Analysis of satellite measurements of ozone, nitrous oxide and methane: intra-annual variations in the stratosphere

Abstract

Peculiarities in the intra-annual variations of 03, N20 and CH4 in the middle and upper stratosphere are analysed by different methods for the middle and polar latitudes of the Northern and the Southern hemispheres. In the middle stratosphere the phase of the O, annual harmonic shifts in the Northern Hemisphere from polar to lower latitudes, while in the Southern Hemisphere the downward shift is exhibited. The phase of the NiO annual harmonic shifts to the poles both in the Northern and Southern hemispheres, but in the Northern Hemisphere it is almost vertical with the horizontal spreading, while in the Southern Hemisphere the phase propagation has a remarkable downward component. The most similar shifts of the phase of the annual harmonic in the middle stratosphere of both hemispheres are exhibited for the CII” content in the middle and high latitudes. Remarkable differences are noted between the intervals with the increase of mixing ratios in the annual cycle at different latitudinal belts. In particular, these intervals are large in subtropical stratosphere, with a shorter and steeper decrease of the mixing ratios. The general decrease of these intervals is exhibited from middle to polar latitudes. The striking difference in temporal variations of the species exists between the northern polar and middle latitudes, where the month-to-month changes of the species are often opposite each to other. These peculiarities and interhemispheric differences are associated with the different stratospheric dynamics of the Northern and Southern hemispheres, particularly with different regimes of planetary wave activity in the northern and southern extratropical latitudes.