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| Titel |
Metrics study of the GUMICS-4 global MHD code using empirical relationships |
| VerfasserIn |
Evgeny Gordeev, Gabor Facsko, Victor Sergeev, Minna Palmroth, Ilja Honkonen |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250078092
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| Zusammenfassung |
| Global MHD modeling is a powerful tool in space physics research. There are several advanced and still developing global MHD codes that are used widely to simulate plasma processes and investigate solar wind magnetosphere-ionosphere interaction. The validation of simulation results is still a very important but difficult problem. We present an approach for systematic and quantitative testing of code performance, which is based on statistical empirical dependencies of the key magnetospheric parameters obtained from real observations. We demonstrate it on the example of testing the GUMICS-4 global MHD code. As a part of FP-7 ECLAT project a large set of nearly-stationary solutions (162 runs) with different stationary IMF/solar wind inputs has been generated for different dipole tilts and levels of solar EUV radiation, and the values of key parameters obtained in each run are compared to the parameter values computed from previously published empirical relations. As the key parameters we use the principal large-scale characteristics of the magnetosphere which characterize the magnetopause size and shape, geometry of the tail neutral sheet, magnetotail plasma pressure, tail lobe magnetic field, and cross polar cap electric potential. We found that the set of GUMICS-4 stationary solutions in most cases satisfactorily fit the empirical relations (both in their dependencies and values), however, with some peculiarities. Particularly, position of the subsolar magnetopause, neutral sheet shape and position, and the plasma sheet pressure agree well with statistical models. At the same time, the size of the tail magnetopause and the lobe magnetic field magnitude appear to be systematically lower compared to their empirical values, resulting in lower magnetic flux in the magnetotail. Also, the ionospheric potential value has smaller magnitude and low range of variations compared to empirical relations. These results as well as further development of validation procedures are briefly discussed. |
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