The article examines how air moves between the stratosphere and troposphere in the Northern Hemisphere during winter. Different methods were used to calculate this movement, showing similar patterns but with varying amounts. Air mostly moves downwards from the stratosphere to the troposphere in certain latitude regions, influenced by Hadley cells. However, at higher latitudes, the movement is more unpredictable. The exchange between these layers does not directly affect higher altitudes. The composition of the stratosphere is mainly influenced by the exchange near the tropopause.