Found 8 entries in the Bibliography.

Showing entries from 1 through 8


Rapid loss of relativistic electrons by EMIC waves in the outer radiation belt observed by Arase, Van Allen Probes, and the PWING ground stations

There has been increasing evidence for pitch angle scattering of relativistic electrons by electromagnetic ion cyclotron (EMIC) waves. Theoretical studies have predicted that the loss time scale of MeV electrons by EMIC waves can be very fast, suggesting that MeV electron fluxes rapidly decrease in association with the EMIC wave activity. This study reports on a unique event of MeV electron loss induced by EMIC waves based on Arase, Van Allen Probes, and ground-based network observations. Arase observed a signature of MeV el ...

Kurita, S.; Miyoshi, Y.; Shiokawa, K.; Higashio, N.; Mitani, T.; Takashima, T.; Matsuoka, A.; Shinohara, I.; Kletzing, C.; Blake, J.; Claudepierre, S.; Connors, M.; Oyama, S.; Nagatsuma, T.; Sakaguchi, K.; Baishev, D.; Otsuka, Y.;

YEAR: 2018     DOI: 10.1029/2018GL080262

EMIC waves; loss; PWING project; Radiation belt; The Arase satellite; Van Allen Probes


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

A multi-spacecraft event study of Pc5 ultra low frequency waves in the magnetosphere and their external drivers

We investigate a quiet-time event of magnetospheric Pc5 ultra low frequency (ULF) waves and their likely external drivers using multiple spacecraft observations. Enhancements of electric and magnetic field perturbations in two narrow frequency bands, 1.5-2 mHz and 3.5-4 mHz, were observed over a large radial distance range from r ~5 to 11 RE. During the first half of this event, perturbations were mainly observed in the transverse components and only in the 3.5-4 mHz band. In comparison, enhancements were stronger during the ...

Wang, Chih-Ping; Thorne, Richard; Liu, Terry; Hartinger, Michael; Nagai, Tsugunobu; Angelopoulos, Vassilis; Wygant, John; Breneman, Aaron; Kletzing, Craig; Reeves, Geoffrey; Claudepierre, Seth; Spence, Harlan;

YEAR: 2017     DOI: 10.1002/2016JA023610

IMF discontinuity; inner magnetosphere; Kelvin-Helmholtz vortices; magnetosheath; Pc5 waves; plasma sheet; Van Allen Probes


Prediction of MeV electron fluxes throughout the outer radiation belt using multivariate autoregressive models

The Van Allen radiation belts surrounding the Earth are filled with MeV-energy electrons. This region poses ionizing radiation risks for spacecraft that operate within it, including those in geostationary (GEO) and medium Earth orbit (MEO). To provide alerts of electron flux enhancements, sixteen prediction models of the electron log-flux variation throughout the equatorial outer radiation belt as a function of the McIlwain L parameter were developed using the multivariate autoregressive model and Kalman filter. Measurements ...

Sakaguchi, Kaori; Nagatsuma, Tsutomu; Reeves, Geoffrey; Spence, Harlan;

YEAR: 2015     DOI: 10.1002/2015SW001254

outer radiation belt; Practical prediction model; Van Allen Probes


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

Ground-based ELF/VLF chorus observations at subauroral latitudes-VLF-CHAIN Campaign

We report observations of very low frequency (VLF) and extremely low frequency (ELF) chorus waves taken during the ELF/VLF Campaign observation with High-resolution Aurora Imaging Network (VLF-CHAIN) of 17\textendash25 February 2012 at subauroral latitudes at Athabasca (L=4.3), Canada. ELF/VLF waves were measured continuously with a sampling rate of 100 kHz to monitor daily variations in ELF/VLF emissions and derive their detailed structures. We found quasiperiodic (QP) emissions whose repetition period changes rapidly withi ...

Shiokawa, Kazuo; Yokoyama, Yu; Ieda, Akimasa; Miyoshi, Yoshizumi; Nomura, Reiko; Lee, Sungeun; Sunagawa, Naoki; Miyashita, Yukinaga; Ozaki, Mitsunori; Ishizaka, Kazumasa; Yagitani, Satoshi; Kataoka, Ryuho; Tsuchiya, Fuminori; Schofield, Ian; Connors, Martin;

YEAR: 2014     DOI: 10.1002/jgra.v119.910.1002/2014JA020161

Chorus; ELF/VLF; Radiation belts; subauroral latitudes; wave-particle interactions

Cost and risk analysis of small satellite constellations for earth observation

Distributed Space Missions (DSMs) are gaining momentum in their application to Earth science missions owing to their ability to increase observation sampling in spatial, spectral, temporal and angular dimensions. Past literature from academia and industry have proposed and evaluated many cost models for spacecraft as well as methods for quantifying risk. However, there have been few comprehensive studies quantifying the cost for multiple spacecraft, for small satellites and the cost risk for the operations phase of the proje ...

Nag, Sreeja; LeMoigne, Jacqueline; de Weck, Olivier;

YEAR: 2014     DOI: 10.1109/AERO.2014.6836396

artificial satellites; risk analysis


Comparison between POES energetic electron precipitation observations and riometer absorptions: Implications for determining true precipitation fluxes

Energetic electron precipitation (EEP) impacts the chemistry of the middle atmosphere with growing evidence of coupling to surface temperatures at high latitudes. To better understand this link, it is essential to have realistic observations to properly characterize precipitation and which can be incorporated into chemistry-climate models. The Polar-orbiting Operational Environmental Satellite (POES) detectors measure precipitating particles but only integral fluxes and only in a fraction of the bounce loss cone. Ground-base ...

Rodger, Craig; Kavanagh, Andrew; Clilverd, Mark; Marple, Steve;

YEAR: 2013     DOI: 10.1002/2013JA019439

electron precipitation; POES; Radiation belts; riometery