Thermodynamic correlations between the sea surface temperature, water vapor content, and cloud fraction, using MODIS data

NASA MODIS data have been analyzed to quantify the relationship between the sea surface temperature (SST), water vapor content (WV), and cloud fraction (CF) for the time period from January 2000 to March 2017. SST and WV follow a Clausius–Claperyon type of a relationship with modified constants up to 300 K. However, beyond SST of 300 K, an alternate function prescribes the SST-WV correlation. A functional correlation between WV and CF has also been found for a limited range of CF, by introducing the atmospheric temperature at pressure altitude of 650 mbar as an additional parameter. The latter parameter is considered to be a modifier for the condensation process for WV to CF. An alternate correlation between SST, WV, and CF is found, where an inverted CF data tracks with WV up to SST of 300 K, and then becomes anti-correlated. These functional relationships can be used in global thermodynamic model or analyses of the Earth climate system, and also validate sub-models used in complex numerical approaches such as regional or global circulation models.