14 DAY TRIAL // The planet's atmosphere is heavily influenced by variations that may occur in the Sun's total energy output, says a new study conducted by experts at the National Center for Atmospheric Research.
Based in Boulder, Colorado, the NCAR was founded and is supported by the US National Science Foundation (NSF), which also provided the money needed for the new investigation.
Just recently, the team says, s steep drop recorded in the amounts of ultraviolet radiation the Sun emitted was linked with a temporary shrinking of the highest parts of our planet's atmosphere.
Working in collaboration with colleagues from the University of Colorado at Boulder (UCB), the NCAR team determined that the level of magnetic activity the Sun display may in fact vary more than previously thought, throughout the star's 11-year cycle.
“This research makes a compelling case for the need to study the coupled Sun-Earth system, and to illustrate the importance of solar influences on our terrestrial environment with both fundamental scientific implications and societal consequences,” says Farzad Kamalabadi.
The expert is the program director of the Division of Atmospheric and Geospace Sciences. Details of the work appear in the latest issue of the esteemed scientific journal Geophysical Research Letters.
In addition to the NSF, the American space agency NASA also contributed to funding the research.
“Our work demonstrates that the solar cycle not only varies on the typical 11-year time scale, but also can vary from one solar minimum to another. All solar minima are not equal,” adds Stanley Solomon.
He holds an appointment as a research scientist at the NCAR High Altitude Observatory, and is also the lead author of the new investigation. The expert believes the new data carry considerable implications for the safety of satellites and the International Space Station (ISS).
The study revealed that the thermosphere is directly and immediately affected by changes in the amount of UV light the Sun outputs.
“With lower thermospheric density, our satellites will have a longer life in orbit,” says study coauthor, UCB professor Thomas Woods.
He explains that, as the density of the thermosphere decreases, more and more asteroids will be able to persist in this atmospheric layer for longer periods of time.
The density decrease “is good news for those satellites that are actually operating, but it is also bad because of the thousands of non-operating objects remaining in space that could potentially have collisions with our working satellites,” he explains further.
“It is now clear that the record low temperature and density were primarily caused by unusually low levels of solar radiation at the extreme-ultraviolet level,” concludes Solomon.