Low-altitude measurements of 2–6 MeV electron trapping lifetimes at 1.5 ≤ L ≤ 2.5

During the Halloween Storm period (October–November 2003), a new Van Allen belt electron population was powerfully accelerated. The inner belt of electrons formed in this process decayed over a period of days to years. We have examined quantitatively the decay rates for electrons seen in the region of 1.5 ≤ L ≤ 2.5 using SAMPEX satellite observations. At L = 1.5 the e-folding lifetime for 2–6 MeV electrons was τ ∼ 180 days. On the other hand, for the half-dozen distinct acceleration (or enhancement) events seen during late-2003 through 2005 at L ∼ 2.0, the lifetimes ranged from τ ∼ 8 days to τ ∼ 35 days. We compare these loss rates to those expected from prior studies. We find that lifetimes at L = 2.0 are much shorter than the average 100–200 days that present theoretical estimates would suggest for the overall L = 2 electron population. Additional wave-particle interaction aspects must be included in theoretical treatments and we describe such possibilities here.

Details

Publication status:
Published
Author(s):
Authors: Baker, D.N., Kanekal, S.G., Horne, R.B. ORCIDORCID record for R.B. Horne, Meredith, N.P. ORCIDORCID record for N.P. Meredith, Glauert, S.A. ORCIDORCID record for S.A. Glauert

On this site: Nigel Meredith, Richard Horne, Sarah Glauert
Date:
1 January, 2007
Journal/Source:
Geophysical Research Letters / 34
Page(s):
5pp
Digital Object Identifier (DOI):
https://doi.org/10.1029/2007GL031007