Virtual Temperature

(of humid air), the temperature of dry air at which its density is equal to the density of the humid air being studied at the same pressure. In problems of atmospheric statics, the actual air is replaced by dry air of the same density by using the virtual temperature, which simplifies barometric formulas. The virtual temperature is higher than the true temperature; it is determined in degrees of an absolute scale by the formula T_v = T(l 0.605s), where T is the true temperature and s is the specific humidity. The use of virtual temperature is meaningful in cases when the air contains a high percentage of moisture. Virtual temperature can be considered to be equal to real temperature when it is below 0° C or when the relative humidity is low.