Initial results from the coupled magnetosphere ionosphere thermosphere model: magnetospheric and ionospheric responses

Wiltberger, M. J.; Wang, Wenbin; Burns, A. G.; Solomon, Stanley C.; Lyon, J. G.; Goodrich, C. C.

doi:10.1016/j.jastp.2004.03.026

Cited by 158 publications

(152 citation statements)

References 37 publications

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“…He found that a reduction in the magnetic dipole moment causes an increase in the Sq current intensity because the effect of enhanced ionospheric conductivities overcomes the effect due to the reduction in the U × B field. Cnossen and Richmond (2013), using the Coupled Magnetosphere-IonosphereThermosphere (CMIT) model (Wiltberger et al 2004 Increasing concentrations of CO 2 in the lower atmosphere are expected to cool the middle and upper atmosphere, where CO 2 acts as an effective radiative coolant. This leads to further changes in the densities and compositions in the thermosphere and ionosphere (Cnossen 2012;Laštovička et al 2012), which can affect the ionospheric conductivities.…”

Section: Long-term Variationmentioning

confidence: 99%

Sq and EEJ—A Review on the Daily Variation of the Geomagnetic Field Caused by Ionospheric Dynamo Currents

2016

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A record of the geomagnetic field on the ground sometimes shows smooth daily variations on the order of a few tens of nano teslas. These daily variations, commonly known as Sq, are caused by electric currents of several μA/m 2 flowing on the sunlit side of the Eregion ionosphere at about 90-150 km heights. We review advances in our understanding of the geomagnetic daily variation and its source ionospheric currents during the past 75 years. Observations and existing theories are first outlined as background knowledge for the nonspecialist. Data analysis methods, such as spherical harmonic analysis, are then described in detail. Various aspects of the geomagnetic daily variation are discussed and interpreted using these results. Finally, remaining issues are highlighted to provide possible directions for future work.

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Section: Long-term Variationmentioning

confidence: 99%

Sq and EEJ—A Review on the Daily Variation of the Geomagnetic Field Caused by Ionospheric Dynamo Currents

2016

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“…In this study, we use the global Lyon-FedderMobarry (LFM) MHD model described in detail by Lyon et al (2004). LFM is coupled with two other models which improve description of physical processes in the inner magnetosphere.…”

Section: Mhd Modelmentioning

confidence: 99%

Magnetohydrodynamic modeling of three Van Allen Probes storms in 2012 and 2013

et al. 2015

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Abstract. Coronal mass ejection (CME)-shock compression of the dayside magnetopause has been observed to cause both prompt enhancement of radiation belt electron flux due to inward radial transport of electrons conserving their first adiabatic invariant and prompt losses which at times entirely eliminate the outer zone. Recent numerical studies suggest that enhanced ultra-low frequency (ULF) wave activity is necessary to explain electron losses deeper inside the magnetosphere than magnetopause incursion following CME-shock arrival. A combination of radial transport and magnetopause shadowing can account for losses observed at radial distances into L = 4.5, well within the computed magnetopause location. We compare ULF wave power from the Electric Field and Waves (EFW) electric field instrument on the Van Allen Probes for the 8 October 2013 storm with ULF wave power simulated using the Lyon-FedderMobarry (LFM) global magnetohydrodynamic (MHD) magnetospheric simulation code coupled to the Rice Convection Model (RCM). Two other storms with strong magnetopause compression, 8-9 October 2012 and 17-18 March 2013, are also examined. We show that the global MHD model captures the azimuthal magnetosonic impulse propagation speed and amplitude observed by the Van Allen Probes which is responsible for prompt acceleration at MeV energies reported for the 8 October 2013 storm. The simulation also captures the ULF wave power in the azimuthal component of the electric field, responsible for acceleration and radial transport of electrons, at frequencies comparable to the electron drift period. This electric field impulse has been shown to explain observations in related studies (Foster et al., 2015) of electron acceleration and drift phase bunching by the Energetic Particle, Composition, and Thermal Plasma Suite (ECT) instrument on the Van Allen Probes.

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“…A detailed description of the CMIT model can be found in Luhmann et al (2004), Wiltberger et al (2004. In short, the CMIT model couples the Lyon-Fedder-Mobarry (LFM) global magnetosphere MHD code (Lyon, Fedder, and Mobarry, 2004) with the Thermosphere Ionosphere Electrodynamics General Circulation Model (TIEGCM) (Richmond, Ridley, and Roble, 1992).…”

Section: Model Simulationsmentioning

confidence: 99%

Ionospheric Day-to-Day Variability Around the Whole Heliosphere Interval in 2008

et al. 2011

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Ionospheric F2 peak electron densities (NmF2) measured at ten ionosonde stations have been analyzed to investigate ionospheric day-to-day variability around the Whole Heliosphere Interval (WHI) in 2008 (Day of Year (DOY) 50 -140). The ionosonde data showed that there was significant global day-to-day variability in NmF2. This variability had 5-, 7-, 9-, 11-, 13.5-, and 16 -21-day periodicities. At middle latitudes, the ionosphere appeared to respond directly to the solar-wind and interplanetary-magnetic-field (IMF) induced geomagnetic-activity forcing, with the day-to-day variability having the same periods as those in the solar-wind/IMF and geomagnetic activity. At the geomagnetic Equator, the ionosphere had a strong 7-day periodicity, corresponding to the same periodicity in the IMF B z component. In the equatorial anomaly region, the ionosphere showed more complicated day-to-day variability, dominated by the 9-day periodicity. In addition, there were also peri- odicities of 11 days and 16 -21 days in the ionosonde data at some stations. The ionosonde data were compared with the Coupled Magnetosphere Ionosphere Thermosphere (CMIT) simulations that were driven by the observed solar-wind and IMF data during the WHI. The CMIT simulations showed similar ionospheric daily variability seen in the data. They captured the positive and negative responses of the ionosphere at middle latitudes during the first corotating interaction region (CIR) event in the WHI. The response of the model to the second CIR event, however, was relatively weak.

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Initial results from the coupled magnetosphere ionosphere thermosphere model: magnetospheric and ionospheric responses

Cited by 158 publications

References 37 publications

Sq and EEJ—A Review on the Daily Variation of the Geomagnetic Field Caused by Ionospheric Dynamo Currents

Sq and EEJ—A Review on the Daily Variation of the Geomagnetic Field Caused by Ionospheric Dynamo Currents

Magnetohydrodynamic modeling of three Van Allen Probes storms in 2012 and 2013

Ionospheric Day-to-Day Variability Around the Whole Heliosphere Interval in 2008

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