UDC 651.513: 551.506.1(73) WEATHER AND CIRCULATION OF OCTOBER 1971 Continued Cold in the West and Warm in the East

• Main Authors: Robert R. Dickson-national, Suitland Md
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: North Atlantic; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.395.3283; http://docs.lib.noaa.gov/rescue/mwr/100/mwr-100-01-0074.pdf

One of the striking features of the monthly mean circulation during October 1971 (figs. 1, 2) was the development of a vigorous polw vortex. This, together with a girclle of above-normal heights at midlatitudes, resulted in a hemispheric band of strong westerlies at upper midlatitudes. Relative to normal, it is apparent (fig. 3) that the greatest westerly wind increase mas from the mid-Atlantic across Asia to Alaska. Although there was little change bensee 1971) to October, increasing westerlies over the North Atlantic were associated with progression of the downstream European trough. Intensification of the latter circulation feature during October (fig. 3) was notable. Northern portions of this trough, embedded in the main band of the westerlies, progressed more rapidly than southern portions leading to a strong northeast-southwest tilt and accompanying northward momentum transport. Elsewhere over Asia, the strongly increasing westerlies were accompanied by progression leading to a mid-Asia ridge and Sea of Japan trough, and by the rapid decline in location of the Atlantic trough from September (Tau- of heights in northeast Asia (fig. 3).