Mountain wave excitation under extreme forcing conditions and propagation into the middle atmosphere

Benedikt Ehard* and Bernd Kaifler, Natalie Kaifler, Andreas Dörnbrack, Sonja Gisinger, Johannes Wagner, Markus Rapp
Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany

In this study we analyze Rayleigh lidar measurements conducted over New Zealand during the Deepwave campaign in 2014. We focus on the case with the largest stratospheric gravity wave response during the campaign which took place around 1st of August.

We characterize the meteorological condition with the help of ECMWF analyses. The propagation of the excited mountain waves from the troposphere into the middle atmosphere is investigated in detail by analyzing ground based lidar measurements, radiosonde measurements and mesoscale simulations.

The presented case is characterized by an intense cross mountain flow over the Southern Alps of New Zealand, which excited large amplitude mountain waves. The presence of both the polar jet and the subtropical jet provided a unique meteorological condition which allowed for an almost unhindered propagation of the mountain waves into the stratosphere. In the upper stratosphere wave breaking was observed.


*email: benedikt.ehard@dlr.de
*Preference: Oral