3-Dimensional Global MHD Simulation of Earth's Magnetosphere on the Event on November 17, 1996.


2000.1.22 by Tatsuki Ogino

Event on November 17, 1996 has been studied by using a 3-dimensional global magnetohydrodynamic (MHD) simulation of interaction between the solar wind and the earth's magnetosphere when the WIND data in the upstream was used as input of simulation. We have presented response of the earth's magnetosphere and ionosphere depending on practical variations of the solar wind and IMF (Interplanetary magnetic field) for the selected event and compare simulation results with SuperDARN observations.

In the simulation model the MHD equation and Maxwell's equation were solved as an initial and boundary problem due to modified leap-frog method. Number of grid points is (nx,ny,nz)=(500,100,200) and grid spacing is uniform and 0.5Re in three direction. Therefore the simulation domain is -220.25Re<x<30.25Re, -0.25Re<y<50.25Re, and -50.25Re<z<50.25Re.

The WIND satellite observations of the solar wind and magnetic field almost every 1 minute in GSM coordinates were used as input of this global MHD simulation. The practical input data is the solar wind number density, x-component of velocity, plasma pressure and IMF (Interplanetary magnetic field) y and z components in the GSM coordinates. In the simulation, we used the WIND data at the observed time and position as the input data at the upstream boundary at x=30Re and same time. Moreover, the electric conductivity in the ionosphere is Pedersen only and uniform by a value of 7S. Thus people need to consider these differences in compare the MHD simulation results with observations.

In summary, we could successfully carried out a global 3D MHD simulation of the solar wind-magnetosphere-ionosphere interaction when the WIND observations were used as input. Response of electric potential in the polar cap is very quick (less than 10 minutes) and strongly depends on variations of the IMF z component and the solar wind dynamic pressure. The earth's magnetosphere-ionosphere is much influenced by southward IMF than northward IMF (about 5 times). Thus effects of southward IMF become remarkable.

Response of the magnetotail and plasma sheet needs longer time (40-60 minutes) and the associated phenomena such as ionospheric convection in the midnight polar region also need longer time. We can apply the global 3D MHD model to an operational model in space weather study.

We presented three kind graphics output of cross sectional profiles of energy in the noon-midnight and equatorial planes, polar plots and configuration of magnetic field lines every 10 minutes. They are shown by movie (QuickTime and GIF formats), GIF format files and PostScript files.
We also presented three dimensional visualization of the magnetosphere by using VRML (Virtual Reality Modeling Language) and the vrml files (*.wrl) can be watched by VRML viewer such as "cosmo player" in the personal computers and workstations.

--readme.txt
  figure   ---- hashi01.ps      WIND plot given by Hashimoto
                hashi01.gif
                hashi02.ps      WIND plot given by Hashimoto
                hashi02.gif
                wi991117a.ps    WIND plot for 00:00-24:00
                wi991117a.gif
                wi991117b.ps    WIND plot for 17:30-20:30
                wi991117b.gif
                potent01.ps     simulated potential for 00:00-24:00
                potent01.gif
                potent02.ps     simulated potential for 17:30-20:30
                potent02.gif
                potent03.ps     simulated potential for 17:30-20:30 (scale)
                potent03.gif
                potent04.ps     simulated potential for 17:30-20:30 (1 min)
                potent04.gif
  movie    ---- zcc10511.gif    GIF movie, polar plots (17:30-20:30 1 minute)
                zcc10511.mov    can look by "xanim", polar plots (1 minute)
                zeb10511.gif    GIF movie, polar plots (17:30-20:30 1 minute)
                zeb10511.mov    can look by "xanim", polar plots (1 minute)
  movie2   ---- ze021390.gif    GIF movie, polar plots
                ze021390.mov    can look by "xanim", polar plots
                ze001067.gif    GIF movie, polar plots
                ze001067.mov    "xanim", polar plots
                ze073139.gif
                ze073139.mov
                zm001067.gif    GIF movie, magnetic field lines
                zm001067.mov    "xanim",  magnetic field lines
                zm021390.gif    GIF movie, magnetic field lines
                zm021390.mov    "xanim", magnetic field lines
                zm073139.gif
                zm073139.mov
                zz001067.gif    GIF movie, cross sectional profiles
                zz001067.mov    "xanim", cross sectional profiles
                zz021390.gif
                zz021390.mov
                zz073139.gif
                zz073139.mov
                zd001067.gif    GIF movie, cross sectional pattern
                zd001067.mov    "xanim", cross sectional pattern
                zd021390.gif
                zd021390.mov
                zd073139.gif
                zd073139.mov

  psz25e2b ----                polar convection and potential
                eb1051.ps.gz   PostScript file  17:31 - 17:40
                     |
                eb1221.ps.gz   PostScript file  20:21 - 20:30

                eb10511.gif    gif file   t=17:31
                     |
                eb122110.gif   gif file   t=20:30

  psz25e2c ---                 vorticity and parallel velocity
                ec1051.ps.gz   PostScript file  17:31 - 17:40
                     |
                ec1221.ps.gz   PostScript file  20:21 - 20:30

                ec10511.gif    gif file   t=17:31
                     |
                ec122110.gif   gif file   t=20:30

vrml -------- Three dimensional visualization of the magnetosphere 
              by using VRML (Virtual Reality Modeling Language)
              vrml files (*.wrl) can be watched by cosmo player.
         1835d.wrl      magnetospheric structure at 18:35
         1920d.wrl      magnetospheric structure at 19:20
         1934d.wrl
         1950d.wrl
         2000d.wrl
         2010d.wrl
         1838.B.ondo.wrl   many field lines are drawn at 18:38
         1842.B.ondo.wrl   many field lines are drawn at 18:42
         1901.B.ondo.wrl
         1936.B.ondo.wrl
         1939.B.ondo.wrl

vrml -------- Three dimensional visualization with transparent technique
         1835d2.wrl      magnetospheric structure at 18:35
         1920d2.wrl      magnetospheric structure at 19:20
         1934d2.wrl
         1950d2.wrl
         2000d2.wrl
         2010d2.wrl
         1838.C.ondo.wrl   many field lines are drawn at 18:38
         1842.C.ondo.wrl   many field lines are drawn at 18:42
         1901.C.ondo.wrl
         1936.C.ondo.wrl
         1939.C.ondo.wrl



Correspondence of time and file name is as follows, Event on November 17, 1999 for 17:31 - 20:30

file name       hh:mm
ec1051.ps.gz    17:31 -17:40  PostScript file
ec10511.gif     17:31
ec10512.gif     17:32
ec10513.gif     17:33
ec10514.gif     17:34
ec10515.gif     17:35
ec10516.gif     17:36
ec10517.gif     17:37
ec10518.gif     17:38
ec10519.gif     17:39
ec105110.gif    17:40
ec1061.ps.gz    17:41 -17:50  PostScript file
ec10611.gif     17:41

ec1221.ps.gz    20:21 -20:30  PostScript file
ec12211.gif     20:21
ec12212.gif     20:22
ec12213.gif     20:23
ec12214.gif     20:24
ec12215.gif     20:25
ec12216.gif     20:26
ec12217.gif     20:27
ec12218.gif     20:28
ec12219.gif     20:29
ec122110.gif    22:30

file name      time interval
zz001067.gif   00:10-12:00   every 10 minutes  gif movie
zz001067.mov   00:10-12:00   every 10 minutes  "xanim" movie
zz021390.gif   00:10-24:00   every 10 minutes  gif movie
zz021390.mov   00:10-24:00   every 10 minutes  "xanim" movie
zz073139.gif   12:10-24:00   every 10 minutes  gif movie
zz073139.mov   12:10-24:00   every 10 minutes  "xanim" movie

Acknowledgments, The computer simulation was performed on Fujitsu VPP5000-16PE in the Computer Center of Nagoya University. The WIND data of the solar wind and magnetic field in ISTP Key Parameters was used courtesy of Drs. R.P. Lepping and K.W. Ogilvie.

CONTACTS:
Tatsuki Ogino
Solar-Terrestrial Environment Laboratory
Nagoya University
3-13 Honohara, Toyokawa, Aichi 442-8507, Japan
E-mail: ogino[AT]stelab.nagoya-u.ac.jp
TEL: +81-533-89-5207 FAX: +81-533-89-5090