. . "Climate and Forecast (CF)" . . "tendency of air temperature due to longwave heating" . "The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. \"tendency_of_X\" means derivative of X with respect to time. \"longwave\" means longwave radiation. Air temperature is the bulk temperature of the air, not the surface (skin) temperature." . .