Ionospheric Power Consumption in Global MHD Simulation Predicted From Solar Wind Measurements

2004 ◽  
Vol 32 (4) ◽  
pp. 1511-1518 ◽  
Author(s):  
M. Palmroth ◽  
H.E.J. Koskinen ◽  
T.I. Pulkkinen ◽  
P. Janhunen
Keyword(s):  
Solar Wind ◽  
Power Consumption ◽  
Mhd Simulation ◽  
Wind Measurements ◽  
Global Mhd Simulation

scholarly journals Real-time global MHD simulation of the solar wind interaction with the earth’s magnetosphere

2008 ◽  
Vol 42 (9) ◽  
pp. 1504-1509 ◽  
Author(s):  
H. Shimazu ◽  
K. Kitamura ◽  
T. Tanaka ◽  
S. Fujita ◽  
M.S. Nakamura ◽  
...  
Keyword(s):  
Solar Wind ◽  
Real Time ◽  
Solar Wind Interaction ◽  
Mhd Simulation ◽  
Earth’S Magnetosphere ◽  
Earth's Magnetosphere ◽  
Global Mhd Simulation

scholarly journals Ionospheric energy input as a function of solar wind parameters: global MHD simulation results

2004 ◽  
Vol 22 (2) ◽  
pp. 549-566 ◽  
Author(s):  
M. Palmroth ◽  
P. Janhunen ◽  
T. I. Pulkkinen ◽  
H. E. J. Koskinen
Keyword(s):  
Solar Wind ◽  
Joule Heating ◽  
Temporal Variations ◽  
Simulation Code ◽  
Mhd Simulation ◽  
Modeling And Forecasting ◽  
Storms And Substorms ◽  
Simulation Results ◽  
Global Mhd Simulation ◽  
Solar Wind Parameters

Abstract. We examine the global energetics of the solar wind magnetosphere-ionosphere system by using the global MHD simulation code GUMICS-4. We show simulation results for a major magnetospheric storm (6 April 2000) and a moderate substorm (15 August 2001). The ionospheric dissipation is investigated by determining the Joule heating and precipitation powers in the simulation during the two events. The ionospheric dissipation is concentrated largely on the dayside cusp region during the main phase of the storm period, whereas the nightside oval dominates the ionospheric dissipation during the substorm event. The temporal variations of the precipitation power during the two events are shown to correlate well with the commonly used AE-based proxy of the precipitation power. The temporal variation of the Joule heating power during the substorm event is well-correlated with a commonly used AE-based empirical proxy, whereas during the storm period the simulated Joule heating is different from the empirical proxy. Finally, we derive a power law formula, which gives the total ionospheric dissipation from the solar wind density, velocity and magnetic field z-component and which agrees with the simulation result with more than 80% correlation. Key words. Ionosphere (modeling and forecasting) – Magnetospheric physics (magnetosphere-ionosphere interactions; storms and substorms)

scholarly journals A general Cluster data and global MHD simulation comparison

2008 ◽  
Vol 26 (11) ◽  
pp. 3411-3428 ◽  
Author(s):  
P. Daum ◽  
M. H. Denton ◽  
J. A. Wild ◽  
M. G. G. T. Taylor ◽  
J. Šafránková ◽  
...  
Keyword(s):  
Large Scale ◽  
Numerical Models ◽  
Mhd Simulation ◽  
Global Context ◽  
Cluster Data ◽  
Verification Methods ◽  
Modelling Studies ◽  
Global Mhd Simulation ◽  
The Many

Abstract. Among the many challenges facing the space weather modelling community today, is the need for validation and verification methods of the numerical models available describing the complex nonlinear Sun-Earth system. Magnetohydrodynamic (MHD) models represent the latest numerical models of this environment and have the unique ability to span the enormous distances present in the magnetosphere, from several hundred kilometres to several thousand kilometres above the Earth's surface. This makes it especially difficult to develop verification and validation methods which posses the same range spans as the models. In this paper we present a first general large-scale comparison between four years (2001–2004) worth of in situ Cluster plasma observations and the corresponding simulated predictions from the coupled Block-Adaptive-Tree-Solarwind-Roe-Upwind-Scheme (BATS-R-US) MHD code. The comparison between the in situ measurements and the model predictions reveals that by systematically constraining the MHD model inflow boundary conditions a good correlation between the in situ observations and the modeled data can be found. These results have an implication for modelling studies addressing also smaller scale features of the magnetosphere. The global MHD simulation can therefore be used to place localised satellite and/or ground-based observations into a global context and fill the gaps left by measurements.

Magnetosheath high speed jets and foreshock transients observed by Cluster and MMS

2021 ◽  
Author(s):  
C.-Philippe Escoubet ◽  
Keyword(s):  
Solar Wind ◽  
High Speed ◽  
Cone Angle ◽  
Bow Shock ◽  
Magnetic Data ◽  
Energetic Ions ◽  
Dust Clouds ◽  
Simultaneous Measurements ◽  
Wind Measurements ◽  
Dominant Period

<p>Magnetosheath High Speed Jets (HSJs) are regularly observed downstream of the Earth’s bow shock. Determining their origin from spacecraft observations is however a challenge since (1) L1 solar wind monitors are usually used with their inherent inaccuracy when plasma and magnetic data are propagated to the bow shock, (2) the number of measurement points around the bow shock are always limited. Various mechanisms have been proposed to explain HSJs such as bow shock ripples, solar wind discontinuities, foreshock transients, pressure pulses or nano dust clouds and it is difficult to relate these to HSJs with the lack of simultaneous measurements near the bow shock and immediately upstream.  We will use a special Cluster campaign, where one spacecraft was lagged 8 hours behind the three other spacecraft, to obtain near-Earth solar wind measurements upstream of the bow shock, together with simultaneous measurements in the magnetosheath. The event of interest is first observed by ACE on 13 January 2019 as a short 10 minutes period of IMF-Bx dominant (cone angle around 140 deg.). This IMF-Bx dominant period is also observed, one hour later, by THEMIS B and C (ARTEMIS) and Geotail, which were at 60 and 25 R<sub>E</sub> from Earth on the dawnside. Cluster 1 and Cluster 2 just upstream of the bow shock, at 17 R<sub>E</sub> from Earth, observed also such IMF-Bx dominant period together with energetic ions reflected from the bow shock and foreshock transients. Preliminary analysis indicate that these transients would be hot flow anomalies. Finally, Cluster 3 and 4 and MMS1-4, a few R<sub>E</sub> from each other downstream of the shock, observed a turbulent magnetosheath with HSJs for 15 minutes. The HSJ characteristics are investigated with the constellation of 6 spacecraft, as well as their relation to hot flows anomalies observed upstream.</p>

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