A CASE STUDY OF CONFLUENCE AS RELATED TO THE JET STREAM

Abstract

This is the second report on a continuing project designed to investigate quantitatively the confluence process and associated changes in the strength and location of the mid-tropospheric jet stream. An empirical study has been made of a case of large-scale confluence as observed on a sequence of 5-day mean charts. It is found that the local change in wind speed is related to the relative advection of cold and warm air on either side of the jet axis and also to the advection of wind speed along the axis. Tentative estimates of vertical motion indicate sinking motion in the cold air north of the jet axis and rising motion in the warm air to the south.