Global Simulation of Interaction of the Solar Wind with

the Earth's Magnetosphere and Ionosphere 　

Tatsuki Ogino

Solar-Terrestrial Environment LaboratoryNagoya 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).

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 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 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.

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

FlaresFlares

Solar Solar WindWind

MagnetosphereMagnetosphere

Y. Kamide

Interplanetary Magnetic Field

X-X-raysrays

IonospherIonospheree

Coronal Mass Coronal Mass EjectionsEjections

PolarGeosynchronousGeosynchronous

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

GeospaceSun-earth system

CMEcoronal hale Solar wind-magnetosphere-

Ionosphere-thermosphere coupling

High energy particles of radiation beltsSolar wind-magnetosphereinteraction

Aurora

solar wind

Space Weather Map

Courtesy of NASA

electron

ionRing 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 Activity AtmosphereMagnetosphereSolar Wind Ionosphere

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 PolarityNick Arge and Vic Pizzo, NOAA/SEC

Input: Solar Photospheric Magnetic Field

Lead Time: 3 – 4 daysCadence: DailyAvailability: 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

SunSolar Wind

IMFMagnetosphere Ionosphere

AtmosphereThermosphere

Solar Physics

Solar wind-magnetosphere interaction

M-I Coupling

Thermosphere Model

GSFC/NASANRL, UCLA, MichiganNagoya, 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 betweenthe solar activities and the geospace environment

Relative Location of ISTP Constellation during Sun-Earth Connection Event

SOHO WIND

Geotail

Interball-Tail

Polar

10 Re

100 Re

220Re

EarthSun

ACE

MHD Equations

2)(

Dt

V

Φ

BJVVV

gPt

11)(

PDPPt

PP

2)(

VV

BBVB 2)( t

dBBJ

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・

00 06 12 18 24 UT

Bz

By

P

Vx

Polar cap electric potential

open-closed boundary

Time evolution of polar cap potential10 minute sampling 1 minute sampling

Bz

By

Dp

Vx

WIND Data

00:00-24:00, 21-22/ 10, 1999

-2500

-2000

-1500

-1000

-500

0

500

Time(minutes)

AUAL

AL, AU Index and Dst Index

00:00 - 24:00, 21-23/ 10, 1999 Dst

-250

-200

-150

-100

-50

0

50

(nT)

Dst

After WDC for Kyoto

Time (hours)

Times of

Minimum value 04:31/22

ALAU

01:19

03:40

Time of Zero value22/21

Times of

Minimum value 06/22

00 12 　 00 12 24 1 　 25 　 49 　 72

Magnetic storm event for October 21-23, 1999

23:4801:19

03:1604:31

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