2002 Annual

Wednesday, 16 January 2002: 4:15 PM
Stratospheric Mountain Waves: Observations and Modeling for a Proposed Sailplane that Will Use These Waves to Reach 100,000 Feet
Elizabeth J. Carter, Firnspiegel, LLC, Kings Beach, CA; and E. H. Teets Jr.
Poster PDF (1.2 MB)
A research project currently underway is phase one of an effort for a sailplane to use stratospheric mountain waves to reach an altitude of 100,000 feet. Once into the stratosphere, the waves propagate upward with increasing strength, generally maintaining a constant energy, defined as: air density x vertical-wind-component2. One characteristic of these waves is that this increasing vertical component of the wind is likely, at some altitude, to lead to instability and what is referred to as "overturning" and formation of large turbulent structures. Overturning originating from amplification has not been experienced by aircraft as yet, as far as in now known. The general impression of the stratosphere as a quiet region is not, in general justified.

Strong stratospheric mountain waves have been identified in data from northern Scandinavia and the south island of New Zealand. It has been determined that the first attempts to reach 100,000 feet in a sailplane will take place in New Zealand. Based on current aircraft limitations phase one is limited to 62,000 feet. An important key to understanding these waves is the polar vortex. It is known that these waves propagate into the middle and upper stratosphere when the outer region of the polar vortex lies above a strong tropospheric wind band, above mountainous terrain. However, the exact structure of the polar vortex in relation to the "good" wave cases found over the south island of New Zealand is not known

A few of the best wave events and a few of the events in which waves are extinguished at the tropopause have been analyzed in detail. This analysis involved investigating the atmospheric conditions (satellite, radar, and observational meteorological data) for each case. The best wave cases have been modeled using the Fifth Generation Penn State/NCAR (National Center for Atmospheric Research) Mesoscale Model (MM5). The model is being used to: (1) verify the strength, location, structure, and frequency of occurrence of strong mountain waves, (2) to verify the vertical size, location, and the strength of the assumed turbulence or overturning expected in the stratosphere, (3) to determine the structure of the polar vortex in the Southern Hemisphere and how it relates to the stratospheric mountain waves, and (4) for forecasting these stratospheric mountain waves in real-time for the field campaign to reach 100,000 feet using a sailplane.

Supplementary URL: http://www.firnspiegel.com/Perlan.html