Liquid Water Path

Liquid water path (LWP) is the mass of cloud liquid water in a vertical atmospheric column per unit area, in grams per square meter, equal to the integral of cloud liquid water content over height. It controls cloud optical thickness, albedo, and the shortwave radiation reaching the sea surface, so it is central to the marine cloud radiative effect. Marine stratocumulus typically carry 50 to 200 g/m2. Passive microwave radiometers retrieve LWP over the ocean from brightness-temperature emission, and it pairs with precipitable water in cloud and precipitation studies and in evaluating the surface radiation budget.