Found 9 entries in the Bibliography.

Showing entries from 1 through 9


Generation of EMIC Waves and Effects on Particle Precipitation During a Solar Wind Pressure Intensification with B z >

During geomagnetic storms, some fraction of the solar wind energy is coupled via reconnection at the dayside magnetopause, a process that requires a southward interplanetary magnetic field Bz. Through a complex sequence of events, some of this energy ultimately drives the generation of electromagnetic ion cyclotron (EMIC) waves, which can then scatter energetic electrons and ions from the radiation belts. In the event described in this paper, the interplanetary magnetic field remained northward throughout the event, a condit ...

Lessard, Marc; Paulson, Kristoff; Spence, Harlan; Weaver, Carol; Engebretson, Mark; Millan, Robyn; Woodger, Leslie; Halford, Alexa; Horne, Richard; Rodger, Craig; Hendry, Aaron;

YEAR: 2019     DOI: 10.1029/2019JA026477

Van Allen Probes


MMS, Van Allen Probes, GOES 13, and Ground Based Magnetometer Observations of EMIC Wave Events Before, During, and After a Modest Interplanetary Shock

The stimulation of EMIC waves by a magnetospheric compression is perhaps the closest thing to a controlled experiment that is currently possible in magnetospheric physics, in that one prominent factor that can increase wave growth acts at a well-defined time. We present a detailed analysis of EMIC waves observed in the outer dayside magnetosphere by the four Magnetosphere Multiscale (MMS) spacecraft, Van Allen Probe A, and GOES 13, and by four very high latitude ground magnetometer stations in the western hemisphere before, ...

Engebretson, M.; Posch, J.; Capman, N.; Campuzano, N.; elik, P.; Allen, R.; Vines, S.; Anderson, B.; Tian, S.; Cattell, C.; Wygant, J.; Fuselier, S.; Argall, M.; Lessard, M.; Torbert, R.; Moldwin, M.; Hartinger, M.; Kim, H.; Russell, C.; Kletzing, C.; Reeves, G.; Singer, H.;

YEAR: 2018     DOI: 10.1029/2018JA025984

Van Allen Probes

EMIC wave events during the four GEM QARBM challenge intervals

This paper presents observations of EMIC waves from multiple data sources during the four GEM challenge events in 2013 selected by the GEM \textquotedblleftQuantitative Assessment of Radiation Belt Modeling\textquotedblright focus group: March 17-18 (Stormtime Enhancement), May 31-June 2 (Stormtime Dropout), September 19-20 (Non-storm Enhancement), and September 23-25 (Non-storm Dropout). Observations include EMIC wave data from the Van Allen Probes, GOES, and THEMIS spacecraft in the near-equatorial magnetosphere and from s ...

Engebretson, M.; Posch, J.; Braun, D.; Li, W.; Ma, Q.; Kellerman, A.; Huang, C.-L.; Kanekal, S.; Kletzing, C.; Wygant, J.; Spence, H.; Baker, D.; Fennell, J.; Angelopoulos, V.; Singer, H.; Lessard, M.; Horne, R.; Raita, T.; Shiokawa, K.; Rakhmatulin, R.; Dmitriev, E.; Ermakova, E.;

YEAR: 2018     DOI: 10.1029/2018JA025505

Van Allen Probes


In situ statistical observations of Pc1 pearl pulsations and unstructured EMIC waves by the Van Allen Probes

We present here the first in situ statistical survey of structured Pc1 pearl pulsations compared with unstructured electromagnetic ion cyclotron (EMIC) waves observed by the Van Allen Probes spacecraft. This data set was compiled from observations spanning 8 September 2012 through 31 August 2015 and comprises over 1630 h of total EMIC wave activity, of which 291 h exhibited pearl structure. Additionally, we have identified 29 wave events demonstrating periodically oscillating wave packets, mostly about the magnetic equator, ...

Paulson, K.; Smith, C.; Lessard, M.; Torbert, R.; Kletzing, C.; Wygant, J.;

YEAR: 2016     DOI: 10.1002/2016JA023160

EMIC waves; Pc1 pearl pulsations; Van Allen Probes


Correlated Pc4-5 ULF waves, whistler-mode chorus and pulsating aurora observed by the Van Allen Probes and ground-based systems

Theory and observations have linked equatorial VLF waves with pulsating aurora for decades, invoking the process of pitch-angle scattering of 10\textquoterights keV electrons in the equatorial magnetosphere. Recently published satellite studies have strengthened this argument, by showing strong correlation between pulsating auroral patches and both lower-band chorus and 10\textquoterights keV electron modulation in the vicinity of geosynchronous orbit. Additionally, a previous link has been made between Pc4-5 compressional p ...

Jaynes, A.; Lessard, M.; Takahashi, K.; Ali, A.; Malaspina, D.; Michell, R.; Spanswick, E.; Baker, D.; Blake, J.; Cully, C.; Donovan, E.; Kletzing, C.; Reeves, G.; Samara, M.; Spence, H.; Wygant, J.;

YEAR: 2015     DOI: 10.1002/2015JA021380

aurora; precipitation; pulsating aurora; substorms; ULF waves; Van Allen Probes; VLF waves

Van Allen probes, NOAA, GOES, and ground observations of an intense EMIC wave event extending over 12 hours in MLT

Although most studies of the effects of EMIC waves on Earth\textquoterights outer radiation belt have focused on events in the afternoon sector in the outer plasmasphere or plume region, strong magnetospheric compressions provide an additional stimulus for EMIC wave generation across a large range of local times and L shells. We present here observations of the effects of a wave event on February 23, 2014 that extended over 8 hours in UT and over 12 hours in local time, stimulated by a gradual 4-hour rise and subsequent shar ...

Engebretson, M.; Posch, J.; Wygant, J.; Kletzing, C.; Lessard, M.; Huang, C.-L.; Spence, H.; Smith, C.; Singer, H.; Omura, Y.; Horne, R.; Reeves, G.; Baker, D.; Gkioulidou, M.; Oksavik, K.; Mann, I.; Raita, T; Shiokawa, K.;

YEAR: 2015     DOI: 10.1002/2015JA021227

EMIC waves; magnetospheric compressions; Radiation belts; Van Allen Probes

Solar cycle dependence of ion cyclotron wave frequencies

Electromagnetic ion cyclotron (EMIC) waves have been studied for decades, though remain a fundamentally important topic in heliospheric physics. The connection of EMIC waves to the scattering of energetic particles from Earth\textquoterights radiation belts is one ofmany topics that motivate the need for a deeper understanding of characteristics and occurrence distributions of the waves. In this study, we show that EMIC wave frequencies, as observed at Halley Station in Antarctica from 2008 through 2012, increase by approxim ...

Lessard, Marc; Lindgren, Erik; Engebretson, Mark; Weaver, Carol;

YEAR: 2015     DOI: 10.1002/2014JA020791

EMIC waves; Ion cyclotron; Magnetosphere; plasma waves; Radiation belts; solar cycles

Electron precipitation from EMIC waves: a case study from 31 May 2013

On 31 May 2013 several rising-tone electromagnetic ion-cyclotron (EMIC) waves with intervals of pulsations of diminishing periods (IPDP) were observed in the magnetic local time afternoon and evening sectors during the onset of a moderate/large geomagnetic storm. The waves were sequentially observed in Finland, Antarctica, and western Canada. Co-incident electron precipitation by a network of ground-based Antarctic Arctic Radiation-belt Dynamic Deposition VLF Atmospheric Research Konsortia (AARDDVARK) and riometer instrument ...

Clilverd, Mark; Duthie, Roger; Hardman, Rachael; Hendry, Aaron; Rodger, Craig; Raita, Tero; Engebretson, Mark; Lessard, Marc; Danskin, Donald; Milling, David;

YEAR: 2015     DOI: 10.1002/2015JA021090

electromagnetic ion-cyclotron; electron precipitation; radio propagation; satellite


In situ observations of Pc1 pearl pulsations by the Van Allen Probes

We present in situ observations of Pc1 pearl pulsations using the Van Allen Probes. These waves are often observed using ground-based magnetometers, but are rarely observed by orbiting satellites. With the Van Allen Probes, we have seen at least 14 different pearl pulsation events during the first year of operations. These new in situ measurements allow us to identify the wave classification based on local magnetic field conditions. Additionally, by using two spacecraft, we are able to observe temporal changes in the region ...

Paulson, K.; Smith, C.; Lessard, M.; Engebretson, M.; Torbert, R.; Kletzing, C.;

YEAR: 2014     DOI: 10.1002/2013GL059187

Van Allen Probes