F region

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noun

the ionospheric region in which the F layer forms.

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Origin of F region

First recorded in 1925–30

Words nearby F region

freezing point, freezing rain, freezing works, free zone, Frege, F region, Frei, Freiberg's disease, Freiburg, freight, freightage

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use F region in a sentence

The program has not made a final selection on which upgrades will actually be included in future versions of the F-35.
Pentagon Misfires in Stealth Jet Scandal|Dave Majumdar|January 8, 2015|DAILY BEAST
That article noted that the F-35 does not currently have the ability to down-link live video to ground troops,.
Pentagon Misfires in Stealth Jet Scandal|Dave Majumdar|January 8, 2015|DAILY BEAST
In fact, according to F-35 program sources, the next software upgrades are not yet fully defined nor are they fully funded.
Pentagon Misfires in Stealth Jet Scandal|Dave Majumdar|January 8, 2015|DAILY BEAST
Therefore, it is not possible for any F-35 schedule to include a video data link or infrared pointer at this point.
Pentagon Misfires in Stealth Jet Scandal|Dave Majumdar|January 8, 2015|DAILY BEAST

And that may well be what is happening in the Barnett Shale region around, yes, Dallas and Irving.
26 Earthquakes Later, Fracking’s Smoking Gun Is in Texas|James Joiner|January 7, 2015|DAILY BEAST
Within the past thirty years civilization has rapidly taken possession of this lovely region.
Among the Sioux|R. J. Creswell
E was an Esquire, with pride on his brow; F was a Farmer, and followed the plough.
Boys and Girls Bookshelf; a Practical Plan of Character Building, Volume I (of 17)|Various
Nowhere can be found a region capable of supporting a larger population to the square mile than Lombardy.
Glances at Europe|Horace Greeley
From that region they issue to inflict diseases, especially blindness and deafness.
Solomon and Solomonic Literature|Moncure Daniel Conway
At that time, the postage on letters from that region was very high, sometimes as much as fifty or sixty cents, or even a dollar.
The Boarded-Up House|Augusta Huiell Seaman

British Dictionary definitions for F region

F region

noun

the highest region of the ionosphere, extending from a height of about 150 kilometres to about 1000 kilometres. It contains the highest proportion of free electrons and is the most useful region for long-range radio transmissionAlso called: Appleton layer See also ionosphere

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for F region

F region

The highest region of the ionosphere, consisting of free electrons generated by the ionizing effect of solar radiation. This region is subdivided into two layers, designated the F1 layer, and the F2 layer. The F1 layer extends from about 150 km (93 mi) to 240 km (149 mi) above the surface of the Earth and exists only during sunlight hours. At night it merges into the F2 layer. The F2 layer extends from about 240 km (149 mi) to 400 km (248 mi). The density of free electrons in this layer is much higher than it is in the F1 layer. It is the main reflecting layer for high frequency communications, both during sunlight hours and during the night. Also called F layer See also ionosphere.