The Average Magnetic field and Polar current System model (AMPS) is a project in response to Swarm DISC (Data, Innovation and Science Cluster) ITT 1.3 "Production and visualisation of a climatological model of high-latitude ionospheric and field aligned current systems".

The outcome of this project is a new climatological model of polar ionospheric currents, based on magnetic field measurements from the CHAMP and Swarm satellites. The model is a representation of the global disturbance magnetic field associated with ionospheric currents, as a function of solar wind speed, the interplanetary magnetic field, the tilt angle of the Earth's magnetic dipole, and the F10.7 solar flux index. The ionospheric current system, and an estimate of the magnetic disturbances on ground, can be derived from the model coefficients. This is an advancement compared to earlier empirical models because the full horizontal current density can be derived directly from magnetic field measurements, without any assumption about conductivity or electric fields.

The AMPS model is valid in both hemispheres, and no assumptions about hemispheric symmetries have been applied. For this reason, and since we have corrected for variations in Earth's magnetic field, the model can be used to do precise comparisons of the ionospheric current system in the two hemispheres.

Documentation

Download project documents:

• Swarm AMPS product description
• Swarm AMPS processing algorithm description
• Swarm AMPS validation report
• Python forward code for model Average Magnetic field and Polar current System - code used to calculate model magnetic field and currents for a given set of input parameters.
• pyAMPS's documentation - documentation for the code
• Web-interface for the model - you can plot the model current system or magnetic field disturbances on polar maps in the two hemispheres. The model output can be changed using drop-down menus, and the input can be changed by adjusting sliders or by clicking a plot of the solar wind conditions from the previous 24 hours.

Useful model information

• A paper describing the model in Journal of Geophysical Research (open access)
• AMPS model blog

Project duration: September 2017 - August 2018. This project was funded by ESA via the Swarm DISC, Sub-Contract No. SW-CO-DTU-GS-113.