The correlation between temperature Gradient and Eddy heat flux in the Northern and Southern hemispheres

Abstract

The relationship between eddy heat flux and temperature gradient is studied. Correlations between the vertically-integrated total eddy heat flux and the temperature gradient are calculated for both the hemispheres using NCEP/NCAR reanalysis data. The results showed that, differently from the Northern Hemisphere (NH), in the Southern Hemisphere (SH) there is a large difference whether the vertically-integrated eddy heat flux is correlated with the temperature gradient at 1000 hPa, or with the vertically-integrated temperature gradient. The correlations are high and positive in both cases in the NH, as noted in earlier studies. However, in the SH when the vertically-integrated total eddy heat flux is correlated with the temperature gradient at 1000 hPa, there is a region in the middle latitudes where the correlations are highly negative. When the vertically-integrated temperature gradient is used, rather than the temperature gradient at 1000 hPa, the correlations are positive in both hemispheres. This indicates that it is necessary to use vertically-integrated temperature for obtaining the relation between eddy heat flux and temperature gradient in the case of the SH.