HR: 11:50h
AN: SM11D-06    [PDF]
TI: "Nudging" the Salammbo Code: First results of seeding a diffusive radiation belt code with in situ data: GPS, GEO, HEO and POLAR
AU: * Friedel, R H
EM: friedel@lanl.gov
AF: Los Alamos National Laboratory, MS D 436, Los Alamos, NM 87544 United States
AU: Bourdarie, S
EM: sbourdar@onecert.fr
AF: ONERA-CERT/DESP, BP 4025 2, Avenue Edouard Belin 31055 Toulouse Cedex 4, Toulouse, 31055 France
AU: Fennell, J
EM: joseph.fennell@aero.org
AF: Aerospace Corporation, El Segundo, Los Angeles, CA 90009-2957 United States
AU: Kanekal, S
EM: kanekal@surya.umd.edu
AF: Catholic University of America, Dept of Physics, Univ. of Maryland, College Park, MD 20742 United States
AU: Cayton, T E
EM: tcayton@lanl.gov
AF: Los Alamos National Laboratory, MS D 436, Los Alamos, NM 87544 United States
AB: The Salammbo coded is a diffusive radiation belt code aimed at representing the dynamics of relativistic electrons in the inner magnetosphere. The code currently incorporates physics capturing the majority of the observed dynamics, but does not include all proposed mechanisms that could be responsible for some of the detailed dynamics observed - in particular, it does not include chorus acceleration. However, we do have at our disposal a range of data taken in situ. Traditionally diffusive models use data as boundary conditions only. We here use properly inter-calibrated data from a range of LANL geosynchronous and GPS particle instruments whenever they are available to seed or "nudge" the code, allowing the code in effect to act as a physics based interpolater of the data. This process yields a data/model global synthesis representation of the state of the relativistic electron belts that is better than any representation that can currently be achieved from models or data alone, in spite of some "missing physics". We present here the data ingestion methods used and first runs of this new synthesis model. We test this model against in-situ measurements of spacecraft not part of the assimilation process: In general the synthesis model is able to reproduce measured in-situ fluxes to within a factor of two, irrespective of activity level. This is of the same order as the fidelity of our spacecraft inter-calibration and thus as good as one can be expected to do. We are thus able to produce a high fidelity state of the global magnetosphere against which this and other physics based models may be compared.
DE: 2720 Energetic particles, trapped
DE: 2730 Magnetosphere--inner
DE: 2740 Magnetospheric configuration and dynamics
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting