### Abstract

We present a new scheme for solving the ionospheric boundary conditions required in magnetospheric MHD simulations. In contrast to the electrostatic ionospheric solvers currently in use, the new solver takes ionospheric induction into account by solving Faraday's law simultaneously with Ohm's law and current continuity. From the viewpoint of an MHD simulation, the new inductive solver is similar to the electrostatic solvers, as the same input data is used (field-aligned current [FAC] and ionospheric conductances) and similar output is produced (ionospheric electric field). The inductive solver is tested using realistic, databased models of an omega-band and westward traveling surge. Although the tests were performed with local models and MHD simulations require a global ionospheric solution, we may nevertheless conclude that the new solution scheme is feasible also in practice. In the test cases the difference between static and electrodynamic solutions is up to ∼10 V kmg^{-1} in certain locations, or up to 20-40% of the total electric field. This is in agreement with previous estimates. It should also be noted that if FAC is replaced by the ground magnetic field (or ionospheric equivalent current) in the input data set, exactly the same formalism can be used to construct an inductive version of the KRM method originally developed by Kamide et al. (1981).

Original language | English |
---|---|

Pages (from-to) | 97-108 |

Number of pages | 12 |

Journal | Annales Geophysicae |

Volume | 29 |

Issue number | 1 |

DOIs | |

Publication status | Published - Jan 19 2011 |

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### All Science Journal Classification (ASJC) codes

- Astronomy and Astrophysics
- Geology
- Atmospheric Science
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science

### Cite this

*Annales Geophysicae*,

*29*(1), 97-108. https://doi.org/10.5194/angeo-29-97-2011

**Inductive ionospheric solver for magnetospheric MHD simulations.** / Vanhamäki, H.

Research output: Contribution to journal › Article

*Annales Geophysicae*, vol. 29, no. 1, pp. 97-108. https://doi.org/10.5194/angeo-29-97-2011

}

TY - JOUR

T1 - Inductive ionospheric solver for magnetospheric MHD simulations

AU - Vanhamäki, H.

PY - 2011/1/19

Y1 - 2011/1/19

N2 - We present a new scheme for solving the ionospheric boundary conditions required in magnetospheric MHD simulations. In contrast to the electrostatic ionospheric solvers currently in use, the new solver takes ionospheric induction into account by solving Faraday's law simultaneously with Ohm's law and current continuity. From the viewpoint of an MHD simulation, the new inductive solver is similar to the electrostatic solvers, as the same input data is used (field-aligned current [FAC] and ionospheric conductances) and similar output is produced (ionospheric electric field). The inductive solver is tested using realistic, databased models of an omega-band and westward traveling surge. Although the tests were performed with local models and MHD simulations require a global ionospheric solution, we may nevertheless conclude that the new solution scheme is feasible also in practice. In the test cases the difference between static and electrodynamic solutions is up to ∼10 V kmg-1 in certain locations, or up to 20-40% of the total electric field. This is in agreement with previous estimates. It should also be noted that if FAC is replaced by the ground magnetic field (or ionospheric equivalent current) in the input data set, exactly the same formalism can be used to construct an inductive version of the KRM method originally developed by Kamide et al. (1981).

AB - We present a new scheme for solving the ionospheric boundary conditions required in magnetospheric MHD simulations. In contrast to the electrostatic ionospheric solvers currently in use, the new solver takes ionospheric induction into account by solving Faraday's law simultaneously with Ohm's law and current continuity. From the viewpoint of an MHD simulation, the new inductive solver is similar to the electrostatic solvers, as the same input data is used (field-aligned current [FAC] and ionospheric conductances) and similar output is produced (ionospheric electric field). The inductive solver is tested using realistic, databased models of an omega-band and westward traveling surge. Although the tests were performed with local models and MHD simulations require a global ionospheric solution, we may nevertheless conclude that the new solution scheme is feasible also in practice. In the test cases the difference between static and electrodynamic solutions is up to ∼10 V kmg-1 in certain locations, or up to 20-40% of the total electric field. This is in agreement with previous estimates. It should also be noted that if FAC is replaced by the ground magnetic field (or ionospheric equivalent current) in the input data set, exactly the same formalism can be used to construct an inductive version of the KRM method originally developed by Kamide et al. (1981).

UR - http://www.scopus.com/inward/record.url?scp=78651380134&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=78651380134&partnerID=8YFLogxK

U2 - 10.5194/angeo-29-97-2011

DO - 10.5194/angeo-29-97-2011

M3 - Article

AN - SCOPUS:78651380134

VL - 29

SP - 97

EP - 108

JO - Annales Geophysicae

JF - Annales Geophysicae

SN - 0992-7689

IS - 1

ER -