Relativistic electron dynamics during geomagnetic storms: energization, loss and global coherence
ROSES ID: NNH06ZDA001N Selection Year: 2007
Program Element: Independent Investigation
Principal Investigator: Shri Kanekal
Affiliation(s): University of Colorado
Project Member(s):
Fennell, Joseph F. Co-I Aerospace Corp.
Baker, Daniel N Collaborator University of Colorado, Boulder
O'Brien, Thomas Paul Collaborator The Aerospace Corporation
Summary:
The aim of our proposed research is to understand the physics of acceleration,
transport and loss of electrons in the Earth's outer radiation belt during
geomagnetic storms. Specifically we propose to (i) quantify electron flux
dynamics during geomagnetic storms over an entire solar cycle across all L
shells, (ii) characterize global coherence emphasizing pitch-angle scattering
leading to flux isotropization, and (iii) investigate the systematics of
electron decay time-scales and the specific role of electron microbursts as a
loss mechanism.
The results of our investigations will help determine the relative strengths of
particle transport versus in-situ processes in electron energization. We will
quantify the role of flux isotropization, i.e, pitch-angle scaterring during
electron acceleration. Our results of electron decay times will help distinguish
between various mechansism of pitch angle scattering leading to electron loss.
We will also quantify the extent to which microbursts result in the depeletion of electron flux.
Our research will utilize observations made by multiple spacecraft including
SAMPEX, Polar and HEO which provide a comprehensive coverage of the Earth's
outer radiation belt. Our database covers an entire solar cycle and comprises
measurements of electrons over a wide energy range. These spacecraft are in
distinct orbits around the Earth and therefore provide a global picture of the outer zone.
Our proposed research directly addresses two major objectives of the LWS
program:(a) to identify and understand response of the space environment to
solar variability, and (b) to quantitatively connect this response to solar
variability. A major objective of the TR\&T program is to understand the
acceleration, transport and loss of radiation belt particles. Space
environmental conditions affecting robotic and human exploration include the
Earth's Radiation belts. Our proposed research is therefore highly
relevant to the LWS and especially the TR\&T program.
Presentations:
| Performance Year | Reference | Actions |
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| 1 | Johnston, W. R.; Anderson, P. C.; Goldstein, J.; O&#...
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| 1 | Kanekal, Shrikanth; Fennell, J. F.; Baker, Daniel N.;...
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| 1 | Baker, D. N.; Kanekal, S. G.; (2011), Studying changes ...
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| 1 | Kanekal, Shrikanth; Elkington, Scot; (2012), Coupling emp...
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| 1 | Hoxie, V. C.; Baker, D. N.; Kanekal, S. G.; Spence,...
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