2007 Workshop:Short Period Gravity Waves
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Contents |
Introduction
Short period gravity waves and their effects in the MLT region
This workshop will focus on short-period gravity waves (<30 min period) in the mesosphere and lower-thermosphere (MLT) at all latitudes, including new theoretical, numerical, and observational results. Short-period gravity waves comprise a significant fraction of wave energy at MLT heights. However, some challenges exist in the study of such short-period waves. Their excitation and propagation are strongly dependent on larger scale atmospheric structure, dynamics, and variability at all altitudes. Furthermore, their small scale size generally prohibits direct simulation in large-scale models, limiting our ability to study them numerically under realistic conditions. Due to these challenges, it is necessary to understand and quantify short-period gravity wave processes and effects in the MLT via observation and detailed numerical or theoretical modeling. It is also necessary to understand gravity wave interactions with observable atmospheric processes, an example being the modulation of nighttime airglow chemistry by gravity waves.
Talks will pertain broadly to short-period gravity waves in the MLT, and the techniques by which they are observed. Specific topics may include short-period gravity wave excitation, propagation, ducting, dissipation, breaking, and nonlinearity in the MLT. Gravity wave effects on chemistry, modulation of airglow layers, and transport/deposition of energy and momentum are also of particular interest.
The workshop is organized as a series of short talks, beginning with general overviews of the present state of research, and progressing to contributed short presentations of ~10 min. Talks will focus on new research and recently-published results, while maintaining a format which is friendly to a broad audience. Student contributions are welcome and encouraged. Additional discussion time of 30 minutes will be allotted following the talks. Anyone interested to contribute a talk, or to show a few slides during the discussion session, should contact Jonathan Snively by email (jbs231@psu.edu) as soon as convenient.
Chairs and Presenters
Chairs
Presenters
- D C Fritts "High-frequency gravity wave propagation and dissipation in the MLT"
- G R Swenson, F Vargas "Gravity waves and vertical wavelength from airglow phase"
- R L Walterscheid, M P Hickey, G Schubert, D Brinkman "Acoustic waves and acoustic wave processes in the lower thermosphere"
- R W Schunk, L Scherliess, J J Sojka, D C Thompson, L Zhu "A Thermosphere-Ionosphere-Plasmasphere data assimilation model
component for a seamless ocean-atmosphere model"
- Y Yu, M P Hickey "Ducted gravity waves simulated with their energy flux"
Time and Location
Monday, 13:00 - 15:00 in Zia
Presentation Materials and Final Report
Images, power point, pdf
Comments and Questions
- Wave breaking level By Liuhanli on Mon Jun 25, 2007 2:03 pm
If the wave is "breaking" at Richardson numbers much larger than 1/4, then we would expect that the wave would break at lower altitudes than that that deduced from linear saturation theory.
- Heat flux and Prandtl number By Liuhanli on Mon Jun 25, 2007 1:30 pm
What is the physical explanation for the heat flux to be small and Prandtl number to be large during wave breaking? And does the Prandtl number change with time over the couse of the wave breaking? Does this also mean that the transport of the constituents and thus the Prandtl number for the constituents diffusion is also small?
