Journal cover Journal topic
Annales Geophysicae An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 1.621 IF 1.621
  • IF 5-year value: 1.614 IF 5-year
    1.614
  • CiteScore value: 1.61 CiteScore
    1.61
  • SNIP value: 0.900 SNIP 0.900
  • IPP value: 1.58 IPP 1.58
  • SJR value: 0.910 SJR 0.910
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 80 Scimago H
    index 80
  • h5-index value: 24 h5-index 24
Volume 33, issue 9
Ann. Geophys., 33, 1091-1096, 2015
https://doi.org/10.5194/angeo-33-1091-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Ann. Geophys., 33, 1091-1096, 2015
https://doi.org/10.5194/angeo-33-1091-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

ANGEO Communicates 10 Sep 2015

ANGEO Communicates | 10 Sep 2015

First experimental verification of summertime mesospheric momentum balance based on radar wind measurements at 69° N

M. Placke1, P. Hoffmann1, and M. Rapp2,3 M. Placke et al.
  • 1Leibniz Institute of Atmospheric Physics at the Rostock University, Kühlungsborn, Germany
  • 2Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany
  • 3Meteorologisches Institut München, Ludwig-Maximilians-Universität München, Munich, Germany

Abstract. Gravity waves (GWs) greatly influence the background state of the middle atmosphere by imposing their momentum on the mean flow upon breaking and by thus driving, e.g., the upper mesospheric summer zonal wind reversal. In this situation momentum is conserved by a balance between the vertical divergence of GW momentum flux (the so-called GW drag) and the Coriolis acceleration of the mean meridional wind. In this study, we present first quantitative mean annual cycles of these two balancing quantities from the medium frequency Doppler radar at the polar site Saura (SMF radar, 69° N, 16° E). Three-year means for 2009 through 2011 clearly show that the observed zonal momentum balance between 70 and 100 km with contributions from GWs only is fulfilled during summer when GW activity is strongest and more stable than in winter. During winter, the balance between GW drag and Coriolis acceleration of the mean meridional wind is not existent, which is likely due to the additional contribution from planetary waves, which are not considered by the present investigation. The differences in the momentum balance between summer and winter conditions are additionally clarified by 3-month mean vertical profiles for summer 2010 and winter 2010/2011.

Publications Copernicus
Download
Short summary
Imposed momentum from mesospheric breaking gravity waves (GWs) is conserved by a balance between vertical divergence of GW momentum flux and Coriolis acceleration of the mean meridional wind. We present the first experimental verification of the momentum balance from the Saura MF radar at 69°N. For contributions from GWs only this balance is fulfilled between 70 and 100km during summer when GWs dominate the mesospheric dynamics, but it does not exist in winter due to planetary wave impacts.
Imposed momentum from mesospheric breaking gravity waves (GWs) is conserved by a balance between...
Citation
Share