The smart guys at the National Space and Aeronautics Administration have proposed two explanations:
ScienceDaily (Jun. 2, 2008) —So there you have it. Jolly old Sol actually heats the Earth's atmosphere with X-rays and ultraviolet radiation. Huh! Who woulda thunk it? And upon closer reading, it may also be a major cause of heartburn.
"It has become clear in recent years that coronal heating is a highly dynamic process, but inconsistencies between observations and theoretical models have been a major source of heartburn. We have now discovered two possible solutions to this dilemma: energy is released impulsively with the right mix of particle acceleration and direct heating, or energy is released gradually very close to the solar surface," says James Klimchuk, an astrophysicist at the Goddard Space Flight Center's Solar Physics Laboratory in Greenbelt, Md.
X-rays and ultraviolet radiation from the solar corona affect Earth and its atmosphere. For satellites, this can be a real drag--literally. As Earth's atmosphere gets hotter, it expands and becomes denser at high altitudes. When this happens, satellites experience more drag, which changes their orbits...
The life of Indigo Red is full of adventure. Tune in next time for the Further Adventures of Indigo Red.