Arctic Ozone Oscillation

This figure is a correlation map between the spring (MAM) model ozone and the winter (JFM) AO index between 1980 and 2001. The regions where the correlation is statistically significant at the 99% level are located inside (deeper blues and brighter reds) the zones delimited by the thick black line. The white circles indicate the location of the stations used in the ozonesondes analysis. First graphic is for 500 hPa; second graphic is for 800 hPa.

Abstract

This study identifies the Arctic Oscillation (AO) signature on the interannual variability of tropospheric ozone, with an emphasis on spring ozone over the North American and European continents. The analysis is first performed on ozonesonde data. It is shown that the variability in AO explains up to 50% of the tropospheric ozone variability in the lower troposphere over North America during the spring months. Chemistry-transport model simulations in which the meteorology varies from year to year, but the emissions and net stratospheric production of ozone remain the same show similar results. The model results indicate the role of the AO in modulating stratosphere-troposphere exchange and in regulating the transport of ozone and its precursors from North America, Europe and Asia.

Reference: Lamarque, Jean-Francois and Peter G Hess, Arctic Oscillation modulation of the Northern Hemisphere spring tropospheric ozone, Geophys. Res. Lett., 31, L06127, doi:10.1029/2003GL019116, 2004. (AGU site)