  New results from the Coupled Model Inter-comparison Project phase 5 (CMIP5)
and multiple global reanalysis datasets are used to investigate the
relationship between the mean and standard deviation in the surface air
temperature. A combination of a land-sea mask and orographic filter were used
to investigate the geographic region with the strongest correlation and in all
cases this was found to be for low-lying over-land locations. This result is
consistent with the expectation that differences in the effective heat capacity
of the atmosphere are an important factor in determining the surface air
temperature response to forcing.
