1Norwegian University of Science and Technology, Trondheim, Norway
2Chalmers University of Technology, Göteborg, Sweden
3Stockholm University, Stockholm, Sweden
4University of Cantabria, Santander, Spain
Received: 20 Aug 2010 – Discussion started: 11 Oct 2010
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.
Revised: 22 Dec 2010 – Accepted: 23 Dec 2010 – Published: 17 Jan 2011
Espy, P. J., Ochoa Fernández, S., Forkman, P., Murtagh, D., and Stegman, J.: The role of the QBO in the inter-hemispheric coupling of summer mesospheric temperatures, Atmos. Chem. Phys., 11, 495-502, doi:10.5194/acp-11-495-2011, 2011.