HR: 09:40h
AN: SA11B-07    [Abstracts]
TI: Plasma Structuring at Mid-Latitudes during Super-Storms and their Impact on GPS-Based Navigation Systems
AU: * Basu, S
EM: sbasu@bu.edu
AF: Center for Space Physics Boston University, 725 Commonwealth Avenue , Boston, MA 02215 United States
AU: Basu, S
EM: santimay@aol.com
AF: Air Force Research Laboratory, 29 Randolph Road , Hanscom AFB, MA 01731
AU: Makela, J
EM: jmakela@uiuc.edu
AF: University of Illinois, 316 CSL, Urbana, IL 61801 United States
AU: Wright, J
EM: bill.wright@noaa.gov
AF: University of Colorado, NOAA, Boulder, CO 80309 United States
AU: Sheehan, R
EM: sheehanp@bc.edu
AF: Boston College, Institute for Scientific Research, Newton Center, MA 02467 United States
AU: MacKenzie, E
EM: eileen.mackenzie@hanscom.af.mil
AF: Boston College, Institute for Scientific Research, Newton Center, MA 02467 United States
AU: Coster, A
EM: acoster@haystack.mit.edu
AF: MIT Haystack Observatory, Route 40, Westford, MA 01886 United States
AU: Doherty, P
EM: dohertpd@bc.edu
AF: Boston College, Institute for Scientific Research, Newton Center, MA 02467 United States
AU: Rich, F
EM: Frederick.Rich@hanscom.af.mil
AF: Air Force Research Laboratory, 29 Randolph Road , Hanscom AFB, MA 01731
AU: Keskinen, M
EM: keskinen@ppd.nrl.navy.mil
AF: Naval Research Laboratory, 4555 Overlook Avenue, S.W., Washington, DC 20375 United States
AU: Chua, D
EM: dchua@ppd.nrl.navy.mil
AF: Naval Research Laboratory, 4555 Overlook Avenue, S.W., Washington, DC 20375 United States
AB: Two components of ionospheric plasma structuring at mid-latitudes during large magnetic storms have recently been documented (Basu, Su. et al., GRL, 2005). One component is found to be associated with the Storm Enhanced Density (SED) plumes, which have been shown to be ionospheric signatures of plasmaspheric tails (Foster et al., GRL, 2002), and the other with auroral processes. Such was the case for the October 29-30, 2003 and the November 20, 2003 super-storms. During these very magnetically active periods, the Wide Area Augmentation System (WAAS) of the Federal Aviation Administration (FAA), relying on a GPS-based navigation system was in non-operational status throughout the continental United States (CONUS) for several hours on each of the three days mentioned above. During the next super-storm on November 8, 2004, when WAAS problems of such magnitude occurred, very large phase fluctuations were observed within CONUS. The unusual circumstance for this period was that in this case no appreciable SED was observed. However, the entire CONUS was pervaded by a very wide auroral oval which encompassed even Bear Lake Observatory in Utah and a wide mid-latitude trough with an equatorward location near 40 degrees magnetic latitude. This is clearly visible in GPS TEC and DMSP in-situ density and velocity data. In view of these unexpected results and severe impacts on GPS navigation even during a low sunspot period, the need for the LWS Ionosphere-Thermosphere Storm Probe Mission can hardly be overemphasized.
DE: 2411 Electric fields (2712)
DE: 2439 Ionospheric irregularities
DE: 2471 Plasma waves and instabilities (2772)
DE: 2736 Magnetosphere/ionosphere interactions (2431)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005