Title: The role of tropical and subtropical eddy moisture transports in the general circulation

Abstract: We investigate the seasonal cycle of meridional moisture (latent heat) transport in the tropics and subtropics by disturbances to the zonal mean. Stationary transport by planetary scale waves is found to be large in the subtropical lower troposphere and dominates the overall poleward transport during summer. In addition westward and eastward propagating sub-planetary scale waves dominate in the tropics and midlatitudes, respectively. The analysis reveals that the seamless eddy moisture transport from the deep tropics to the pole represents the transport by distinct dynamical features.

The statistical transformed Eulerian mean formulation is used to assess the role of eddy meridional moisture transport in the general circulation. Eddy moisture transport increases the total mass transport by a factor of 2 to 3 in the subtropics and midlatitudes. The impacts are largest during Northern Hemisphere summer highlighting the important role of moisture transport by subtropical anticyclones, tropical and baroclinic waves in the general circulation.

Host: Marty Singh
Faculty Host: Alan Plumb