Also found in: Thesaurus, Encyclopedia.


The outermost layer of the atmosphere, between the mesosphere and interplanetary space, where air becomes extremely thin and temperatures increase steadily with altitude.

ther′mo·spher′ic (-sfîr′ĭk, -sfĕr′ĭk) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Physical Geography) pertaining to the thermosphere
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
He and his comembers from India, Ethiopia, Mexico, Peru and Tunisia worked on the Nanosatellite for Thermospheric Atomic Composition and Density Measurements I Nanosat, which aims to study the composition of the upper and lower thermosphere through mass spectrometry.
Lean, "Thermospheric densities derived from spacecraft orbits: Accurate processing of two-line element sets," Journal of Geophysical Research: Space Physics, vol.
Although the low solar and geomagnetic activity could not lead to the ionospheric anomalies during the seismic event, due to the thermospheric dynamics caused by various types of atmospheric disturbances the TEC may generate significant day to day variation even during magnetically quiet period (Zhou et al., 2009).