Comparison of predictive estimates of high-latitude electrodynamics with observations of global-scale Birkeland currents
| Autor: | Brian J. Anderson, C. L. Waters, Daniel T. Welling, Joachim Raeder, Viacheslav Merkin, Haje Korth, Lutz Rastaetter, Robin J. Barnes, Antti Pulkkinen, Michael Wiltberger |
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| Rok vydání: | 2017 |
| Předmět: |
Physics
Geomagnetic storm Atmospheric Science 010504 meteorology & atmospheric sciences Magnetosphere Geophysics Space weather Atmospheric sciences 01 natural sciences Latitude Quantum electrodynamics Physics::Space Physics 0103 physical sciences Substorm Ionosphere Magnetohydrodynamics Ampere 010303 astronomy & astrophysics 0105 earth and related environmental sciences |
| Zdroj: | Space Weather. 15:352-373 |
| ISSN: | 1542-7390 |
| Popis: | Two of the geomagnetic storms for the Space Weather Prediction Center (SWPC) Geospace Environment Modeling (GEM) challenge [cf. Pulkkinen et al., 2013] occurred after data were first acquired by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). We compare Birkeland currents from AMPERE with predictions from four models for the 4-5 April 2010 and 5-6 August 2011 storms. The four models are: the Weimer [2005b] field-aligned current statistical model; the Lyon-Fedder-Mobarry magnetohydrodynamic (MHD) simulation; the Open Global Geospace Circulation Model MHD simulation; and the Space Weather Modeling Framework MHD simulation. The MHD simulations were run as described in Pulkkinen et al. [2013] and the results obtained from the Community Coordinated Modeling Center (CCMC). The total radial Birkeland current, ITotal, and the distribution of radial current density, Jr, for all models are compared with AMPERE results. While the total currents are well correlated, the quantitative agreement varies considerably. The Jr distributions reveal discrepancies between the models and observations related to the latitude distribution, morphologies, and lack of nightside current systems in the models. The results motivate enhancing the simulations first by increasing the simulation resolution, and then by examining the relative merits of implementing more sophisticated ionospheric conductance models, including ionospheric outflows or other omitted physical processes. Some aspects of the system, including substorm timing and location, may remain challenging to simulate, implying a continuing need for real-time specification. |
| Databáze: | OpenAIRE |
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