ON THE ROLE OF THE SUBTROPICAL JET STREAM OF WINTER IN THE ATMOSPHERIC GENERAL CIRCULATION

Abstract

Calculations of budgets of heat, angular momentum and kinetic energy for the tropical latitudes are obtained in a coordinate system following the subtropical jet stream axis at the 200-mb surface. Comparisons of the fluxes of various quantities with those required at certain latitudes show that the vertical mass circulation has a very important role in the tropics and that the daily eddies are important on the poleward side of the jet stream. Large fluxes of various atmospheric properties are computed for 3 different months. The month of January, 1956, shows very large export of kinetic energy and angular momentum from tropics into middle latitudes. Statistics of the middle-latitude zonal and meridional motion are studied. It is shown that the month of January, 1956, was one of very low zonal index, blocking, and very slow eastward wave motion. Possible connection between lower and higher latitude circulations is suggested.