Transition from geostrophic turbulence to inertia–gravity waves in the atmospheric energy spectrum
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Callies-2014-Transition from geos.pdf
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Author(s)
Ferrari, Raffaele
Callies, Joern
Buhler, Oliver
Date Issued
December 2014
Journal
Proceedings of the National Academy of Sciences
Publisher
National Academy of Sciences (U.S.)
Citation
Callies, Jorn, Raffaele Ferrari, and Oliver Buhler. “Transition from Geostrophic Turbulence to Inertia–gravity Waves in the Atmospheric Energy Spectrum.” Proceedings of the National Academy of Sciences 111, no. 48 (November 17, 2014): 17033–17038.
Version
Final published version
Abstract
Midlatitude fluctuations of the atmospheric winds on scales of thousands of kilometers, the most energetic of such fluctuations, are strongly constrained by the Earth’s rotation and the atmosphere’s stratification. As a result of these constraints, the flow is quasi-2D and energy is trapped at large scales—nonlinear turbulent interactions transfer energy to larger scales, but not to smaller scales. Aircraft observations of wind and temperature near the tropopause indicate that fluctuations at horizontal scales smaller than about 500 km are more energetic than expected from these quasi-2D dynamics. We present an analysis of the observations that indicates that these smaller-scale motions are due to approximately linear inertia–gravity waves, contrary to recent claims that these scales are strongly turbulent. Specifically, the aircraft velocity and temperature measurements are separated into two components: one due to the quasi-2D dynamics and one due to linear inertia–gravity waves. Quasi-2D dynamics dominate at scales larger than 500 km; inertia–gravity waves dominate at scales smaller than 500 km.
MIT Department
Joint Program in Chemical Oceanography
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Woods Hole Oceanographic Institution
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1073/pnas.1410772111
