Perhaps you wake up to a good morning text from someone, or send one yourself. Or maybe you check your work emails on your laptop. Or have a cup of coffee waiting for you, already made by your programmable Keurig machine.
All of these things have one thing in common; they all involve electricity. For most people in the United States or similar societies, no one thinks about the electricity flowing into their homes, except perhaps when they have to pay the bills, or a large storm is predicted. However, there is something else that can affect your electrical supply which doesn’t occur to most people; the sun.
Yes, the sun. On occasion the sun sends out a bubble of plasma, known as a coronal mass ejection, or CME. These interact with the Earth’s geomagnetic field, creating what are called geomagnetic disturbances (GMD). The results of this is not always alarming; it is the cause of the beautiful aurora.
CMEs can also destroy transformers and cause blackouts.
Suddenly your Keurig machine doesn’t work, you cannot recharge your phone, and the laptop is draining battery as well.
Everything electronic is in danger, from the satellites that tell your GPS where you are, to the transmission lines that power your outlets. Consider how much of everyday life includes electricity. I started off with three examples that could be done within ten minutes of each other. Many people are incredibly dependent on electricity for their everyday lives, and any disruption in that would have profound consequences.
While I have written about geomagnetic storms before, that focused mostly on the strength and frequency of these events. Here, I turn to some of its effects on the ground. GMDs create geomagnetically induced currents, or GICs. GICs create currents in railways, power lines, and communication cables that are not normally running through these systems. These can result in power outages and damage to transformers.
So, what can we do about all this? Right now, the answer is ‘not much’. There is no way to stop the sun from creating CMEs. We cannot change the laws of physics so that GICs are not created. We can, however, at least get an idea of how likely this scenario is, and try to be prepared. That brings us to today’s featured article, “Surface electric fields for North America during historical geomagmetic storms” by Lisa H Wei, Nicole Homeier, and Jennifer L Gannon. Published in the American Geophysical Union’s publication Space Weather in 2013, this article looks at two storms that have already happened.
The two storms chosen in this article are the 1989 “Quebec” storm, which occurred in March of that year, and the 2003 “Halloween” storms, named due to their proximity to that date. Both storms had a large impact on the power grid. The Quebec storm affected the Hydro-Quebec power grid; six million without power and billions of dollars in economic cost, from just nine hours with the grid down. The Halloween storm caused blackouts and damaged transformers.
For the Halloween storm, the authors took magnetic field data from the International Real-Time Magnetic Observatory (Intermagnet). Since these records only go back to 1991, another source was needed for the Quebec storm data, which was SuperMAG. While both of these gave information only from the sparsely located magnetic observatories, it allowed the authors to use a technique known as the Spherical Elementary Current System, or SECS. SECS allowed them to take the geographically scattered data points and build a map of the entire magnetic field across the United States and Canada for both of these storms. This information was used in conjunction with resistivity maps from the United States Geological Survey (USGS). Resistivity is a measure of how much a material ‘pushes back’, making it more difficult for current to flow through. These USGS maps do not show local nonconformities, but for an overall look at all of North America, work well. They were supplemented with other resistivity models so that Canada was also included in the research.
Likely due to the high resistivity, it was found that the east coast of the United States, as well as certain parts of Canada (Manitoba and Quebec) have higher changes in their electric fields as compared to the rest of the continent. Yes, I do mean electric; magnetism and electricity are linked in a way beyond the scope of this blog; a change in one will create the other, and remember that Earth has a magnetic field controlled by the motion of liquid metal in the planet’s core.
The maps produced by this study can help identify at-risk regions and let us make preparations. In theory, using such data in real-time could allow for smaller-scale risks (such as individual transformers) to be realized, and take precautions against them. There is still a lot of research to be done. People are working on predicting these events and how to mitigate the effects–possibly while sipping Keurig-made coffees.