Updated: 02 Dec 2019

5.1.7.  VAR_UNITS

The variable attribute VAR_UNITS specifies the actualunits in which the variable data are reported in the current data file. The allowed units are  case sensitivecombinations of unit prefixes and units given in Tables  7.4 and 7.5. The unit definitions are compliant to the Unidata  UDUNITS package [13]and have been extended by GEOMS aliases where appropriate (cf. Table 7.5). The prefix of a unit is concatenated with the unit, multiple units (multiplicative) are separated by spaces. Powers of units (integer) are concatenated with the unit; for example centimeter squared becomes cm2.

For example, if the total column of NO2 is equal to 2.7×10^15 molecules per square centimeter, then you can report it either as: 

2.7 with VAR_UNITS = Pmolec cm­2

or 2.7E15 with VAR_UNITS = molec cm­2

String data types must have a corresponding attribute value of an empty string:


VAR_UNITS = [empty]

Dimensionless variables which do not report a unit must have an attribute value of 1, e.g.:





Entry: single field, case sensitive

Format: Combination of entries in Tables 7.4and 7.5(brackets cannot be used)

Example 1: VAR_UNITS = mPa

Example 2: VAR_UNITS = Pmolec cm­2

Example 3: VAR_UNITS = molec cm­2