Zvenigorod carbon monoxide total column time series: 27 yr of measurements

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1998
• Subjects: ice core
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.523.9818; http://userpages.umbc.edu/~yurganov/Yurg_Chem.pdf

Importance of this Paper: Is the oxidizing capacity of the atmosphere, which is controlled mainly by hydroxyl, stable or not? Tropospheric OH is the main sink for carbon monoxide. Here is one of the longest consistent series of CO mea-surements in the total atmospheric column. After a period of increase total column amount of CO stabilized. We compared our data to available data on total ozone and stratospheric aerosol, which influence tropospheric OH. We concluded that the apparent CO stabilization after 1983 seems to be a result of growth both in its source and sink – OH concentration. The analysis of total column spectroscopic CO (carbon monoxide) observations over Russia between 1970 and 1996 revealed an upward trend, with a rate of 0.96 ppb/yr or 0.9%/yr. A similar trend has been reported over Switzerland between 1950 and 1987. This rate of CO growth is almost three times higher than the rate between 1920 and 1950, obtained from ice core data. However, after 1982, CO above Zvenigorod varied from year-to-year with no apparent long-term trend. The inter-annual variations in the data set were associated with vast forest and peat fires in the central Russia in 1972 and major volcanic eruptions after 1982. It was proposed, that the slowing down of the CO increase was caused mainly by changes in CO consumption by OH. Sensitivities of CO mixing ratio in the troposphere to changes in total ozone and stratospheric aerosol have been assessed from the smoothed monthly measurements. Corrections due to unstable aerosol and total ozone were introduced into the experimental data. The CO trend over the entire measure-ment period which would be expected under conditions of constant ‘‘undisturbed’ ’ total ozone and no stratospheric aerosol would be 1.3 ppb/yr, or 30 % higher, than the observed trend. A positive trend in OH concentrations between