Articles | Volume 24, issue 4
Ann. Geophys., 24, 1245–1255, 2006

Special issue: MaCWAVE

Ann. Geophys., 24, 1245–1255, 2006

  03 Jul 2006

03 Jul 2006

Polar mesosphere winter echoes during MaCWAVE

S. Kirkwood1, E. Belova1, U. Blum2,*, C. Croskey3, P. Dalin1, K.-H. Fricke2, R. A. Goldberg4, J. Manninen5, J. D. Mitchell3, and F. Schmidlin6 S. Kirkwood et al.
  • 1Swedish Institute of Space Physics, Box 812, 98128 Kiruna, Sweden
  • 2Physikalisches Institut der Universität Bonn, 53115 Bonn, Germany
  • 3EE Dept., Pennsylvania State University, University Park, PA 16802, USA
  • 4NASA/GSFC, Code 612.3, Greenbelt, MD20771, USA
  • 5Sodankylä Geophysical Observatory, T¨ahteläntie 62 FIN-99600 Sodankylä, Finland
  • 6Code 972, NASA/GSFC/Wallops Flight Facility, Wallops Is. VA 23337, USA
  • *now at: Forsvarets Forskningsinstitutt, N-2027 Kjeller, Norway

Abstract. During the MaCWAVE winter campaign in January 2003, layers of enhanced echo power known as PMWE (Polar Mesosphere Winter Echoes) were detected by the ESRAD 52 MHz radar on several occasions. The cause of these echoes is unclear and here we use observations by meteorological and sounding rockets and by lidar to test whether neutral turbulence or aerosol layers might be responsible. PMWE were detected within 30 min of meteorological rocket soundings (falling spheres) on 5 separate days. The observations from the meteorological rockets show that, in most cases, conditions likely to be associated with neutral atmospheric turbulence are not observed at the heights of the PMWE. Observations by instrumented sounding rockets confirm low levels of turbulence and indicate considerable small-scale structure in charge density profiles. Comparison of falling sphere and lidar data, on the other hand, show that any contribution of aerosol scatter to the lidar signal at PMWE heights is less than the detection threshold of about 10%.

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