This paper discusses observations of the total daytime stratospheric column abundance of NO2 made over the range in latitude from 40 ¿S to the North Pole. The equatorial abundance is less by a factor of 2 than at mid-latitude. A summer maximum in the northern hemisphere exists, and the amplitude of the seasonal variation increases from 2 at mid-latitude to over 6 at 65 ¿N. In winter, when there is not a warming in progress in the stratosphere and there is strong zonal flow, there is an abrupt drop in NO2 abundance near 50 ¿N. The decrease occurs over only a few degrees of latitude where the temperature near 30 km exhibits a poleward drop as well. During a warming, the cliff disappears as a result of rapid meridional transport of mid-latitude stratospheric air into the Arctic.