Above the ozone layer, the ionosphere is a part of Earth’s atmosphere where particles have been cooked into a sea of electrically-charged electrons and ions by the Sun’s radiation. The ionosphere is co-mingled with the very highest — and quite thin — layers of Earth’s neutral upper atmosphere, making this region an area that is constantly in flux undergoing the push-and-pull between Earth’s conditions and those in space. Increasingly, these layers of near-Earth space are part of the human domain, as it’s home not only to astronauts, but to radio signals used to guide airplanes and ships, and satellites that provide our communications and GPS systems. Understanding the fundamental processes that govern our upper atmosphere and ionosphere is crucial to improve situational awareness that helps protect astronauts, spacecraft and humans on the ground.
GOLD, in geostationary orbit over the Western Hemisphere, will build up a full-disk view of the ionosphere and upper atmosphere every half hour, providing detailed large-scale measurements of related processes — a cadence which makes it the first mission to be able to monitor the true weather of the upper atmosphere. GOLD is also able to focus in on a tighter region and scan more quickly, to complement additional research plans as needed.
Music credits: 'Faint Glimmer' by Andrew John Skeet [PRS], Andrew Michael Britton [PRS], David Stephen Goldsmith [PRS], 'Ocean Spirals' by Andrew John Skeet [PRS], Andrew Michael Britton [PRS], David Stephen Goldsmith [PRS] from Killer Tracks.
Bright swaths of red and green, known as airglow, are visible in this time-lapse view of Earth's limb captured from the International Space Station. Airglow occurs when gases in the upper atmosphere become charged by the Sun's radiation, emitting light. By measuring the light from airglow, ICON and GOLD will learn a lot about the neutral and charged particles in the upper atmosphere.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 188.8.131.52.0