The Role of Diabatic Heating in Ferrel Cell Dynamics

The Ferrel cell consists of the zonal mean vertical and meridional winds in the midlatitudes. The continuity of the Ferrel circulation and the zonal mean momentum and heat budgets imply a collocation of the eddy-driven jet and poleward eddy heat flux maxima, under certain assumptions, including the negligibility of diabatic heating. The latter assumption is questioned, since midlatitude storms are associated with latent heating in the midtroposphere. In this study, the heat budget of the Ferrel cell in both hemispheres is examined, using the JRA55 reanalysis data set. The diabatic heating rate is significant close to the center of the Ferrel cell during winter and at the ascending branch during summer in both hemispheres. The interannual variability shows a positive correlation between the diabatic heating rate in the midlatitude midtroposphere and the latitudinal separation between the eddy heat flux and the eddy-driven jet maxima during winter in both hemispheres.