Storm‐induced energization of radiation belt electrons: Effect of wave obliquity. Issue 16 (20th August 2013)

• Record Type: Journal Article
• Authors: Artemyev, A. V.; Agapitov, O. V.; Mourenas, D.; Krasnoselskikh, V.; Zelenyi, L. M.
• Is Part Of: Geophysical research letters. Volume 40:Issue 16(2013:Aug.)
• Page Start: 4138
• Page End: 4143
• Publication Date: 2013-08-20
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/grl.50837
• Languages: English
• ISSNs: 0094-8276

Abstract

<abstract abstract-type="main" id="grl50837-abs-0001"> <title> <x xml:space="preserve">Abstract</x> </title> <p id="grl50837-para-0001">[1] New Cluster statistics allow us to determine for the first time the variations of both the obliquity and intensity of lower‐band chorus waves as functions of latitude and geomagnetic activity near <italic>L</italic>∼5. The portion of wave power in very oblique waves decreases during highly disturbed periods, consistent with increased Landau damping by inward‐penetrating suprathermal electrons. Simple analytical considerations as well as full numerical calculations of quasi‐linear diffusion rates demonstrate that early‐time electron acceleration occurs in a regime of loss‐limited energization. In this regime, the average wave obliquity plays a critical role in mitigating lifetime reduction as wave intensity increases with geomagnetic activity, suggesting that much larger energization levels should be reached during the early recovery phase of storms than during quiet time or moderate disturbances, the latter corresponding to stronger losses. These new effects should be included in realistic radiation belt simulations.</p> </abstract>