Tropospheric ozone: 2. Variations along a meridional band

Abstract

We present summaries of 703 previously unanalyzed ozonesonde launches at six stations distributed along a meridional band near 75øW between 9 ø and 53øN. Altitude and seasonal variations are examined to assist understanding the patterns and relative roles of injection, transport, loss, and synthesis of ozone in the middle troposphere. By comparison with other North American stations we conclude that a longitudinal gradient of 10-20% is likely, increasing eastward. The data are generally consistent with conventional understanding of tropospheric ozone in terms of increased injection from the stratosphere during spring at high latitudes, southward transport with molecular lifetimes of several months, and a principal sink at the ground, but details of the altitude and seasonal behavior can be interpreted ambiguously as evidence either for shorter-scale transport or for ozone synthesis within the troposphere. LONGITUDINAL VARIATIONSSince zonal circulations and mixing along the lines of latitude are, in general, more rapid and efficient than meridional circulations and mixing along the longitude circles, it is plausible to expect an approximate zonal symmetry for tropospheric ozone, providing that its lifetime in the troposphere is longer than or comparable to the zonal circulation time of about Paper number 7C0490. 5969

A model investigation of the impact of increases in anthropogenic NO x emissions between 1967 and 1980 on tropospheric ozone

“…Measurements of the latitudinal distribution of tropospheric ozone have been discussed by several investigators including Seiler and Fishman (1981), Logan et al (1981), Routhier et al (1980, Chatfield andHarrison (1977), Hilsenrath et al (1977) and Pruchniewicz (1973). Although there are considerable variations within these measurements at individual latitudes the observations consistently show that the concentrations of ozone in the troposphere exhibit a minimum in the tropics and increase with latitude in both hemispheres with maxima occurring poleward of "40 ° latitude.…”

Seasonal Variation of the Tropospheric Ozone : A Summer Minimum in Japan

“…An indication of the summer minimum has been found in the lower troposphere over Cape Kennedy (28.5*N) in North America according to the ozonesonde data analysed by Chatfield and Harrison (1977). The surface ozone observed at Poona (18*N) in India, Cape Grim (40.7*S) and Macquarie Is.…”

“…Some characteristic behaviors of the tropospheric ozone, with respect to diurnal, seasonal and latitudinal variations and temporal variations associated with day-to-day weather conditions, have been studied mainly by using the data from North America and Europe (e. g., Chatfield and Harrison, 1977;Fabian and Pruchniewicz, 1977;Singh et al, 1978;Oltmans, 1981).…”

Tropospheric Ozone

“…It has been used as an indicator of the origin of tropospheric 03 (Fabian et al 1968;Chatfield and Harrison, 1977;Liu et al 1980;. It has been used as an indicator of the origin of tropospheric 03 (Fabian et al 1968;Chatfield and Harrison, 1977;Liu et al 1980;.…”

“…In the tropics, the surface 03 values observed at Panama (Chatfield and Harrison, 1977), Natal and near Manaus (Kirchhoff, 1987; are about 15 ppbv in the days when there is no biomass burning. Observations made at three rural stations in Canada indicate that the daytime surface 03 mixing ratios in summer range from 25 to 35 ppbv .…”