Found 9 entries in the Bibliography.
Showing entries from 1 through 9
2019 |
Energy coupling between the solar wind and the Earth\textquoterights magnetosphere can affect the electron population in the outer radiation belt. However, the precise role of different internal and external mechanisms that leads to changes of the relativistic electron population is not entirely known. This paper describes how Ultra Low Frequency (ULF) wave activity during the passage of Alfv\ enic solar wind streams contributes to the global recovery of the relativistic electron population in the outer radiation belt. To in ... Da Silva, L.; Sibeck, D.; Alves, L.; Souza, V.; Jauer, P.; Claudepierre, S.; Marchezi, J.; Agapitov, O.; Medeiros, C.; Vieira, L.; Wang, C.; Jiankui, S.; Liu, Z.; Gonzalez, W.; Dal Lago, A.; Rockenbach, M.; Padua, M.; Alves, M.; Barbosa, M.; Fok, M.-C.; Baker, D.; Kletzing, C.; Kanekal, S.; Georgiou, M.; YEAR: 2019   DOI: 10.1029/2018JA026184 alfv\ en fluctuations; Earth\textquoterights magnetosphere; high speed stream; Radiation belts; relativistic electron flux; ULF wave; Van Allen Probes |
Initial Results From the GEM Challenge on the Spacecraft Surface Charging Environment Spacecraft surface charging during geomagnetically disturbed times is one of the most important causes of satellite anomalies. Predicting the surface charging environment is one prevalent task of the geospace environment models. Therefore, the Geospace Environment Modeling (GEM) Focus Group \textquotedblleftInner Magnetosphere Cross-energy/Population Interactions\textquotedblright initiated a community-wide challenge study to assess the capability of several inner magnetosphere ring current models in determining surface char ... Yu, Yiqun; ätter, Lutz; Jordanova, Vania; Zheng, Yihua; Engel, Miles; Fok, Mei-Ching; Kuznetsova, Maria; YEAR: 2019   DOI: 10.1029/2018SW002031 GEM challenge; IMCEPI Focus Group; ring current model assessment; Space weather; spacecraft surface charging; Van Allen Probes |
2018 |
An energetic electron flux dropout due to magnetopause shadowing on 1 June 2013 We examine the mechanisms responsible for the dropout of energetic electron flux during 31 May \textendash 1 June 2013, using Van Allen Probe (RBSP) electron flux data and simulations with the Comprehensive Inner Magnetosphere-Ionosphere (CIMI) model. During storm main phase, L-shells at RBSP locations are greater than ~ 8, which are connected to open drift shells. Consequently, diminished electron fluxes were observed over a wide range of energies. The combination of drift shell splitting, magnetopause shadowing and drift l ... Bin Kang, Suk-; Fok, Mei-Ching; Komar, Colin; Glocer, Alex; Li, Wen; Buzulukova, Natalia; YEAR: 2018   DOI: 10.1002/2017JA024879 CIMI model; drift loss; dropout; magnetopause shadowing; pitch-angle distribution (PAD); RBSP; Van Allen Probes |
2017 |
CIMI simulations with newly developed multi-parameter chorus and plasmaspheric hiss wave models Numerical simulation studies of the Earth\textquoterights radiation belts are important to understand the acceleration and loss of energetic electrons. The Comprehensive Inner Magnetosphere-Ionosphere (CIMI) model considers the effects of the ring current and plasmasphere on the radiation belts to obtain plausible results. The CIMI model incorporates pitch angle, energy, and cross diffusion of electrons, due to chorus and plasmaspheric hiss waves. These parameters are calculated using statistical wave distribution models of ... Aryan, Homayon; Sibeck, David; Bin Kang, Suk-; Balikhin, Michael; Fok, Mei-Ching; Agapitov, Oleksiy; Komar, Colin; Kanekal, Shrikanth; Nagai, Tsugunobu; YEAR: 2017   DOI: 10.1002/2017JA024159 Chorus and plasmaspheric hiss wave models; CIMI numerical simulations; Geomagnetic storm events; Radiation belt electron flux enhancements; Van Allen Probes; VLF waves; Wave-particle interaction |
2016 |
Determination of the Earth\textquoterights plasmapause location from the CE-3 EUVC images The Moon-based Extreme Ultraviolet Camera (EUVC) aboard China\textquoterights Chang\textquoterighte-3 (CE-3) mission has successfully imaged the entire Earth\textquoterights plasmasphere for the first time from the side views on lunar surface. An EUVC image on 21 April 2014 is used in this study to demonstrate the characteristics and configurations of the Moon-based EUV imaging and to illustrate the determination algorithm of the plasmapause locations on the magnetic equator. The plasmapause locations determined from all the ... He, Fei; Zhang, Xiao-Xin; Chen, Bo; Fok, Mei-Ching; YEAR: 2016   DOI: 10.1002/2015JA021863 Chang\textquoterighte-3; EUV imaging; Plasmapause; plasmasphere; reconstruction |
2015 |
Electromagnetic ion cyclotron (EMIC) waves are closely related to precipitating loss of relativistic electrons in the radiation belts, and thereby, a model of the radiation belts requires inclusion of the pitch angle diffusion caused by EMIC waves. We estimated the pitch angle diffusion rates and the corresponding precipitation time scales caused by H and He band EMIC waves using the Tsyganenko 04 (T04) magnetic field model at their probable regions in terms of geomagnetic conditions. The results correspond to enhanced pitch ... Bin Kang, Suk-; Min, Kyoung-Wook; Fok, Mei-Ching; Hwang, Junga; Choi, Cheong-Rim; YEAR: 2015   DOI: 10.1002/2014JA020644 EMIC waves; pitch angle diffusion rate; precipitation time scale; quasi-linear theory; realistic field model; Relativistic electron |
We investigate an electron flux dropout during a weak storm on 7\textendash8 November 2008, with Dst minimum value being -37 nT. During this period, two clear dropouts were observed on GOES 11 > 2 MeV electrons. We also find a simultaneous dropout in the subrelativistic electrons recorded by Time History of Events and Macroscale Interactions during Substorms probes in the outer radiation belt. Using the Radiation Belt Environment model, we try to reproduce the observed dropout features in both relativistic and subrelativisti ... Hwang, J.; Choi, E.-J.; Park, J.-S.; Fok, M.-C.; Lee, D.-Y.; Kim, K.-C.; Shin, D.-K.; Usanova, M.; Reeves, G.; YEAR: 2015   DOI: 10.1002/2015JA021085 atmospheric precipitation; flux dropout; Geomagnetic storm; magneopause shadowing; Radiation belt; RBE model |
The global context of the 14 November, 2012 storm event From 2 to 5 UT on 14 November, 2012, the Van Allen Probes observed repeated particle flux dropouts during the main phase of a geomagnetic storm as the satellites traversed the post-midnight to dawnside inner magnetosphere. Each flux dropout corresponded to an abrupt change in the magnetic topology, i.e., from a more dipolar configuration to a configuration with magnetic field lines stretched in the dawn-dusk direction. Geosynchronous GOES spacecraft located in the dusk and near-midnight sectors and the LANL constellation wit ... Hwang, K.-J.; Sibeck, D.; Fok, M.-C.; Zheng, Y.; Nishimura, Y.; Lee, J.-J.; Glocer, A.; Partamies, N.; Singer, H.; Reeves, G.; Mitchell, D.; Kletzing, C.; Onsager, T.; YEAR: 2015   DOI: 10.1002/2014JA020826 |
2014 |
The Comprehensive Inner Magnetosphere-Ionosphere Model Simulation studies of the Earth\textquoterights radiation belts and ring current are very useful in understanding the acceleration, transport, and loss of energetic particles. Recently, the Comprehensive Ring Current Model (CRCM) and the Radiation Belt Environment (RBE) model were merged to form a Comprehensive Inner Magnetosphere-Ionosphere (CIMI) model. CIMI solves for many essential quantities in the inner magnetosphere, including ion and electron distributions in the ring current and radiation belts, plasmaspheric densit ... Fok, M.-C.; . Y. Buzulukova, N; Chen, S.-H.; Glocer, A.; Nagai, T.; Valek, P.; Perez, J.; YEAR: 2014   DOI: 10.1002/jgra.v119.910.1002/2014JA020239 inner magnetosphere; magnetosphere-ionosphere coupling; ring current; Radiation belts; Van Allen Probes |
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