March 31, 2001 geomagnetic storm

Auroral activity derived from POES data

by Volker Grassmann, DF5AI, May 29, 2005


Start page

data acquisition

storm history

operational results



science cooperation


Auroral activity





locating Auroras


QSO distances



The sequence of POES data files has been assembled to an animation documenting the variation of Auroral activity on March 31, 2001. The lower left polar plot displays the original POES data with the continents in fixed position (geographical alignment). Note the actual position of the red arrow indicating the direction of the sun. The panel on the right, on the other hand, shows the same data, the direction of the sun is however kept in vertical position (solar alignment), i.e. you may now watch the continents rotating during the day. The left and right panel therefore reflect an observer on Earth (observing the Auroral oval rotating relative to the Earth surface) and an observer on the sun (observing the Earth rotating underneath the Auroral oval), respectively. A detailed description of the POES data is given on the Space Environment Center (SEC) homepage, see the section How the Auroral activity patterns are created.

The upper panel displays the variable Bz component (blue) of the interplanetary magnetic field (IMF) and the actual hemispheric input power (light red), respectively. The IMF data has been shifted by about 30 minutes to consider the solar wind's travel time from the ACE spacecraft (which has taken the measurements) to the Earth's magnetosphere. The hemispheric input power (which is measured in gigawatts) is taken from the POES data plots, see the corresponding label in the lower left corner of the polar diagrams.



Copyright (C) of Volker Grassmann. All rights reserved. The material, or parts thereof, may not be reproduced in any form without prior written permission of the author.