Earth  Sun  ID: 2891

Aurora over the North Pole on April 17, 1999 (WMS)

When the charged particles flowing outward from the Sun (the solar wind) hit the Earth's magnetic field, they are channeled down the magnetic field lines to the ionosphere at the North and South Poles. The impact of these particles on atmospheric molecules causes the molecules to emit light, which forms the visible aurora. This visualization shows the development of the aurora over the North Pole for about three hours on April 17, 1999, as seen by the ultraviolet VIS Earth Camera on the POLAR spacecraft. The two main features of these ultraviolet images are the very bright ultraviolet emission from the reflected solar radiation on the dayside of the Earth and the bright ring of the auroral oval circling the North Pole. The aurora seen in this visualization is the diffuse aurora, a very large bright band that is actually too dim to be seen well from the ground by the human eye. What we normally think of as the aurora are the even brighter curtains of light within the diffuse auroral caused by very energetic electrons. These curtains are too small to be seen in this image. The diffuse aurora appears as a ring around the pole rather than as a bright spot over the entire pole because the solar particles actually spend extended time wandering about within the Earth's magnetic field before traveling down a very select set of magnetic field lines to the Earth. Near the end of this three hour period, the spacecraft was getting so close to the Earth that the edges of the globe were outside the camera's image, which accounts for the growing circular data gaps over Asia and the Pacific Ocean.

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Visualization Credits

Eric Sokolowsky (GST): Lead Animator
Greg Shirah (NASA/GSFC): Animator
Horace Mitchell (NASA/GSFC): Animator
David Chenette (LMATC): Scientist
John B. Sigwarth (University of Iowa): Scientist
Mike Carlowicz (Wyle Information Systems): Scientist
Please give credit for this item to:
NASA/Goddard Space Flight Center Scientific Visualization Studio

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Data Used:
1999/04/17 (00 49 27 UT to 04 25 05 UT)
Note: While we identify the data sets used in these visualizations, we do not store any further details nor the data sets themselves on our site.

This item is part of this series:

SVS >> Electron Fluxes
DLESE >> Geophysics
SVS >> Magnetosphere
SVS >> Solar Wind
DLESE >> Space science
SVS >> Upper Atmosphere
GCMD >> Earth Science >> Sun-earth Interactions >> Ionosphere/Magnetosphere Particles >> Aurorae
SVS >> Space Weather
SVS >> Hyperwall
SVS >> For Educators
NASA Science >> Earth
NASA Science >> Sun
GCMD >> Earth Science >> Sun-earth Interactions >> Ionosphere/Magnetosphere Dynamics >> Aurorae

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