The role of downward long-wave radiation in water vapor feedback and climate change

The character of the global-mean surface radiation balance as derived from various sources of global data will be reviewed including sources drawn from A-Train observations. The downward longwave radiation (DLR) component of this balance will be examined in some detail and its dependence on water vapor, temperature and lapse rate and cloudiness will be assessed. This background provides the basis for understanding the essential role of the DLR to the water vapor feedback and projected warming. The influence of this feedback on the global hydrological cycle will be addressed and it will be argued that certain aspects of the change in global precipitation with warming are in fact predictable consequences of this feedback and the changes to DLR associated with it.