On the kinetic and thermal fluctuations of gravity waves in the strato- and mesosphere as observed by Doppler lidar
Abstract
The observation of wind and temperature in the stratosphere and mesosphere is crucial for understanding the dynamics in the middle atmosphere. Especially wind measurements are a challenging task. Only very few methods are capable to derive winds and temperatures in the entire stratosphere and mesosphere with vertical and temporal resolutions reasonable for gravity-wave studies. The Doppler Rayleigh/Mie/Raman lidar at the ALOMAR research station located in Northern Norway (69N, 16E) is capable to observe very variably dynamical situations at the edge of the polar vortex. The observations are performed even under sunlit conditions, which is essential for measuring atmospheric perturbations over several days and during summer at this location. We will present evidence for persistent inertia gravity wave signatures in horizontal wind and temperature and also show that they repeatedly occur as observed in the winters from 2012 to 2015. The measurements are of high quality from 20 km to about 80 km altitude during night and up to about 70 km during daytime. Both the kinetic and potential gravity-wave energy density can be derived and yield information about ensemble mean properties of gravity waves. We will present results from our analysis ranging from 5 minute temporal and 150 m vertical resolution and show that strong vertical and horizontal gradients are frequently observed. Such gradients challenge our understanding of wave propagation to the upper atmosphere and give rise to study wave-wave interactions in the winter stratopause region.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMSA31C..06B
- Keywords:
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- 3334 Middle atmosphere dynamics;
- ATMOSPHERIC PROCESSESDE: 3369 Thermospheric dynamics;
- ATMOSPHERIC PROCESSESDE: 3384 Acoustic-gravity waves;
- ATMOSPHERIC PROCESSESDE: 4490 Turbulence;
- NONLINEAR GEOPHYSICS