The Composite Analysis of Upper Level Ozone at Northern Middle Latitudes

This paper presents the trends and characteristics of upper ozone layers over middle latitudes by the analyses of the Umkehr data of the period of 1965~ 1993. The results, from 1965 to 1993, show that the upper ozone variation of middle latitudes per decade are about –1~2%, and the ozone seasonal variations between the layer of 28~36 km and the layer of above 36 km have opposite phases. Because of the eruption of El Chichon and Pinatubo, during the period of 1982~ 1983 and after 1991 there was a sudden change in upper layer.