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Ann. Geophys., 24, 1159-1173, 2006
www.ann-geophys.net/24/1159/2006/
© European Geosciences Union 2006
The MaCWAVE program to study gravity wave influences on the polar mesosphere
R. A. Goldberg1, D. C. Fritts2, F. J. Schmidlin3, B. P. Williams2, C. L. Croskey4, J. D. Mitchell4, M. Friedrich5, J. M. Russell III6, U. Blum7, and K. H. Fricke8
1NASA/Goddard Space Flight Center, Code 612.3, Greenbelt, MD 20771, USA
2NorthWest Research Assoc., Colorado Research Associates Div., Boulder, CO 80301, USA
3NASA/Goddard Space Flight Center, Wallops Flight Facility, Code 972, Wallops Island, VA 23337, USA
4Pennsylvania State University, Department of Electrical Engineering, University Park, PA 16802, USA
5Graz University of Technology, A-8010 Graz, Austria
6Hampton University, Center for Atmospheric Research, Hampton, VA 23681, USA
7Forsvarets forskningsinstitutt, Postboks 25, NO-2027 Kjeller, Norway
8Physikalisches Institut der Universität Bonn, D-53115 Bonn, Germany
Abstract. MaCWAVE (Mountain and Convective Waves
Ascending VErtically) was a highly coordinated rocket,
ground-based, and satellite program designed to address gravity wave forcing
of the mesosphere and lower thermosphere (MLT). The MaCWAVE program was
conducted at the Norwegian Andøya Rocket Range (ARR, 69.3° N) in
July 2002, and continued at the Swedish Rocket Range (Esrange, 67.9° N) during
January 2003. Correlative instrumentation included the ALOMAR MF and MST
radars and RMR and Na lidars, Esrange MST and meteor radars and RMR lidar,
radiosondes, and TIMED (Thermosphere Ionosphere Mesosphere
Energetics and Dynamics) satellite measurements of thermal structures. The
data have been used to define both the mean fields and the wave field
structures and turbulence generation leading to forcing of the large-scale
flow. In summer, launch sequences coupled with ground-based measurements at
ARR addressed the forcing of the summer mesopause environment by anticipated
convective and shear generated gravity waves. These motions were measured
with two 12-h rocket sequences, each involving one Terrier-Orion payload
accompanied by a mix of MET rockets, all at ARR in Norway. The MET rockets
were used to define the temperature and wind structure of the stratosphere
and mesosphere. The Terrier-Orions were designed to measure small-scale
plasma fluctuations and turbulence that might be induced by wave breaking in
the mesosphere. For the summer series, three European MIDAS (Middle
Atmosphere Dynamics and Structure) rockets were also launched from ARR in
coordination with the MaCWAVE payloads. These were designed to measure
plasma and neutral turbulence within the MLT. The summer program exhibited a
number of indications of significant departures of the mean wind and
temperature structures from ``normal" polar summer conditions, including an
unusually warm mesopause and a slowing of the formation of polar mesospheric
summer echoes (PMSE) and noctilucent clouds (NLC). This was suggested to be
due to enhanced planetary wave activity in the Southern Hemisphere and a
surprising degree of inter-hemispheric coupling. The winter program was
designed to study the upward propagation and penetration of mountain waves
from northern Scandinavia into the MLT at a site favored for such
penetration. As the major response was expected to be downstream (east) of
Norway, these motions were measured with similar rocket sequences to those
used in the summer campaign, but this time at Esrange. However, a major
polar stratospheric warming just prior to the rocket launch window induced
small or reversed stratospheric zonal winds, which prevented mountain wave
penetration into the mesosphere. Instead, mountain waves encountered
critical levels at lower altitudes and the observed wave structure in the
mesosphere originated from other sources. For example, a large-amplitude
semidiurnal tide was observed in the mesosphere on 28 and 29 January, and
appears to have contributed to significant instability and small-scale
structures at higher altitudes. The resulting energy deposition was found to
be competitive with summertime values. Hence, our MaCWAVE measurements as a
whole are the first to characterize influences in the MLT region of
planetary wave activity and related stratospheric warmings during both winter
and summer.
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