Variations in the vertical distribution of atmospheric ozone during the passage of a short wave in the Westerlies

Abstract

Vertical distributions of ozone and of temperature taken from a series of balloon flights at Albuquerque, New Mexico, approximately every 4 hours over a -day period during which a short-wave upper trough passed over the station are studied together with synoptic meteorological data. The analysis indicates that with the approach of the trough and the simultaneous lowering of the tropopause and a southeastward displacement of the subtropical jet stream over the station, there is an increased influx of ozone-rich polar stratospheric air over the station in the form of thin layers, which replaces ozone-poor subtropical air. This results in a layer structure characterized by several maxima and minima in the vertical distribution of the partial pressure of ozone and by corresponding maxima and minima in the vertical distribution of the thermal stability as indicated by the temperature soundings. The layer structure is most pronounced between the lower tropopause and the 20-km level. The large-scale features of the layer structure, especially with regard to ozone, show a remarkable persistence from sounding to sounding throughout the entire period of observations, which indicates that the layers associated with the long-wave pressure system and the accompanying jet stream have a very large horizontal, or quasi-horizontal, extent. At the same time, variations in the vertical distribution of ozone with respect to time, observed as the short-wave trough is being displaced with respect to the station, indicate that within the layer structure, especially in, or near, a trough, there also may exist horizontal gradients of the partial pressure of ozone of considerable magnitude in the direction of the flow as well as in a transverse direction.