The effect of aerosol on the infrared radiative cooling

The aerosol absorption is incorporated into the UU radiation model, studying the effects due to aerosol presence for different atmospheric profiles representing various latitudinal zones and seasons for both clear and cloudy conditions. The aerosol absorption and emission in the spectral range of 8-14 microns are parameterized using the broadband emissivity concept and neglecting the aerosol scattering effect. It is suggested that additional radiative cooling in the lower troposphere (below 3 km) will occur due to the presence of aerosols. In a clear tropical atmosphere with heavy haze 29 C/day cooling is present. It is found that although high cirrus cloud presence does not affect the aerosol cooling, the presence of other types of clouds makes the cooling effect negligible. Although the aerosol cooling effect is weaker for colder atmopsheres, it becomes important due to the simultaneous reduction in the infrared cooling rate.