HR: 09:43h
AN: SA51C-06    [Abstracts]
TI: Modeling the Effect of Changes in the Terrestrial Magnetic Field on the Climatology of the Mid- and Low-Latitude Ionosphere.
AU: * Millward, G H
EM: george.millward@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics, 1234 Innovation Drive, Boulder, CO 80303, United States
AU: Richmond, A D
EM: richmond@hao.ucar.edu
AF: High Altitude Observatory, National Center for Atmospheric Physics, Boulder, CO , United States
AU: Fuller-Rowell, T J
EM: tim.fuller-rowell@noaa.gov
AF: CIRES, NOAA Space Environment Center, 325 Broadway, Boulder, CO , United States
AU: Aylward, A D
EM: alan@apl.ucl.ac.uk
AF: Department of Physics and Astronomy, University College London, London, United Kingdom
AB: A new model of the global ionosphere has been developed which utilizes a magnetic field structure derived directly from the full International Geomagnetic Reference Field (IGRF) - as opposed to earlier, dipolar approximations to the IGRF. Using this new model, a series of runs has been undertaken to investigate how the ionosphere has been influenced by changes in the Terrestrial magnetic field over the 40 years from 1965 to 2005. For each run, all inputs to the model, such as thermospheric composition and winds, and the Solar EUV flux are kept the same. The only change comes from the magnetic field, with values taken from the IGRF at the relevant year. The results are very interesting: In most regions the changes to the ionosphere since 1965 are fairly insignificant. However within the equatorial region of South America and the South Atlantic it is a different story. Here the changes are very significant and therefore need to be considered in any analysis of long term trends within the ionosphere. Results from the modeling study will be presented and an analysis, in terms of changes in the location of the magnetic equator and the magnetic declination and inclination, will be discussed.
DE: 2415 Equatorial ionosphere
DE: 2447 Modeling and forecasting
SC: SPA-Aeronomy [SA]
MN: 2007 Joint Assembly