Global MHD Simulation with BATSRUS from CCMC

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Global MHD Simulation with BATSRUS from CCMC

• ESS 265
• UCLA1
• (Yasong Ge, Megan Cartwright, Jared Leisner, and
  Xianzhe Jia)

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Outline

• Description of Model
• Global Magnetophere
• Dayside Magnetopause and Solar Wind
• Cusp Region Investigation
• Magnetotail Investigation

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BATS-R-US Model

• BATS-R-US, the Block-Adaptive-Tree-Solarwind-Roe-U
  pwind-Scheme, was developed by the Computational
  Magnetohydrodynamics (MHD) Group at the
  University of Michigan, now Center for Space
  Environment Modeling (CSEM). It was designed
  using the Message Passing Interface (MPI) and the
  Fortran90 standard and executes on a massively
  parallel computer system.
• The BATS-R-US code solves 3D MHD equations in
  finite volume form using numerical methods
  related to Roe's Approximate Riemann Solver.
  BATSRUS uses an adaptive grid composed of
  rectangular blocks arranged in varying degrees of
  spatial refinement levels. The magnetospheric MHD
  part is attached to an ionospheric potential
  solver that provides electric potentials and
  conductances in the ionosphere from
  magnetospheric field-aligned currents.

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Input parameters and boundary conditions

• Fixed Solar Wind velocity of 400km/s, solar wind
  density of 5X106 protons/m3 and temperature of
  1X105.
• Two hours initialization with steady southward
  IMF.
• Turning IMF northward for the last two hours.
• Default ionosphere without corotation.

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Magnetic field lines t0000
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Magnetic field lines t0100
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Magnetic field lines t0158
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Magnetic field lines t0200
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Magnetic field lines t0204
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Magnetic field lines t0206
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Magnetic field lines t0208
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Magnetic field lines t0216
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Magnetic field lines t0230
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Magnetic field lines t0246
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Magnetic field lines t0300
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Magnetic field lines t0316
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Magnetic field lines t0320
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Magnetic field lines t0330
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Magnetic field lines t0346
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Magnetic field lines t0400
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Pressure Velocity vectors
t 0000
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0100
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0158
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0200
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0204
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0206
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0208
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0216
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0230
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0246
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0300
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0316
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0320
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0330
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0346
Noon-Midnight meridian view
Equatorial view
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Pressure Velocity vectors
t 0400
Noon-Midnight meridian view
Equatorial view
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Plasma temperature
t 0000
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Plasma temperature
t 0100
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Plasma temperature
t 0158
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Plasma temperature
t 0200
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Plasma temperature
t 0204
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Plasma temperature
t 0206
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Plasma temperature
t 0208
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Plasma temperature
t 0216
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Plasma temperature
t 0230
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Plasma temperature
t 0246
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Plasma temperature
t 0300
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Plasma temperature
t 0316
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Plasma temperature
t 0320
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Plasma temperature
t 0330
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Plasma temperature
t 0346
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Plasma temperature t 0400
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Jy t 0000
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Jy t 0100
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Jy t 0158
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Jy t 0200
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Jy t 0216
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Jy t 0230
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Jy t 0246
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Jy t 0300
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Jy t 0316
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Jy t 0320
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Jy t 0330
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Jy t 0346
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Jy t 0400
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Ionospheric potential velocity vectors
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Ionospheric potential velocity vectors
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Ionospheric potential velocity vectors
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Ionospheric potential velocity vectors
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Ionospheric potential velocity vectors
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Ionospheric potential velocity vectors
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Ionospheric potential velocity vectors
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Ionospheric potential velocity vectors
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Summary for Global View

• 3D B field lines show tail flaring on southward
  IMF and flux return (tail field relaxation) on
  northward IMF. NENL retreats a while after IMF
  turning.
• Plasma pressure in magnetosheath increases
  temporarily just after northward IMF hits
  magnetophere.
• Magnetosheath flows rotate to field-aligned.
• Two convection cells in tail shows the ground
  state of magnetophere.
• Thin plasma sheet is present on southward IMF and
  has a large y range. Plasma sheet density and
  size in y direction decrease, but plasma
  expansion in z direction follows the NENL
  retreating.
• Thin current sheet also is shown at Jy plot.
• Southward IMF gives strong magnetopause current,
  and the current fades off after IMF turning.
• DP-2 current system is shown when IMF is
  southward and dies off when IMF is turned
  northward.

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Pressure(color) and velocity(vector) and B
field lines at t000
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t100
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t158
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t200
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t204
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t206
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t208
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t216
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t230
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t246
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t316
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t300
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t330
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t346
Left is noon-midnight meridian Right is
equatorial plane
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Pressure(color) and velocity(vector) and B
field lines at t400
Left is noon-midnight meridian Right is
equatorial plane
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Summary for Magnetopause

• At the dayside magnetosheath, the plasma pressure
  increases due to the turning of IMF from
  southward to northward and the turning off of
  dayside reconnection.
• Plasma pressure in dayside magnetosheath finally
  falls off.
• Pressure stabilizes at subsolar point between t
  246 and 300
• Magnetic field flux piles up at dayside
  magnetopause due to the turning of IMF.

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Pressure(color) and velocity(vector) and B
field lines at t000
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Pressure(color) and velocity(vector) and B
field lines at t100
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Pressure(color) and velocity(vector) and B
field lines at t158
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Pressure(color) and velocity(vector) and B
field lines at t200
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Pressure(color) and velocity(vector) and B
field lines at t204
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Pressure(color) and velocity(vector) and B
field lines at t206
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Pressure(color) and velocity(vector) and B
field lines at t208
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Pressure(color) and velocity(vector) and B
field lines at t212
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Pressure(color) and velocity(vector) and B
field lines at t216
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Pressure(color) and velocity(vector) and B
field lines at t230
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Pressure(color) and velocity(vector) and B
field lines at t246
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Pressure(color) and velocity(vector) and B
field lines at t300
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Pressure(color) and velocity(vector) and B
field lines at t330
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Pressure(color) and velocity(vector) and B
field lines at t346
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Pressure(color) and velocity(vector) and B
field lines at t400
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LogT(color) and JXB(vector) and B field lines at
t000
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LogT(color) and JXB(vector) and B field lines at
t100
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LogT(color) and JXB(vector) and B field lines at
t158
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LogT(color) and JXB(vector) and B field lines at
t200
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LogT(color) and JXB(vector) and B field lines at
t204
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LogT(color) and JXB(vector) and B field lines at
t206
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LogT(color) and JXB(vector) and B field lines at
t208
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LogT(color) and JXB(vector) and B field lines at
t212
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LogT(color) and JXB(vector) and B field lines at
t216
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LogT(color) and JXB(vector) and B field lines at
t230
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LogT(color) and JXB(vector) and B field lines at
t246
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LogT(color) and JXB(vector) and B field lines at
t300
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LogT(color) and JXB(vector) and B field lines at
t316
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LogT(color) and JXB(vector) and B field lines at
t330
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LogT(color) and JXB(vector) and B field lines at
t346
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LogT(color) and JXB(vector) and B field lines at
t400
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Summary for Cusp Region

• In the cusp, the pressure decreases significantly
  as the IMF turns northward.
• At cusp region, flow is parallel the magnetopause
  when IMF is southward, then rotates
  counter-clockwise until it points perpendicular
  to the magnetopause. This is the inflow of solar
  wind particles due to reconnection.
• The cusp region immigrates northward in northward
  IMF.
• Magnetopause moves out, polar cap shrinks (green
  lines).
• Hot particle concentration moves up from the ram
  side to the upper flank, settling in the region
  of reconnection. Polar cap disappears?
• JxB force goes from about equal between polar and
  closed field lines to much larger on northern
  side of reconnection region (not exactly sure
  what to make of this...current in reconnection
  region is predominantly field-aligned?).

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B field lines in tail at t000
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B field lines in tail at t100
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B field lines in tail at t158
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B field lines in tail at t200
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B field lines in tail at t204
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B field lines in tail at t206
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B field lines in tail at t208
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B field lines in tail at t210
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B field lines in tail at t216
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B field lines in tail at t230
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B field lines in tail at t246
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B field lines in tail at t300
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B field lines in tail at t316
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B field lines in tail at t320
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B field lines in tail at t322
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B field lines in tail at t324
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B field lines in tail at t326
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B field lines in tail at t328
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B field lines in tail at t330
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B field lines in tail at t346
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B field lines in tail at t400
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Number Density and Velocity in tail at t000
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Number Density and Velocity in tail at t100
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Number Density and Velocity in tail at t158
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Number Density and Velocity in tail at t200
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Number Density and Velocity in tail at t204
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Number Density and Velocity in tail at t206
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Number Density and Velocity in tail at t208
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Number Density and Velocity in tail at t216
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Number Density and Velocity in tail at t230
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Number Density and Velocity in tail at t246
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Number Density and Velocity in tail at t300
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Number Density and Velocity in tail at t316
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Number Density and Velocity in tail at t330
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Number Density and Velocity in tail at t346
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Number Density and Velocity in tail at t400
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Summary from Tail View

• Dayside reconnection in southward IMF transports
  magnetic flux into tail. Tail is flaring due to
  flux pile-up.
• Near-Earth reconnection sustains when IMF is
  southward.
• Northward IMF decreases dayside reconnection rate
  and tail reconnection return flux back to
  dayside. NENL retreats from 20 RE to distant
  tail after 316.
• Plasma sheet tenuates and extends tailward with
  the retreating of neutral line.

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Summary

• Dayside reconnection due to southward IMF erodes
  dayside magnetosphere and magnetic flux piles up
  at tail.
• Northward IMF ceases (almost) dayside
  reconnection and erosion of dayside
  magnetosphere.
• Tail reconnection returns flux back to dayside,
  and magnetosphere relaxes to the ground state.