EGU2020-12918
https://doi.org/10.5194/egusphere-egu2020-12918
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

First airborne gravity wave observations at the world’s hotspot in Southern Argentina

Markus Rapp1,2, Bernd Kaifler1, Andreas Dörnbrack1, Sonja Gisinger1, Tyler Mixa1, Robert Reichert1, Natalie Kaifler1, Andreas Giez3, Peter Preusse4, Markus Geldenhuis4, Lukas Krasauskas4, Wolfgang Woiwode5, Felix Friedl-Vallon5, Alejandro de la Torre6, Jose Luis Hormaechea7, Martin Riese4, Björn-Martin Sinnhuber5, Peter Hoor8, and Andreas Engel9
Markus Rapp et al.
  • 1DLR (German Aerospace Center), Institute of Atmospheric Physics, Weßling, Germany (markus.rapp@dlr.de)
  • 2Meteorologisches Institut München, Ludwig-Maximilians-Universität München, Munich, Germany
  • 3Deutsches Zentrum für Luft- und Raumfahrt, Einrichtung Flugexperimente, Oberpfaffenhofen, Germany
  • 4Forschungszentrum Jülich, Institute of Energy- and Climate Research, Stratosphere (IEK-7), Jülich, Germany
  • 5Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research, Karlsruhe, Germany
  • 6Facultad de Ingeniería, Universidad Austral and CONICET, Buenos Aires, Argentina
  • 7Estacion Astronomica Rio Grande, Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata & CONICET, Argentina
  • 8Institute of Atmospheric Physics, Johannes Gutenberg-University of Mainz, Germany
  • 9Institute for Atmospheric and Environmental Sciences, Goethe University Frankfurt, Germany

The region around Southern Argentina and the Antarctic peninsula is known as the world’s strongest hotspot of stratospheric gravity wave activity. In this region, large tropospheric winds are perturbed by the orography of the Andes and the Antarctic peninsula resulting in the excitation of mountain waves which might propagate all the way up into the upper mesosphere when the polar night jet is intact. In addition, satellite observations also show large stratospheric wave activity in the region of the Drake passage, i.e., in between the Andes and the Antarctic peninsula, and along the corresponding latitudinal circle of 60°S. The origin of these waves is currently not entirely understood. Several hypotheses are currently being investigated, like for example the idea that the mountain waves that were originally excited over the Andes and the Antarctic peninsula propagate horizontally to 60°S and along the latitudinal circle. In order to investigate this and other hypotheses the German research aircraft HALO was deployed to Rio Grande, Tierra del Fuego, at the Southern Tip of Argentina in September and November 2019 in the frame of the SOUTHTRAC (Southern hemisphere Transport, Dynamics, and Chemistry) research mission. A total of 6 dedicated research flights with a typical length of 7000km were conducted to obtain gravity wave observations with the newly developed ALIMA (ALIMA=Airborne LIdar for Middle Atmosphere research)-instrument and the GLORIA (GLORIA=Gimballed Limb Observer for Radiance Imaging of the Atmosphere) limb sounder. While ALIMA measures temperatures and temperature perturbations in the altitude range from 20-90 km, GLORIA observations allow to characterize wave perturbations in temperatures and trace gas concentrations below flight level (<~14 km). This paper gives an overview of the mission objectives, the prevailing atmospheric conditions during the HALO deployment, and highlights some outstanding initial results of the gravity wave observations.

How to cite: Rapp, M., Kaifler, B., Dörnbrack, A., Gisinger, S., Mixa, T., Reichert, R., Kaifler, N., Giez, A., Preusse, P., Geldenhuis, M., Krasauskas, L., Woiwode, W., Friedl-Vallon, F., de la Torre, A., Hormaechea, J. L., Riese, M., Sinnhuber, B.-M., Hoor, P., and Engel, A.: First airborne gravity wave observations at the world’s hotspot in Southern Argentina, EGU General Assembly 2020, Online, 4–8 May 2020, https://doi.org/10.5194/egusphere-egu2020-12918, 2020

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Presentation version 1 – uploaded on 06 May 2020
  • CC1: Comment on EGU2020-12918, Paul Pukite, 15 May 2020

    Interesting that the region near the southern Andes is an origin of gravity wave momentum transfer for the earth, and showing strong annual and semi-annual impulses.

    Regarding the Drake Passage near the southern Andes, Woodworth and Hibbert (Ocean Science, vol. 14, no. 4, pp. 711–730, 2018) were able to extract the long-period tidal forcing from bottom-pressure readings. These long-period tides can then be used to calibrate the forcings used to drive ENSO and other climate dipole cycles. Crucially, impulses of an annual and semi-annual cycle are required to amplify the tidal cycles to generate the correct synchronizaton.  

    https://geoenergymath.com/2019/02/25/long-period-tides/