Intraseasonal interactions between the tropics and extratropics in the Southern Hemisphere

Observational evidence is presented of connections between tropical heating and circulation changes in subtropical and extratropical latitudes of the Southern Hemisphere (SH) in summer and winter, and the processes responsible for these interactions are described. The observational evidence suggests that, during SH summer (but not SH winter), both the acceleration of westerly winds south of the heating region through meridional overturnings and excitation of Rossby waves are possible. During winter, the enhanced tropical convective activity results again in local meridional overturning with zonal wind acceleration of Rossby waves farther south.