Seasonal and regional diurnal variations of cloud effects on atmospheric profiles of radiative heating/cooling from ISCCP-FD product
To explore the cloud effects (CE) on the radiative heating/cooling rate (HC) profiles in the atmosphere from ISCCP-FD, we use its 2009 3-hrly radiative profile flux subset (`PRF') to produce the seasonally-regionally averaged HCCE at eight local solar hours for the seven latitudinal zones, from Tropics to Polar regions. Clouds introduce an additional SW absorber to clear sky and essentially move more solar absorption upward that generates positive (negative) HCCE for the upper (lower) atmosphere with distinctive sign-changing levels, mostly at ∼440 and ∼680 hPa over most of time and with a strong diurnal variation. Clouds also move LW emission upward that causes less (more) emission in lower (upper) atmosphere and makes HCCE appear as a heating (cooling) as opposed to the SW HCCE with a reversed diurnal variation. Large LW heating mostly appears around midnight in the lower atmospheric layers with also distinctive heating/cooling sign-changing levels similar to SW but in an opposite sense. The total HCCE over the tropics acts to enhance the Hadley circulation while the seasonal variations are generally larger at higher latitude over land areas. Therefore, HCCE modulates the distribution of the atmospheric heating and cooling rates. The details of the radiative energy and forcing both vertically and diurnally need more systematic studies.