Global Simulation of Interaction of the Solar Wind with the Earth's Magnetosphere and Ionosphere Tatsuki Ogino Solar-Terrestrial Environment Laboratory Nagoya University The Korea-Japan Space Weather Modeling Workshop, 2008, Aug. 12

Space Weather Studies The Role of Global MHD Simulation of Solar Wind- Magnetosphere Interaction in Space Weather Studies

Satellite anomalies related to Space Weather are on the rise due to the increased use of composite materials instead of metal, and smaller, faster chip designs. The three principle anomaly types are: surface charging, internal charging, and Single Event Effects (SEE). The Sun’s magnetic field is propagated far beyond our planetary system by the solar wind. The interaction between this interplanetary magnetic field (IMF) and Earth’s own magnetic field is a significant component of Space Weather. The Ionosphere is a layer of the Earth’s upper atmosphere that contains free electrons and ions produced by solar UV radiation. Disruptions of the ionosphere can significantly affect radar, and radio communication. The Sun powers both the space weather and the terrestrial weather machines. Solar events, i.e., explosions of charged particles and the dynamics of magnetic and electric fields, cause huge changes in the near-Earth space environment. Satellites and communication signals must traverse this electric space. Solar-Terrestrial Environment Flares Solar Wind Magnetosphere Y. Kamide Interplanetary Magnetic Field X-rays Ionosphere Coronal Mass Ejections Polar Geosynchronous

1. Monitoring of space weather environment ・ Remote sensing of the sun ・ Real-time monitoring of the solar wind and magnetosphere- ionosphere-atmosphere 2. Construction of space weather prediction model ・ Construction of a highly reliable physical model in each region （ Sun, solar wind, magnetosphere, ionosphere, atmosphere ） ・ Establishment of an operational numerical prediction model ・ Unification of different numerical models Two Important Issues in Space Weather Study

Geospace Study Geospace Sun-earth system CME coronal hale Solar wind-magnetosphere- Ionosphere-thermosphere coupling High energy particles of radiation belts Solar wind-magnetosphere interaction Aurora solar wind Space Weather Map Courtesy of NASA electron ion Ring current inner belt Regional Coupling and Cross-Scale Coupling

1. Solar physics ・ Flare, CMEs ・ Plasma (density, velocity, temperature), photospheric magnetic field ・ Electromagnetic radiation (X ray), high energy particles 2. Space between sun and earth ・ CMEs, shock wave, formation and propagation of interplanetary disturbances ・ Propagation of solar wind and IMF 3. Solar wind and magnetosphere-ionosphere interaction 4. Substorms, magnetic storms, aurora 5. Variation of high energy particles (particles in the radiation belts) Influence of Solar Activity to Geospace Environment

Solar ActivityAtmosphereMagnetosphere Solar WindIonosphere Numerous Space Weather Models are Now Available Background Solar Wind SolarProtons Ring Current/Radiation Belts Geomagnetic Indices Coupled Thermosphere -Ionosphere Global Magnetospheric Simulations Electrojet Currents CME Propagation after Onsager of NOAA/SEC

What are requested to the Sun in Space Weather Study (1) ? Slow phenomena over 1 hour interval 1. Sun-solar wind-geospace interaction ・ Modeling of propagation of the solar wind from solar observations Input : Photospheric plasma (density, velocity, temperature) and photospheric magnetic field Output : Distribution of the plasma and magnetic field in heliosphere ・ Solar wind and earth’s magnetosphere-ionosphere interaction Simulation of magnetic storms and prediction (Dst) Increase and decrease of the radiation belt particles 2. Unification of sun-solar wind-earth’s magnetosphere interaction models 3. Integration between global model and micro model ・ Variations of the plasma sheet plasma and radiation belt particles

Prediction of Solar Wind Speed and IMF Polarity Nick Arge and Vic Pizzo, NOAA/SEC Input: Solar Photospheric Magnetic Field Lead Time:3 – 4 days Cadence: Daily Availability:Internal Web Sun Earth ACE

Sun Earth WIND/ACE Prediction of Relativistic Electrons Using Solar Wind Speed Linear Prediction Filter Technique of Baker et al., 1987

Input Kp Predicted Magnetospheric Electron Flux - 50 keV

What are reguested to the sun in Space Weather Study (2) ? Fast phenomena for about a minute A reason of separation between solar physics and geospace study in space weather ・ Requirement to know the solar wind (density, velocity, temperature) and 3 components of IMF about every 1 minute in order to predict geospace environment More accurate prediction of substorms and the maximum value of inductive electric field ・ How shorter time interval for variations of the solar wind and IMF can be given from the solar observations and modeling of sun and solar wind ? ・ Is it possible to construct a unifield model of a sun-solar wind-geospace interaction for time interval of a minute ? Solar wind and earth’s magnetosphere-ionosphere interaction model currently uses satellite observations as input ・ Solar wind (density, velocity, temperature) and 3 components of IMFs every a minute observed by AEC and WIND satellites are used as input of simulation

Sun Solar Wind IMF MagnetosphereIonosphere Atmosphere Thermosphere Solar Physics Solar wind-magnetosphere interaction M-I Coupling Thermosphere Model GSFC/NASA NRL, UCLA, Michigan Nagoya, NICT, Kyusyu (KRM, AMIE) (NCAR et al) Solar wind-magnetosphere-ionosphere-thermosphere interaction Physical Simulation Model of Regional Coupling Flare to CME CME to Earth

Space Weather Study magnetosphere Courtesy of ISAS sun Courtesy of NASA aurora S ｔ udy relationships between the solar activities and the geospace environment

Relative Location of ISTP Constellation during Sun-Earth Connection Event SOHOWIND Geotail Interball-Tail Polar 10 Re 100 Re 220Re EarthSun ACE

MHD Equations Density Momentum Plasma pressure Induction Current Following MHD Equations are solved as an initial-boundary Problem by Modified Leap-Frog method.

Simulation Model 3-dimensional Global magnetohydrodynamic (MHD) simulation of solar wind-magnetosphere/ionosphere interaction 1. Input Upstream parameters observed by satellites 2. Output Prediction of magnetoshere/ionosphere satellites like GEOTAIL, POLAR, Interball Ground-based observations shape, response, distribution of energy ・ ACE, WIND, IMP ・ solar wind and IMF data every 1 minute ・ comparison with observations ・

UT Bz By P Vx 

Polar cap electric potential open-closed boundary

Time evolution of polar cap potential 10 minute sampling 1 minute sampling

 Bz By Dp Vx WIND Data

AL, AU Index and Dst Index After WDC for Kyoto Time (hours) Times of Minimum value 04:31/22 AL AU 01:19 03:40 Time of Zero value 22/21 Times of Minimum value 06/ Magnetic storm event for October 21-23, 1999

23:48 01:19 03:16 04:31 07 every 10 minute sampling

Polar Cap Potential of Every 1 Minute Sampling

Examples of 3D global MHD simulation southward IMF

northward IMF

3D visualization by VRML (Virtual Reality Modeling Language) dipole tilt and southward IMF

dipole tilt and northward IMF

Goal of Space Weather Study 1. Construction of unifield physical model from the sun to earth 2. Prediction of indices for magnetospheric disturbances (Dst, AU, AL) and particle distribution in the radiation belts 3. Study of nonlinear phenomena (kinetics) of plasma by unifying the global model and micro (particle) model 4. Proposal of space weather map ・ Diagram of electric potential (or convection) in the polar region ・ Map of plasma distribution (high energy particles) in space from sun to earth