Articles | Volume 11, issue 2
Atmos. Chem. Phys., 11, 495–502, 2011
Atmos. Chem. Phys., 11, 495–502, 2011

Research article 17 Jan 2011

Research article | 17 Jan 2011

The role of the QBO in the inter-hemispheric coupling of summer mesospheric temperatures

P. J. Espy1, S. Ochoa Fernández1,4, P. Forkman2, D. Murtagh2, and J. Stegman3 P. J. Espy et al.
  • 1Norwegian University of Science and Technology, Trondheim, Norway
  • 2Chalmers University of Technology, Göteborg, Sweden
  • 3Stockholm University, Stockholm, Sweden
  • 4University of Cantabria, Santander, Spain

Abstract. Inter-hemispheric coupling between the polar summer mesosphere and planetary-wave activity in the extra-tropical winter stratosphere has recently been inferred using Polar Mesospheric Cloud (PMC) properties as a proxy for mesospheric temperature (Karlsson et al., 2007). Here we confirm these results using a ten-year time series of July mesospheric temperatures near 60° N derived from the hydroxyl (OH) nightglow. In addition, we show that the time-lagged correlation between these summer mesospheric temperatures and the ECMWF winter stratospheric temperatures displays a strong Quasi-Biennial Oscillation (QBO). The sign and phase of the correlation is consistent with the QBO modulation of the extra-tropical stratospheric dynamics in the Southern Hemisphere via the Holton-Tan mechanism (Holton and Tan, 1980). This lends strength to the identification of synoptic and planetary waves as the driver of the inter-hemispheric coupling, and results in a strong QBO modulation of the polar summer mesospheric temperatures.

Final-revised paper