liquid water path

Liquid water path - in units of g/m2 is a measure of the total amount of liquid water present between two points in the atmosphere. LWP is an important quantity in understanding radiative transfer in the atmosphere. It is defined as the integral of liquid water content between two points in the atmosphere. For nadir observations and whole atmospheric column we have where is the liquid water mixing ratio and is the density of air (including water loading). The atmosphere is in approximate hydrostatic equilibrium and hydrostatic equation for atmospheric pressure is given by which gives