Simultaneous rocket and MST radar observation of an internal gravity wave breaking in the mesosphere
Document ID: 273
Smith, Steven A.1
Fritts, David C.1
Balsley, Ben B.2
Philbrick, C. Russell3
1 University of Alaska, Fairbanks, AK, U.S.A.
2 National Oceanic and Atmospheric Administration, Boulder, CO, U.S.A.
3 USAF, Geophysics Laboratory, Hanscom AFB, Bedford, MA, U.S.A.
Abstract
In June, 1983, the Structure and Atmospheric Turbulence Environment (STATE) rocket and Poker Flat Mesophere-Stratosphere-Troposphere radar campaign was conducted to measure the interaction between turbulence, electron density and electron density gradient that has produced unusually strong MST radar echoes from the summer mesosphere over Poker Flat, Alaska. Analysis or radar wind measurements and a concurrent wind and temperature profile obtained from a rocket probe carrying a three-axis accelerometer are given. The two data sets provide a fairly complete (and in some cases, redundant) picture of the breaking (or more correctly, the saturation) of a large-amplitude, low-frequency, long-wavelength internal gravity wave. The data show that small-scale turbulence and small-scale wave intensity is greatest at those altitudes where the large-scale wave-induced temperature lapse rate is most negative or most nearly unstable, but the wind shear due to the large-scale wave is a minimum. A brief review of linear gravity-wave theory is presented as an aid to the identification of the gravity-wave signature in the radar and rocket data. Analysis of the time and height cross sections of wind speed and turbulence intensity observed by the Poker Flat MST radar follows. Then, the vertical profile of temperature and winds measured by a rocket probe examined. Finally, the use of the independent data sets provided by the rocket and the radar are discussed and implications for theories of wave saturation are presented.
Keywords: atmospheric turbulence, electron density, gravity waves, meteorological radar, middle atmosphere, sounding rockets, temperature profiles, wave propagation, wind velocity measurement, acceleration, Alaska, amplitudes, wind shear
| Citation: | "Simultaneous rocket and MST radar observation of an internal gravity wave breaking in the mesosphere", Smith, S. A., D. C. Fritts, B. B. Balsley, C. R. Philbrick, International Council of Scientific Unions, Middle Atmosphere Program. Handbook for MAP, Vol. 20, NASA, June 1986, pp. 136 - 146, SEE N87-10419 01-42 |