A Citizen Science Magnetic Observatory located in Dunedin, New Zealand.
The Long Term Magnetogram
A high resolution annotated version of this plot is available here. 3Mb in size!
This chart shows a range of activity over the past 365 days.
- Geomagnetic Activity: This is a unitless measure of the rate of change of the magnetic field. A large change is usualy due to space weather.
- Storm Detected: High levels of geomagnetic activity are called a magnetic storm. Aurora are typically visible when this is happening. The computer plots a marker when we reach this empirically determined threshold.
- Aurora Sighted: This marker plots notifications from New Zealand and Tasmania that an aurora was observed.
- Equinoxes: This marks the spring and autumn equinoxes. At these points in the Earth's orbit, our magnetic field is tilted in such a way that we are more susceptible to solar plasma leaking in and causing an aurora. We should see increases in magnetic activity and aurora sightings around these times of the year.
- Carrington Rotation: Some solar features that generate space weather can be long lasting - coronal holes and sunspots for example. The average rate of rotation of the sun is about 27 days, so this marker plots solar rotation.
- CME: Coronal-Mass Ejections are titanic expulsions of solar plasma. If directed our way, they can cause intense auroral displays. This marker tracks Earth-facing CMEs over the course of the year. We should expect to see an increase in magnetic storms and auroral displays a few days after a CME launches from the Sun.