Characteristic Signatures of Radial or Local Acceleration of Electron inside Earth Radiation Belt

Asif Ali Abbasi, Muhammad Shahid Qureshi, Zahida Ehsan


Radiation belt science has several enigmatic issues among which is yet unexplained electron acceleration in the million electron Volt (MeV) energy range. An extensive data set of Relativistic Electron-Proton Tele-scope (REPT) on board the Radiation Belt Storm Probe (RBSP) is studied for the 28 June, 2013 electron acceleration event. Phase space density is first determined for 2.30 MeV particles from measured integral flux and then calculated for the appropriate energy that conserves the first adiabatic invariant. It is shown that the time dependent radial profile of phase space density supports the local acceleration mechanism.


Electron Acceleration; Phase Space Density; Local Peak

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Baker DN, Kanekal SG, Hoxie VC, Batiste S, Bolton M, Li X, Elkington SR, Monk S, Reukauf R, Steg

S, Westfall J, Belting C, Bolton B, Braun D, Cervelli B, Hubbell K, Kien M, Knappmiller S, Wade S,

Lamprecht B, Stevens K, Wallace J, Yehle A, Spence H E, Friede R. (2013). The Relativistic

Electron-Proton Telescope (REPT) Instrument on Board the Radiation Belt Storm Probes (RBSP)

Spacecraft: Characterization of Earth’s Radiation Belt High-Energy Particle Populations. Space

Science Reviews 179(1–4):337–381.

Baker DN, Kanekal SG, Hoxie VC, Henderson MG, Li X, Spence HE, Elkington SR, Friedel RHW,

Goldstein J, Hudson MK, Reeves GD, Thorne RM, Kletzing CA, Claudepierre SG. (2013). A long-lived

relativistic electron storage ring embedded in Earth’s outer Van Allen belt. Science 340(6129):186-190.

Chen Y, Friedel RH, Reeves GD, Cayton, TE, Christensen R. (2007). Multisatellite determination of

the relativistic electron phase space density at geosynchronous orbit: An integrated investigation

during geomagnetic storm times. Journal of Geophysical Research: Space Physics 112(A11).

Chen Y, Reeves GD, Friedel RH. (2007). The energization of relativistic electrons in the outer Van

Allen radiation belt. Nature Physics 3(9):614.

Chen Y, Reeves GD, Friedel RHW. (2007). The energization of relativistic electrons in the outer Van

Allen radiation belt. Nature Physics 3:614–617.

Hilmer RV, Ginet GP, Cayton TE. Enhancement of equatorial energetic electron fluxes near L=4.2 as

a result of high speed solar wind streams. Journal of Geophysical Research: Space Physics 105(A10).

Mauk BH, Fox NJ, Kanekal SG, Kessel RL, Sibeck DG, Ukhorskiy A. (2013). Science objectives and

rationale for the radiation belt storm probes mission. Space Science Reviews 179(1–4): 3–27.

McAdams KL, Reeves GD, Friedel RH, Cayton TE. (2001). Multisatellite comparisons of the radiation

belt response to the Geospace Environment Modeling (GEM) magnetic storms. Journal of

Geophysical Research 106(A6): 10,869.

Morley S, Henderson MG, Reeves GD, Friedel RHW, Baker DN. (2013). Phase space density

matching of relativistic electrons using the Van Allen Probes: REPT results. Geophys. Res. Lett. 40:


Reeves GD, Spence HE, Henderson MG, Morley SK, Friedel RHW, Funsten HO, Baker DN, Kanekal

SG, Blake JB, Fennell JF, Claudepierre SG, Thorne RM, Turner DL, Kletzing CA, Kurth WS, Larsen

BA, Niehof JT. (2013). Electron Acceleration in the Heart of the Van Allen Radiation Belts. Science


Roederer JG. (1970). Dynamics of Geomagnetically Trapped Radiation. Springer, New York. Pp 1-139.

Selesnick RS, Blake JB, Kolasinski WA, Fritz TA. (1997). A quiescent state of 3 to 8 MeV radiation belt

electrons. Geophysical Research Letters 24(11): 1343-1346.

Selesnick RS, Blake JB. (1997). Dynamics of the outer radiation belt. Geophysical research letters

(11): 1347-1350.

Selesnick RS, Blake JB. (1998). Radiation belt electron observations following the January 1997

magnetic cloud event. Geophysical research letters 25(14): 2553-2556.

Selesnick RS, Blake JB. (2000). On the source location of radiation belt relativistic electrons. Journal

of Geophysical Research: Space Physics 105(A2):2607-2624.

Tu W, Li X, Chen Y, Reeves GD, Temerin M. (2009). Stormdependent

radiation belt electron dynamics.

Journal of Geophysical Research: Space Physics 114(A2): 2156–2202.

Turner DL, Shprits Y, Hartinger M, Angelopoulos V. (2012). Explaining sudden losses of outer radiation

belt electrons during geomagnetic storms. Nature Physics 8(3): 208–212.

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