ecCodes definition

Name:Total column waterAbbreviation:tcwUnit:W m-2 sparamId:136

S2S details

DefinitionVertical integral from the ground to the nominal top of the atmosphere expressing the total amount of water (vapour + cloud water + cloud ice), but no precipitation included.
ValidityDaily averaged
Comment Computed from instantaneous values at 00, 06, 12 and 18Z

WMO GRIB2 definition

Parameter
Discipline0Meteorological products
Parameter Category1Moisture
Parameter Number51
Total column water (Vertically integrated total water (vapour + cloud water/ice)
Level
Type of first fixed surface1Ground or water surface
Scale factor of first fixed surfaceall bits to 1Missing
Scaled value of first fixed surfaceall bits to 1Missing
Type of second fixed surface8
 Nominal top of the atmosphere
Scale factor of second fixed surfaceall bits to 1Missing
Scaled value of second fixed surfaceall bits to 1Missing