November’s Monthly Media comes from Dr Chris Jordan and his collaborators Dr John Morgan and 3rd year student Angelica Waszewski, on some wild ionospheric activity observed on the 31st of October 2013 by the Murchison Widefield Array (MWA) while searching for the Epoch of Reionisation. This activity was found by analysing ionospheric data across several years in conjunction with space weather data from near-Earth satellites.

Previous Monthly Media have discussed how the MWA data is used to understand the Earth’s ionosphere (upper atmosphere) and what causes changes in it. The ionospheric event recorded by the MWA on the 31st of October, 2013 has some evidence that space weather events (the effect of the Sun’s radiation on the Earth’s magnetic field) may be related to ionospheric events.

The below plot shows data from this event in 2013, relating ionospheric activity measured by the MWA to space weather data measured by near-Earth satellites.

Ionospheric magnitude vs time. The higher the points are, the worse the ionosphere is considered. The colours indicate the magnetic field alignment as recorded by space weather spacecraft, with higher (more yellow) being more aligned. Although there are a few events with large ionospheric magnitudes, only two have yellower colours, which suggests that there could be a coincidence in MWA ionospheric activity and space weather. We focus on the left-most highlighted event.

A possible cause-and-effect of this correlation might be attributed to the solar wind; helioweather.net shows a number of simulations to help indicate what solar ejecta and magnetic fields are doing in the inner part of the solar system (which Earth is within). The below GIF is a snapshot of the relevant movie at the time of the event highlighted on the left of the above plot.

The space weather events observed by near-Earth satellites, pausing on the relevant observation on the 31st of October 2013. Original video available here.

We cannot conclusively say that what we can see with the MWA is related to the solar wind. As seen in the first plot, there are many “spikes” of activity with dark colours, indicating that most spikes of activity are not aligned to magnetic fields. But, maybe MWA ionospheric activity can be triggered by solar wind, and the other events are triggered by something else. More research required!