HR: 14:25h
AN: GP23B-04    [Abstracts]
TI: 3-Dimensional Modeling of Ionospheric Current
AU: Pi, X
EM: Xiaoqing.Pi@jpl.nasa.gov
AF: NASA Jet Propulsion Laboratory, M/S 138-308 4800 Oak Grove Drive, Pasadena, CA 91109
AU: * Raymond, C A
EM: Carol.A.Raymond@jpl.nasa.gov
AF: NASA Jet Propulsion Laboratory, M/S 138-308 4800 Oak Grove Drive, Pasadena, CA 91109
AU: Mannucci, A J
EM: Anthony.J.Mannucci@jpl.nasa.gov
AF: NASA Jet Propulsion Laboratory, M/S 138-308 4800 Oak Grove Drive, Pasadena, CA 91109
AU: Hajj, G A
EM: George.A.Hajj@jpl.nasa.gov
AF: NASA Jet Propulsion Laboratory, M/S 138-308 4800 Oak Grove Drive, Pasadena, CA 91109
AU: Sabaka, T J
EM: sabaka@geomag.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, Geodynamics Branch Code 921, Greenbelt, MD 20771
AB: A 3-dimensional ionospheric current model (3D-ICM) is under development aimed at modeling magnetic fields in the Earth's space environment due to ionospheric currents. The effort is complementary to the existing comprehensive models, such as CM4, that attempt to separate magnetic field components of internal and external (ionospheric and magnetosphere) origins by fitting satellite and ground observatory measurements of the magnetic field. The motivation for 3D-ICM is to provide an alternative method to separate the ionospheric dynamic effects by using space environment measurements and ionospheric as well as upper atmospheric models. It is also anticipated that success of such an effort will enable to resolve higher precision time-variation in the main field, and allow better estimation of Earth's conductivity structure. The 3D-ICM consists of a physics-based model for the currents, and assimilative and empirical models for ionospheric and upper atmospheric conditions. The physics model computes vector ionospheric currents in the E and F regions after specifying ionospheric conductivities, electric fields, thermospheric winds, and the diamagnetic effects on a 3-D grid. These parameters can be estimated from empirical or assimilative models of the ionosphere and upper atmosphere, using historical or present measurements from space and Earth science missions. With empirical models, 3D-ICM can be used to predict the climate trend of ionospheric currents, which varies with longitude, season, and solar cycle. For estimating present conditions, assimilative models will be applied for optimal estimation of the driving parameters, by assimilating a variety of data types such as GPS-derived total electron content. This will bring a space weather modeling capability to 3D-ICM. This paper will report the development strategy and present examples of climatic predictions by 3D-ICM. Comparisons of modeling results between 3D-ICM and CM4 will also be presented to address modeling issues related to different approaches.
DE: 2409 Current systems (2721)
SC: Geomagnetism and Paleomagnetism [GP]
MN: Fall Meeting 2005