Abstract
A method of estimation for the infrared radiative fluxes in the cloudy atmosphere is presented. The upward, downward and net infrared radiative fluxes at the ground and in the atmosphere are expressed as the linear functions of “ apparent ” fractional cloudiness of low, middle and high clouds except for the cases of upward and net fluxes at a level above the height of high cloud. At the level there are some deviations of upward and net fluxes from the linear function of “ apparent ” fractional cloudiness owing to the non-blackness of the high cloud.
The net flux of infraredradiation at the ground obtained agrees with some empirical formulas, which are expressed by a linear function of “ apparent ” fractional cloudiness of low, middle and high clouds, obtained by Russian authors in functional form and numerical figures of coefficients.
The flux of outgoing infrared radiation (the cooling rate of the earthatmosphere system) decreases with the increase of cloudiness in the case of a sky covered with a single layer of any type of cloud. On the other hand, the atmospheric infrared radiative balance (the cooling rate of the atmosphere alone) decreases with the increase of cloudiness in the case of a sky covered with a single layer of high cloud but increases with the increase of cloudiness in the case of a sky covered with a single layer of middle or low cloud.
There is a relation between computed atmospheric infrared radiation balances and computed fluxes of outgoing infrared radiation. The relation is expressed by a linear regression equation with a high correlation coefficient in the case of overcast sky. The computed regression relations agree with those obtained by several authors from observations.
