MONTHLY MEAN VALUES AND SPATIAL DISTRIBUTION OF MERIDIONAL TRANSPORT OF SENSIBLE HEAT

Abstract

Monthly mean values of meridional transport of sensible heat by the atmosphere in the layer 850-500 mb. over the Northern Hemisphere poleward from the subtropics are analyzed for a period of 3½ years. The latitudinal values of this transport exhibit an annual cycle which is characterized by a rapid buildup from August to November and a slightly less rapid decline from February to June. Dissimilarities among the transport patterns for the same calendar months in different years are generally small; however, the month of December has marked variability. The longitudinal makeup of heat transport across latitude 45° N. in the cold season is dominated by three contributing regions which are associated with two of the three major waves observed in monthly mean flow patterns. The most sharply defined region of contribution to the heat transport across latitude 45° N. is associated with cold air moving southward to the rear of the trough line along the east coast of Asia. At 60° N., however, pronounced heat transport zones are generally absent except for the occasional appearance of a maximum over the eastern Atlantic and western Europe.