1. Laboratory for Atmospheric and Space Physics, University of Colorado, 1234 Innovation Drive, Boulder, Colorado 80303-7814, USA
2. Southwest Research Institute, PO Drawer 28510, San Antonio, Texas 78284, USA

Correspondence to: D. N. Baker¹ Email: daniel.baker@lasp.colorado.edu

Abstract

The Earth's radiation belts—also known as the Van Allen belts¹—contain high-energy electrons trapped on magnetic field lines^{2, 3}. The centre of the outer belt is usually 20,000–25,000 km from Earth. The region between the belts is normally devoid of particles^{2, 3, 4}, and is accordingly favoured as a location for spacecraft operation because of the benign environment⁵. Here we report that the outer Van Allen belt was compressed dramatically by a solar storm known as the 'Hallowe'en storm' of 2003. From 1 to 10 November, the outer belt had its centre only 10,000 km from Earth's equatorial surface, and the plasmasphere was similarly displaced inwards. The region between the belts became the location of high particle radiation intensity. This remarkable deformation of the entire magnetosphere implies surprisingly powerful acceleration and loss processes deep within the magnetosphere.

MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.