GUMICS

GUMICS is a global solar wind-magnetosphere-ionosphere coupling model. Its solar wind and magnetospheric part is based on solving the ideal MHD equations and its ionosphere part is based on solving the electrostatic current continuity equation. Advanced numerical methods such as automatically refined Cartesian octogrid and temporal subcycling are used to speed up the computation. The computational box is from -224 to +32 Earth radii in GSM X and from -64 to +64 Earth radii in Y and Z.

MHD describes the large-scale behaviour of the magnetosphere. Quantities such as location and intensity of the bow shock, magnetosphere and tail current sheet come out reliably from the model, whereas quantities depending on non-MHD physics (such as Hall physics) are not reliable (for example, the reconnection rate in the tail). The cross polar cap potential found with GUMICS has been found to be consistent with observations. Among the chief uncertainties are the strength of the Region-2 current system and the behaviour of the inner magnetosphere more generally.

Solar wind density, velocity and temperature as well as interplanetary magnetic field components.

Magnetosphere: Primary predicted quantities are plasma density, pressure, velocity and magnetic field vector in space and time. Ionosphere: Height-integrated Pedersen and Hall conductances, ionospheric potential, ionospheric electric field, precipitation power, Joule heating power, field-aligned currents, in space and time.