HR: 1340h
AN: SA33A-1142    [Abstracts]
TI: Comparison Between GAIM and LLIONS in the Jicamarca Low Latitude Sector During the First CAWSES Space Weather Campaign
AU: * Anderson, D N
EM: david.anderson@noaa.gov
AF: University of Colorado/CIRES, NOAA/Space Environment Center 325 Broadway, Boulder, CO 80303 United States
AU: Anghel, A
EM: adela.anghel@noaa.gov
AF: University of Colorado/CIRES, NOAA/Space Environment Center 325 Broadway, Boulder, CO 80303 United States
AU: Sojka, J J
EM: sojka@gaim.cass.usu.edu
AF: Center for Atmospheric and Space Sciences, Utah State University, 4405 Old Main Hill, Logan, UT 84322 United States
AU: Schunk, R W
EM: schunk@cc.usu.edu
AF: Center for Atmospheric and Space Sciences, Utah State University, 4405 Old Main Hill, Logan, UT 84322 United States
AU: Scherliess, L
EM: ludger@gaim.cass.usu.edu
AF: Center for Atmospheric and Space Sciences, Utah State University, 4405 Old Main Hill, Logan, UT 84322 United States
AU: Thompson, D C
EM: thompson@cc.usu.edu
AF: Center for Atmospheric and Space Sciences, Utah State University, 4405 Old Main Hill, Logan, UT 84322 United States
AU: Eccles, V
EM: vince@spacenv.com
AF: Space Environment Corporation, 221A Springcreek Parkway, Providence, UT 84332 United States
AB: The Utah State University (USU) Global Assimilation of Ionospheric Measurements (GAIM) Model has been compared to the Space Environment Corporation (SEC) Low Latitude IONospheric Sector (LLIONS) model for the period 20 March 2004 through 14 April 2004. This period includes the first CAWSES space weather period. The objective of this comparison is to assess how the data assimilation in the GAIM Kalman filter is able to reorganize the low-latitude ionospheric morphology, specifically the locations and intensities of the Equatorial Anomaly peaks. The LLIONS approach uses observations in the Jicamarca sector to modify the electric field driver, which is the dominant transport mechanism for the equatorial ionosphere. In this study, the observations from magnetometers and digisondes are only able to modify the vertical ExB drift velocities during sunlit conditions. Hence, the primary comparisons are for daytime low latitudes along the Jicamarca longitude sector. At night, only the GAIM assimilation reveals the marked structuring of the equatorial ionosphere. Results are presented contrasting a range of geomagnetic quiet-to-disturbed conditions. These comparisons include not only TEC, but also F-region electron density profiles as a function of latitude and local time.
DE: 2415 Equatorial ionosphere
DE: 2437 Ionospheric dynamics
DE: 2447 Modeling and forecasting
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting