data (eg., 12f8.1) to as many decimal places as needed.

All files should have 15 columns.


Line 1    Contains Two items:

YYYY      The year in four digits 

comment   This is a free form comment line for information deemed appropriate.
          Units are required here.



Line 2    Contains column names for the data

"CellID"  The EASE-GRID cell ID.

"Lat"     Latitude in the range 0-90 where 0 is the equator and 90 is the north pole.
          Decimal degrees with a minimum of 4 decimals is required.

"Long"    Longitude in the range 0-360 where Long = 0 is Greenwich and Long = 180
          is 180 degrees E or W.  To convert to -180 to 180 deg Longitude you can use the
	  following line of C code:

	  	if (Long > 180)
			Long = Long-360;

          Decimal degrees with a minimum of 4 decimals is required.

"01"      Data values for January.  In most cases these data will 
          be floating point with an appropriate number of decimal places.  Some data
          such as vegetation type or rain/no rain will be integer.

"02"      Data values for February

...

...

"12"      Data values for December.  


NODATA value = -9999.0 for floating point values (should have same number of decimals
                        as rest of data file
             = -9999    for integer values



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Richard Lammers