The GUMICS-4 global MHD magnetosphere–ionosphere coupling simulation

Janhunen, P.; Palmroth, Minna; Laitinen, T. V.; Honkonen, Ilja; Juusola, Liisa; Facskó, G.; Pulkkinen, Tuija

doi:10.1016/j.jastp.2012.03.006

Cited by 105 publications

(124 citation statements)

References 41 publications

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“…The requirements for the magnetospheric plasma simulation are well within the boundaries set by GUMICS-4 of ±64 R E in y and z and up to 32 R E in x. The main limitations of the model, as described in Janhunen et al [2012], are magnetotail reconnection and near-Earth plasma modeling (<3.7 R E ). The first limitation is not relevant, as we only generate X-ray emission data at x > 0, and the second limitation is taken care of by use of a magnetopause position mask.…”

Section: A Reexamination Of the Methodsmentioning

confidence: 86%

“…We use an MHD model for this comparative study and a more recent magnetopause model. To determine the properties of the solar wind plasma throughout the magnetosheath, we use the GUMICS-4 (Global Unified Magnetosphere-Ionosphere Coupling Simulation) MHD code 10.1002/2015JA022292 [Janhunen et al, 2012]. The process to acquire and convert the MHD grid into an X-ray emissivity datacube is described in section 2.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modeling the magnetospheric X‐ray emission from solar wind charge exchange with verification from XMM‐Newton observations

et al. 2016

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An MHD‐based model of terrestrial solar wind charge exchange (SWCX) is created and compared to 19 case study observations in the 0.5–0.7 keV emission band taken from the European Photon Imaging Cameras on board XMM‐Newton. This model incorporates the Global Unified Magnetosphere‐Ionosphere Coupling Simulation‐4 MHD code and produces an X‐ray emission datacube from O7+ and O8+ emission lines around the Earth using in situ solar wind parameters as the model input. This study details the modeling process and shows that fixing the oxygen abundances to a constant value reduces the variance when comparing to the observations, at the cost of a small accuracy decrease in some cases. Using the ACE oxygen data returns a wide ranging accuracy, providing excellent correlation in a few cases and poor/anticorrelation in others. The sources of error for any user wishing to simulate terrestrial SWCX using an MHD model are described here and include mask position, hydrogen to oxygen ratio in the solar wind, and charge state abundances. A dawn‐dusk asymmetry is also found, similar to the results of empirical modeling. Using constant oxygen parameters, magnitudes approximately double that of the observed count rates are returned. A high accuracy is determined between the model and observations when comparing the count rate difference between enhanced SWCX and quiescent periods.

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Section: A Reexamination Of the Methodsmentioning

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Modeling the magnetospheric X‐ray emission from solar wind charge exchange with verification from XMM‐Newton observations

et al. 2016

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“…Instead, global magnetohydrodynamic (MHD) models are often used to provide a large-scale view of the dynamical evolution in real-time. The best known models include the Lyon-Fedder-Mobarry (LFM) (Lyon et al, 2004), BATS-R-US (Powell et al, 1999), Open General Geospace Circulation Model (OpenGGCM) (Raeder et al, 2009), Ogino Model (Ogino et al, 1994 and the Grand Unified Magnetosphere-Ionosphere Coupling Simulation (GUMICS) (Janhunen et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

The impact on global magnetohydrodynamic simulations from varying initialisation methods: results from GUMICS-4

et al. 2017

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Abstract. We investigate the effects of different initialisation methods of the GUMICS-4 global magnetohydrodynamic (MHD) simulation to the dynamics in different parts of the Earth's magnetosphere and hence compare five 12 h simulation runs that were initiated by 3 h of synthetic data and followed by 9 h of solar wind measurements using the OMNI data as input. As a reference, we use a simulation run that includes nearly 60 h of OMNI data as input prior to the 9 h interval examined with different initialisations. The selected interval is a high-speed stream event during a 10-day interval (12-22 June 2007). The synthetic initialisations include stepwise, linear and sinusoidal functions of the interplanetary magnetic field with constant density and velocity values. The results show that the solutions converge within 1 h to give a good agreement in both the bow shock and the magnetopause position. However, the different initialisation methods lead to local differences which should be taken into consideration when comparing model results to satellite measurements.

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“…The GUMICS54 used two simulation domains: The ionospheric domain, which is a tilted dipole field region within 3.7 RE, and the magnetospheric domain outside the ionospheric domain. These domains were coupled to each other, which was updated every four seconds in the simulation (see more in Janhunen et al, 2012, and references therein).…”

Section: Figure_6mentioning

confidence: 99%

Properties of plasma near the moon in the magnetotail

Kallio

Facskó

2015

Planetary and Space Science

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Plasma physical processes near the lunar surface depend on the properties of the ambient plasma. However, the Moon spends almost half of its time downstream of the Earth's bow shock where the plasma near the Moon is anticipated to differ from the undisturbed solar wind. We have made statistical analysis of plasma parameters and the magnetic field near the orbit of Moon by using a global magnetohydrodynamic simulation made for a time period which covers a full year. The study shows that the velocity and the magnetic field downstream of the bow shock near the lunar orbit are much alike in the solar wind. This suggests that these plasma parameters near the Moon is controlled and driven by the solar wind. Density and temperature of the plasma are, however, strongly modified by the Earth. Consequently, the characteristic length scale of the plasma layer above the lunar surface, the Debye length, is controlled by plasma physical processes in the Earth's magnetosphere. The derived plasma and field parameters make it possible to analyse in detail the direct plasma-surface interaction at the Moon when it is in the magnetotail. of Sciences, Sopron, Hungary (facsko.gabor@csfk.mta.hu) Plasma physical processes near the lunar surface depend on the properties of the ambient plasma. However, the Moon spends almost half of its time downstream of the Earth's bow shock where the plasma near the Moon is anticipated to differ from the undisturbed solar wind. We have made statistical analysis of plasma parameters and the magnetic field near the orbit of Moon by using a global magnetohydrodynamic simulation made for a time period which covers a full year. The study shows that the velocity and the magnetic field downstream of the bow shock near the lunar orbit are much alike in the solar wind. This suggests that these plasma parameters near the Moon is controlled and driven by the solar wind. Density and temperature of the plasma are, however, strongly modified by the Earth. Consequently, the characteristic length scale of the plasma layer above the lunar surface, the Debye length, is controlled by plasma physical processes in the Earth's magnetosphere. The derived plasma and field parameters make it possible to analyse in detail the direct plasma5surface interaction at the Moon when it is in the magnetotail. Plasma physical processes near the Moon depend on the properties of the ambient plasma. The Moon does not have an atmosphere or a global intrinsic magnetic field and, therefore, the plasma can interact directly with the surface. This interaction results in physical processes at wide length scales of order of meters to the size of the Moon. The direct plasma5surface interaction results in small scale physical processes near the lunar surface within a sheath region, the Debye layer, where an electric field is formed due to the charge separation between solar wind protons and electrons from the solar wind and photoelectron from the lunar surface. The size of the Debye layer and the electric field within it depend on the pr...

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The GUMICS-4 global MHD magnetosphere–ionosphere coupling simulation

Cited by 105 publications

References 41 publications

Modeling the magnetospheric X‐ray emission from solar wind charge exchange with verification from XMM‐Newton observations

Modeling the magnetospheric X‐ray emission from solar wind charge exchange with verification from XMM‐Newton observations

The impact on global magnetohydrodynamic simulations from varying initialisation methods: results from GUMICS-4

Properties of plasma near the moon in the magnetotail

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