Proceedings with Extended Abstracts (single PDF file) - Radio ...

VHF ATMOSPHERIC AND METEOR RADAR INSTALLATION ATDAVIS, ANTARCTICA: PRELIMINARY OBSERVATIONSR. J. Morris 1 , D. J. Murphy 1 , I. M. Reid 2 , and R. A. Vincent 21 Australian Antarctic Division, Kingston 7050, Tasmania, Australia2 University of Adelaide, Adelaide 5005, South Australia, AustraliaIntroductionA 55 MHz VHF atmospheric radar was commissioned at the high-latitude station Davis(78.0°E, 68.6°S geographic; 74.6°S magnetic), Antarctica during the austral summer of 2002-03. This paper presents an overview of this new facility which has been constructed for theAntarctic environment including, the 12 x 12 array of Yagi antennas, equipment module, andassociated infrastructure. Several aspects of the design tailored for the harsh Antarcticconditions are described. The radar specifications as developed by Atmospheric RadarSystems will be given together with an account of the proposed science to be conductedutilizing this new facility. The radar commenced 'spaced antenna' mode observation with 20kW of transmitted power from mid February 2003, and is scheduled to be upgraded to 120kW of transmitted power and a beam steering capability from November 2003. Some initialtroposphere and stratosphere region wind observations are presented. The facility includes ameteor radar capability and some preliminary mesosphere region results are also presented.Scientific ObjectivesVHF radars have been used extensively and successfully in the northern hemisphere to studythe dynamics of the Earth's polar atmosphere, however, with the exception of a short-termexperiment at South Georgia, they have not been used in the southern polar-regions. VHFradars allow the measurement of wind speeds in the troposphere and lower stratospherethroughout the year and in the mesosphere during daylight hours. They collect data with ahigh-time resolution (typically every few minutes) and with high-spatial resolution (typicalaltitude ranges of a few hundred metres) and operate stand alone with little operatorintervention. As a result, they have played a key role in developing our understanding of theenergy source regions in the lower atmosphere, energy deposition regions higher up, thecoupling between them and the resulting global circulation.The potential of the VHF radar can be demonstrated through consideration of the followingscientific objectives.Investigations of troposphere, stratosphere and mesosphere dynamics:• Gravity waves; climatology; case studies; propagation studies; and estimates ofmomentum flux in these atmospheric regions• Turbulence• MeteorologyStudies of Polar Mesospheric Summer Echoes (PMSEs):• Interhemispheric differences• Morphology and climatology• Links to noctilucent clouds• TheoryMeteor studies:• Mesosphere temperatures and winds411