The ineffectiveness of Joule heating in the stratosphere

Several papers have recently invoked Joule heating in the stratosphere, generated from electric currents induced by solar wind interactions with Earth, as possibly playing a significant role in warming the polar stratosphere. This commentary assesses the accuracy of that contention and demonstrates that in situ Joule heating can take no significant part in warming the stratosphere, and thus cannot be used to suggest a link between stratospheric temperatures and solar activity.