Upper Mean Flow over the North Atlantic during January 1952

Abstract

Three mean atmospheric cross sections, one along the eastern coast of North America near longitude 80° West, one extending from Hudson's Bay out over the western Atlantic and the third along the western coasts of Europe and North Africa for January 1952 are presented. Four distinct currents are discussed in some detail; they are:

A. A polar stratospheric jet stream which is most clearly defined over Scandinavia where it shows up as a separate current centered near latitude 62° North. The maximum winds are above the 100-mb level.

B. A tropospheric jet stream in middle latitudes which weakens appreciably between the eastern coast of North America and western Europe but can be traced through all three cross sections (central potential temperature about 335° A).

C. A well-defined maximum over North Africa at latitude 24° North which has no clear connection with any maxima over North America and may form over the Atlantic Ocean. This current is centered at a potential temperature of approximately 345°

A. D. A mean low-latitude west-wind maximum over Panama at 45,000 feet near latitude 11° North. Mean observed wind profiles at Albrook Field, Panama and at Swan Island indicate that this really is a separate current and not the south edge of the middle-latitude jet stream. The central potential temperature in this maximum is about 355°