Carbon monoxide and total ozone in Arctic and Antarctic regions: seasonal variations, long-term trends and relationships

Total column abundances of carbon monoxide (CO) were measured in Zvenigorod, near Moscow, and in the Russian Arctic (from Severnaya Zemlya to Wrangel Island, including the drifting station in the central part of the Arctic Basin). CO was found to decrease from early spring to summer, both in central Russia and in the Arctic; absolute mean CO abundances in both regions differed little. Vertically averaged CO mixing ratios over Zvenigorod were compared with those measured in the surface layer at Point Barrow, Alaska, between July 1988 and December 1990. Good agreement between them was observed in summer; in winter and early spring, however, the CO mixing ratios for Barrow were 40% greater than for Zvenigorod. This difference is most likely explained by CO becoming concentrated under the Arctic inversion layer in winter. The mean tropospheric mixing ratio over Zvenigorod increased at a rate of 0.7 ± 0.2% year−1 during the period between 1970 and 1993. This increase was not steady; during 1970–1982 it was larger, ∼ 1.5% year−1. Long-term variations in both sources and sinks of CO could be responsible for these phenomena.