Changes in the distribution of the climate gases water vapor and ozone, in the upper troposphere and lower stratosphere (UTLS) have a strong impact on its radiation budget and on surface temperatures. Their distribution in the UTLS is governed by transport and mixing, which can be modulated by gravity waves. Therefore, understanding the role of gravity waves in modifying the distribution of climate relevant species in the UTLS is of crucial importance for the assessment of UTLS climate sensitivity. To this end, the Deep Propagating Gravity Wave Experiment DEEPWAVE aimed at a thorough investigation of (orographic) gravity waves and their propagation to high altitudes using multiple platforms. We present in-situ measurements of water vapor and ozone on the DLR Falcon research aircraft to study transport of these trace species in the upper troposphere and across the tropopause induced by mountain waves over the New Zealand Alps. Due to the strong gradient of H2O in the troposphere and of O3 in the stratosphere, these two trace gases are ideally suited to investigate trace gas transport by gravity waves.

Here, we focus our analysis on a strong mountain wave event with a wave breaking region in the stratosphere detected on 04 July 2014. Wavelet analyses show a strong upward directed water vapor flux in the upper troposphere and across the tropopause in the lower stratosphere correlated with high energy and momentum fluxes. The stratospheric ozone data confirm vertical transport of the trace species across the tropopause. Irreversible transport may be caused by wave-breaking spots between 15 and 25 km altitude. The comparison of in-situ measurements with results from high resolution Weather Research and Forecasting Model simulations allows to better understand the role of gravity waves for transport and mixing of trace species across the tropopause in the climate sensitive extratropical UTLS region.

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*email: Romy.Schlage@dlr.de
*Preference: Oral