Geophysical Research Letters

  1. Regular Articles

    1. Top of page
    2. Regular Articles
    3. Research Letters
    1. Space Sciences

      New conjunctive CubeSat and balloon measurements to quantify rapid energetic electron precipitation (pages 5833–5837)

      L. W. Blum, Q. Schiller, X. Li, R. Millan, A. Halford and L. Woodger

      Article first published online: 22 NOV 2013 | DOI: 10.1002/2013GL058546

      Key Points

      • MeV e-precipitation is measured simultaneously by CubeSat and balloons
      • Conjunctive measurements enable detailed quantification of rapid MeV e-loss
      • Precipitation bands contribute significant losses to the outer radiation belt
    2. Phase Space Density matching of relativistic electrons using the Van Allen Probes: REPT results (pages 4798–4802)

      S. K. Morley, M. G. Henderson, G. D. Reeves, R. H. W. Friedel and D. N. Baker

      Article first published online: 16 SEP 2013 | DOI: 10.1002/grl.50909

      Key Points

      • PSD matching shows TS04 model best represents inner magnetosphere configuration
      • PSD error from a model 1st adiabatic invariant is small (factor of 1.16)
      • The REPT instruments are confirmed to be well cross-calibrated
    3. Constructing the global distribution of chorus wave intensity using measurements of electrons by the POES satellites and waves by the Van Allen Probes (pages 4526–4532)

      W. Li, B. Ni, R. M. Thorne, J. Bortnik, J. C. Green, C. A. Kletzing, W. S. Kurth and G. B. Hospodarsky

      Article first published online: 12 SEP 2013 | DOI: 10.1002/grl.50920

      Key Points

      • Chorus-driven pitch angle scattering causes electron precipitation
      • Two directional electron measurement is used to infer chorus wave intensity
      • Physics-based technique provides real-time estimates on chorus wave intensity
    4. You have full text access to this OnlineOpen article
      Van Allen Probes observation of localized drift resonance between poloidal mode ultra-low frequency waves and 60 keV electrons (pages 4491–4497)

      S. G. Claudepierre, I. R. Mann, K. Takahashi, J. F. Fennell, M. K. Hudson, J. B. Blake, J. L. Roeder, J. H. Clemmons, H. E. Spence, G. D. Reeves, D. N. Baker, H. O. Funsten, R. H. W. Friedel, M. G. Henderson, C. A. Kletzing, W. S. Kurth, R. J. MacDowall, C. W. Smith and J. R. Wygant

      Article first published online: 6 SEP 2013 | DOI: 10.1002/grl.50901

      Key Points

      • First conclusive evidence of electron drift-resonance with poloidal ULF waves.
      • First to show the energy dependence to the amplitude/phase expected from theory.
      • Observation shows the drift-resonant interaction occurs over a localized region.
    5. Excitation of poloidal standing Alfvén waves through drift resonance wave-particle interaction (pages 4127–4132)

      Lei Dai, Kazue Takahashi, John R. Wygant, Liu Chen, John Bonnell, Cynthia A. Cattell, Scott Thaller, Craig Kletzing, Charles W. Smith, Robert J. MacDowall, Daniel N. Baker, J. Bernard Blake, Joseph Fennell, Seth Claudepierre, Herbert O. Funsten, Geoffrey D. Reeves and Harlan E. Spence

      Article first published online: 27 AUG 2013 | DOI: 10.1002/grl.50800

      Key Points

      • Unambiguous identification of drift-resonance in magnetosphere
      • Broad implications for ring current and ground observations
      • Drift-resonance similar to fishbone instability in Tokamak
    6. You have full text access to this OnlineOpen article
      Analysis of EMIC-wave-moderated flux limitation of measured energetic ion spectra in multispecies magnetospheric plasmas (pages 3804–3808)

      B. H. Mauk

      Article first published online: 12 AUG 2013 | DOI: 10.1002/grl.50789

      Key Points

      • A new technique determines the maximum allowed differential ion intensities
      • It predicts the sculpting of spectral shapes and consistency in peak intensities
      • Van Allen Probes mission will further test the efficacy of this new approach
    7. An unusual enhancement of low-frequency plasmaspheric hiss in the outer plasmasphere associated with substorm-injected electrons (pages 3798–3803)

      W. Li, R. M. Thorne, J. Bortnik, G. D. Reeves, C. A. Kletzing, W. S. Kurth, G. B. Hospodarsky, H. E. Spence, J. B. Blake, J. F. Fennell, S. G. Claudepierre, J. R. Wygant and S. A. Thaller

      Article first published online: 9 AUG 2013 | DOI: 10.1002/grl.50787

      Key Points

      • An unusual low-frequency hiss was observed in the dayside outer plasmaphere
      • This hiss amplification is related to injected energetic electrons
      • Electron distributions are unstable for the observed wave frequencies
    8. Evolution and slow decay of an unusual narrow ring of relativistic electrons near L ~ 3.2 following the September 2012 magnetic storm (pages 3507–3511)

      R. M. Thorne, W. Li, B. Ni, Q. Ma, J. Bortnik, D. N. Baker, H. E. Spence, G. D. Reeves, M. G. Henderson, C. A. Kletzing, W. S. Kurth, G. B. Hospodarsky, D. Turner and V. Angelopoulos

      Article first published online: 26 JUL 2013 | DOI: 10.1002/grl.50627

      Key Points

      • Relativistic electrons injected into the plasmasphere have long lifetimes
      • The loss rate is controlled by scattering by whistler-mode hiss
      • Isolated rings of relativistic electrons form during magnetic storms
  2. Research Letters

    1. Top of page
    2. Regular Articles
    3. Research Letters
    1. Space Sciences

      Van Allen Probes observations of direct wave-particle interactions (pages 1869–1875)

      J. F. Fennell, J. L. Roeder, W. S. Kurth, M. G. Henderson, B. A. Larsen, G. Hospodarsky, J. R. Wygant, J. S. G. Claudepierre, J. B. Blake, H. E. Spence, J. H. Clemmons, H. O. Funsten, C. A. Kletzing and G. D. Reeves

      Article first published online: 31 MAR 2014 | DOI: 10.1002/2013GL059165

      Key Points

      • Quasi-periodic bursts of electrons and chorus waves are simultaneous
      • Electron angular distributions change dramatically during the bursts
      • Burst electron energies are consistent with wave resonance conditions
    2. In situ observations of Pc1 pearl pulsations by the Van Allen Probes (pages 1823–1829)

      K. W. Paulson, C. W. Smith, M. R. Lessard, M. J. Engebretson, R. B. Torbert and C. A. Kletzing

      Article first published online: 17 MAR 2014 | DOI: 10.1002/2013GL059187

      Key Points

      • Pc1 pearl pulsations are found in Van Allen Probe data
      • Source region can be mapped
      • They correlate well with ground-based observations
    3. Effect of EMIC waves on relativistic and ultrarelativistic electron populations: Ground-based and Van Allen Probes observations (pages 1375–1381)

      M. E. Usanova, A. Drozdov, K. Orlova, I. R. Mann, Y. Shprits, M. T. Robertson, D. L. Turner, D. K. Milling, A. Kale, D. N. Baker, S. A. Thaller, G. D. Reeves, H. E. Spence, C. Kletzing and J. Wygant

      Article first published online: 6 MAR 2014 | DOI: 10.1002/2013GL059024

      Key Points

      • EMIC wave activity is not associated with precipitation of MeV electrons
      • EMIC waves do not deplete the ultra-relativistic belt down to 90°
      • EMIC waves cause loss of low pitch angle electrons with energies ~2–8 MeV
    4. Event-specific chorus wave and electron seed population models in DREAM3D using the Van Allen Probes (pages 1359–1366)

      Weichao Tu, G. S. Cunningham, Y. Chen, S. K. Morley, G. D. Reeves, J. B. Blake, D. N. Baker and H. Spence

      Article first published online: 5 MAR 2014 | DOI: 10.1002/2013GL058819

      Key Points

      • DREAM3D uses event-specific driving conditions measured by Van Allen Probes
      • Electron dropout is due to outward radial diffusion to compressed magnetopause
      • Event-specific chorus and seed electrons are necessary for the enhancement
    5. You have full text access to this OnlineOpen article
      Gradual diffusion and punctuated phase space density enhancements of highly relativistic electrons: Van Allen Probes observations (pages 1351–1358)

      D. N. Baker, A. N. Jaynes, X. Li, M. G. Henderson, S. G. Kanekal, G. D. Reeves, H. E. Spence, S. G. Claudepierre, J. F. Fennell, M. K. Hudson, R. M. Thorne, J. C. Foster, P. J. Erickson, D. M. Malaspina, J. R. Wygant, A. Boyd, C. A. Kletzing, A. Drozdov and Y. Y. Shprits

      Article first published online: 4 MAR 2014 | DOI: 10.1002/2013GL058942

      Key Points

      • Clear observations to higher energy than ever before
      • Precise detection of where and how acceleration takes place
      • Provides “new eyes” on megaelectron Volt
    6. Simulated magnetopause losses and Van Allen Probe flux dropouts (pages 1113–1118)

      M. K. Hudson, D. N. Baker, J. Goldstein, B. T. Kress, J. Paral, F. R. Toffoletto and M. Wiltberger

      Article first published online: 22 FEB 2014 | DOI: 10.1002/2014GL059222

      Key Points

      • Simulations of electron flux 8 Oct 2012 produce dropout into L~5.8
      • Magnetopause compression bounding the September storage ring formation modeled
      • Model shows effects of magnetopause inward motion and ULF waves on electrons
    7. The role of ring current particle injections: Global simulations and Van Allen Probes observations during 17 March 2013 storm (pages 1126–1132)

      Yiqun Yu, Vania Jordanova, Dan Welling, Brian Larsen, Seth G. Claudepierre and Craig Kletzing

      Article first published online: 22 FEB 2014 | DOI: 10.1002/2014GL059322

      Key Points

      • New capability for studying substorm-associated depolarization and injections
      • Advanced from previous technique that used artificial electromagnetic pulses
      • The model well produces injections and electron fluxes observed from Van Allen Probes
    8. You have full text access to this OnlineOpen article
      Quiet time observations of He ions in the inner magnetosphere as observed from the RBSPICE instrument aboard the Van Allen Probes mission (pages 1100–1105)

      Andrew Gerrard, Louis Lanzerotti, Matina Gkioulidou, Donald Mitchell, Jerry Manweiler and Jacob Bortnik

      Article first published online: 19 FEB 2014 | DOI: 10.1002/2013GL059175

      Key Points

      • An overview of the He-ion abundance during the first 9 months of observations
      • The appearance of a high energy, low L-shell He ion population
      • How the injected He ions respond on daily timescales
    9. Spatial localization and ducting of EMIC waves: Van Allen Probes and ground-based observations (pages 785–792)

      I. R. Mann, M. E. Usanova, K. Murphy, M. T. Robertson, D. K. Milling, A. Kale, C. Kletzing, J. Wygant, S. Thaller and T. Raita

      Article first published online: 15 FEB 2014 | DOI: 10.1002/2013GL058581

      Key Points

      • Continuous EMIC waves confined to narrow L-shells near plasma density gradients
      • The narrow L-widths explains low in-situ EMIC occurrence
      • Ground measurements provide better estimates of global EMIC wave occurrence
    10. Storm time observations of plasmasphere erosion flux in the magnetosphere and ionosphere (pages 762–768)

      J. C. Foster, P. J. Erickson, A. J. Coster, S. Thaller, J. Tao, J. R. Wygant and J. W. Bonnell

      Article first published online: 11 FEB 2014 | DOI: 10.1002/2013GL059124

      Key Points

      • High-altitude plasmasphere erosion flux has significant magnitude
      • Plasmasphere erosion flux has similar low- and high-altitude characteristics
      • Fluence of ions through cusp and midnight sector exceeds 5E25 ions s−1
    11. Global time-dependent chorus maps from low-Earth-orbit electron precipitation and Van Allen Probes data (pages 755–761)

      Yue Chen, Geoffrey D. Reeves, Reiner H. W. Friedel and Gregory S. Cunningham

      Article first published online: 7 FEB 2014 | DOI: 10.1002/2013GL059181

      Key Points

      • Demonstrate relation between chorus waves and precipitating low-energy electrons
      • Precipitating e- fluxes as quantitative proxy for global distribution of chorus
      • LEO e- observation has new significance for space weather monitoring/modeling
    12. An empirically observed pitch-angle diffusion eigenmode in the Earth's electron belt near L* = 5.0 (pages 251–258)

      T. P. O'Brien, S. G. Claudepierre, J. B. Blake, J. F. Fennell, J. H. Clemmons, J. L. Roeder, H. E. Spence, G. D. Reeves and D. N. Baker

      Article first published online: 27 JAN 2014 | DOI: 10.1002/2013GL058713

      Key Points

      • We observe a pure eigenmode of pitch angle diffusion in the radiation belt
      • The eigenmode is characterized by synchronized decay at all pitch angles
      • From the eigenmode, we derive a hypothetical pitch angle diffusion coefficient
    13. Nonstorm time dynamics of electron radiation belts observed by the Van Allen Probes (pages 229–235)

      Zhenpeng Su, Fuliang Xiao, Huinan Zheng, Zhaoguo He, Hui Zhu, Min Zhang, Chao Shen, Yuming Wang, Shui Wang, C. A. Kletzing, W. S. Kurth, G. B. Hospodarsky, H. E. Spence, G. D. Reeves, H. O. Funsten, J. B. Blake and D. N. Baker

      Article first published online: 22 JAN 2014 | DOI: 10.1002/2013GL058912

      Key Points

      • A rarely reported nonstorm time event of RB reformation observed by RBSP
      • Formation of a new belt near the outer boundary of the original outer belt
      • Importance of chorus-driven local acceleration: observation and simulation
    14. Chorus waves and spacecraft potential fluctuations: Evidence for wave-enhanced photoelectron escape (pages 236–243)

      D. M. Malaspina, R. E. Ergun, A. Sturner, J. R. Wygant, J. W. Bonnell, A. Breneman and K. Kersten

      Article first published online: 22 JAN 2014 | DOI: 10.1002/2013GL058769

      Key Points

      • Spacecraft potential fluctuations during chorus waves are not caused by density
      • Photoelectron escape due to natural electric fields drives spacecraft potential
      • Prior works may need to be reexamined based on these results
    15. Observations of kinetic scale field line resonances (pages 209–215)

      Christopher C. Chaston, John W. Bonnell, John R. Wygant, Forrest Mozer, Stuart D. Bale, Kris Kersten, Aaron W. Breneman, Craig A. Kletzing, William S. Kurth, George B. Hospodarsky, Charles W. Smith and Elizabeth A. MacDonald

      Article first published online: 21 JAN 2014 | DOI: 10.1002/2013GL058507

      Key Points

      • Injections contain kinetic scale field-line resonances
      • kinetic scale field-line resonances allow ion energisation
      • May contribute to the heavy ion ring current
    16. Fine structure of large-amplitude chorus wave packets (pages 293–299)

      O. Santolík, C. A. Kletzing, W. S. Kurth, G. B. Hospodarsky and S. R. Bounds

      Article first published online: 16 JAN 2014 | DOI: 10.1002/2013GL058889

      Key Points

      • Direct 3-D measurements of the magnetic field of intense chorus subpackets
      • First detection of variations of the wave vector direction within subpackets
      • Wave vector angles are anticorrelated with the logarithm of peak amplitudes
    17. A nonstorm time enhancement of relativistic electrons in the outer radiation belt (pages 7–12)

      Quintin Schiller, Xinlin Li, Lauren Blum, Weichao Tu, Drew L. Turner and J. B. Blake

      Article first published online: 15 JAN 2014 | DOI: 10.1002/2013GL058485

      Key Points

      • Extreme relativistic electron enhancements do not require a geomagnetic storm
      • This enhancement is caused by internal acceleration and rapid radial transport
      • Conjunctive measurements are required to better understand system dynamics
    18. Prompt energization of relativistic and highly relativistic electrons during a substorm interval: Van Allen Probes observations (pages 20–25)

      J. C. Foster, P. J. Erickson, D. N. Baker, S. G. Claudepierre, C. A. Kletzing, W. Kurth, G. D. Reeves, S. A. Thaller, H. E. Spence, Y. Y. Shprits and J. R. Wygant

      Article first published online: 15 JAN 2014 | DOI: 10.1002/2013GL058438

      Key Points

      • Substorm dynamics are important for highly relativistic electron energization
      • Cold plasma preconditioning is significant for rapid relativistic energization
      • Relativistic / highly relativistic electron energization can occur in < 5 hrs