How to convert the rainfall unit of kg/m^2 to mm?

[GES DISC - ingridgs]

Answer:

The unit of kg/m^2 is equivalent to mm, as 1000 cm^3 of water has a mass of very nearly 1 kg at 4°C .

kg/m^2 ==> m*kg/m^3 ==> m*kg/(100cm)^3 ==> 1000*mm*kg/(1000*1000*cm^3) ==> 1000mm/1000 ==> mm

At any temperature other than 4 °C, the density of water is in fact lower (water is most dense at 4 °C). However, the change is very small at most temperatures, and so to a very close approximation, the mass of 1000 cm^3 of water is 1 kg at most temperatures. Therefore, the rainfall unit of kg/m^2, as a very close approximation at most temperature, is equivalent to unit of mm.