Hi Bob,

I've never heard of this before either! A solar flare couldn't directly cause problems with your car and I think it is very unlikely that a geomagnetic storm caused by a solar flare would either.

The reason why geomagnetic storms cause problems with electrical power grids is that the power transmission lines and transformers in power plants are grounded to the Earth. Geomagnetic storms generate strong perturbations to the Earth's magnetic field and generate huge electrical currents in the Earth's magnetosphere and ionosphere. As a result of these currents and magnetic field perturbations, geomagnetic storms can cause geomagnetically induced currents (GIC) in the transmission lines. GIC are a serious problem because they can damage the power grid, causing blackouts.

You may have heard that your car is a safe place to be during a lightning storm because the car is isolated from ground by the rubber tires, and the metal shell of the car is basically a hollow electrical conductor that would shield you if the car were struck by lightning. Because of this, I don't see how GIC could directly harm a standard automobile with an internal combustion engine or cause it to stall.

I looked on the Internet and found some anecdotal evidence that the new hybrid cars have delicate electronic systems that could be damaged by a lightning strike. However, the energy in a lightning strike is very intense, localized and released in such a sudden manner compared to the currents generated by geomagnetic storms. I would guess that a geomagnetic storm probably would not cause difficulties with a hybrid car because the energy of the electrical currents is dissipated slowly over a large area of the Earth, but I don't know for certain.

Kris