This image obtained by the TIMED Global Ultraviolet Imager — the only NASA instrument currently imaging the Earth's aurora and upper atmosphere from space — shows an aurora, superimposed over an Earth image, produced by a major geomagnetic storm that occurred on April 14, 2006. The solar storm occurred during solar minimum, the least active part of the 11-year solar cycle, which was once considered to be the time when scientists could measure the "baseline" or quiescent state of the upper atmosphere.
But as this image shows, major storms can still occur during such "quiet" times. The April 14th storm occurred due to changes in the geomagnetic field produced by a co-rotating interaction region that propagated out from the sun. The impact of this storm was seen in disturbed conditions in the Earth's upper atmosphere and ionosphere, and over the continental United States.
TIMED's systematic global measurements of the upper atmosphere show that the atmosphere is continually subjected to solar-induced disturbances leading scientists to ask whether there truly is a quiescent state of the upper atmosphere.
Credit: Johns Hopkins University Applied Physics Laboratory
To save photo: