HR: 0800h
AN: SA31A-0336    [Abstracts]
TI: A new approach to the measurements of ion-neutral coupling in auroral thermospheric dynamics
AU: * Meriwether, J W
EM: john.meriwether@ces.clemson.edu
AF: Clemson University, Department of Physics and Astronomy 208 Kinard Laboratory, Clemson, SC 29634-0978 United States
AU: Larsen, M F
EM: mlarsen@clemson.edu
AF: Clemson University, Department of Physics and Astronomy 208 Kinard Laboratory, Clemson, SC 29634-0978 United States
AB: Aeronomic research in recent years has found the auroral thermosphere to be a highly dynamic environment, especially during active substorm periods. The rapidly-changing convective flow of ionospheric plasma coupled with Joule heating and localized conductivity enhancements caused by particle precipitation have strong effects upon the thermospheric wind and temperature fields. New Fabry-Perot technology has a great potential of addressing successfully questions regarding ion-neutral coupling, an extremely important issue in polar aeronomy. A technique featuring the common-volume approach to 630-nm Doppler shift FPI measurements with a network of three Fabry-Perot interferometers is the only remote-sensing means by which the three components of the thermospheric neutral wind vector can be determined independently within the small horizontal scale of ~50-75 km. The construction and deployment of three miniaturized narrow-field imaging Fabry-Perot interferometers (FPI) optimized for the measurements of Doppler shifts and Doppler broadening at 630 nm would provide an accuracy of ~2-3 ms-1 and ~10 K for 100 second exposure to 200 R of auroral 630-nm emission. This FPI network would provide vital information regarding the thermospheric neutral wind vector in common volume cells that are necessary to the accurate calculations of the development of Joule heating and Lorentz forcing in auroral substorm events. This approach overcomes the difficulty of measuring the thermospheric neutral wind vector for a region where vertical winds may be large (~50 m/s) and highly varying over short time scales of minutes and hours. These results can be applied to calculate accurately the vorticity and divergence of the thermospheric neutral wind flow to study the climatology of these parameters for quiet and active times. Such results would examine the process of geostropic adjustment that occurs as convective plasma acceleration takes place in auroral substorm events. Coordinated AMISR/FPI observations of auroral arcs would make possible the analysis of the response of the auroral thermosphere to plasma convective forcing producing significant neutral wind structures by ion-drag and Joule heating functions. Such measurements can be analyzed in real time and the data products of line-of-sight wind and temperature provided to any prospective user as required for real-time study of the ion-neutral coupling.
DE: 0310 Airglow and aurora
DE: 0358 Thermosphere: energy deposition (3369)
DE: 3369 Thermospheric dynamics (0358)
DE: 3384 Acoustic-gravity waves
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005