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Home > All Images > 2001 > December > 5 Dec 2001

Images Dated 5th December 2001

Available as Framed Photos, Photos, Wall Art and Gift Items

Choose from 22 pictures in our Images Dated 5th December 2001 collection for your Wall Art or Photo Gift. Popular choices include Framed Photos, Canvas Prints, Posters and Jigsaw Puzzles. All professionally made for quick delivery.

Riometer information board Featured 5 Dec 2001 Print

Riometer information board

Riometer information board at Poker Flat Research Range (PFRR), Alaska, USA. A riometer is used in polar regions to study aurorae, the solar-induced electromagnetic storms of the polar ionosphere. The ionosphere is a region of the upper atmosphere that lies 50-600 kilometres above Earth's surface. A riometer is an array of radio antennae. Riometer stands for Relative Ionospheric Opacity Meter using Extra-Terrestrial Electromagnetic Radiation. As the glowing displays of the aurorae (visible at night) block the passage of radio waves from space to the Earth, they will be seen as shadows on the riometer output screen. PFRR is operated by the University of Alaska's Geophysical Institute