The Magnetosphere and Plasmasphere

1
The Magnetosphere and Plasmasphere

• CSI 769
• 3rd section, Oct. Nov. 2005
• J. Guillory

2

• Lecture 7 (Oct.18)
• Bow shock scattering Magnetosphere structure,
  charged particle orbits
• Advance reading Gombosi Ch.1 6 (and/or Parks
  Ch. 4, 8 10), Tascione Ch.4, and Sci. Am. Apr.
  1991 Collisionless Shock Waves
• Lecture 8 (Oct. 25)
• Dawn-dusk electric field gyrokinetic codes
  magnetotail current sheet
• Advance reading Gombosi Ch. 7 14, Parks Sec.
  7.8 11.5), Tasc. Ch 5
• Lecture 9 (Nov. 1)
• MHD codes boundary conditions parallel
  E-fields precipitation satellite diagnostics
• Advance reading Gombosi Ch. 4 , Parks Sec. 7.7
• In conjunction with the last topic
• Joel Fedder (NRL) is scheduled for a Space
  Sciences Seminar on his MHD magnetosphere code,
  Wed. 10/26, 300 p.m., 206
• Please attend.

3
Bow shock
4
Perpendicular shock
5
Oblique shock
6
waves particles in upstream foreshock
From Sagdeev Kennel, Sci. Am. Apr. 1991
7
Foreshock region
8
Current in shock layer
From G. K. Parks, Physics of Space Plasmas, AW
1991
9
Components of v along B and the shock surface,
for incident reflected particles
10
Repeated reflections from solitons near nonsteady
shock
From Sagdeev Kennel, Sci. Am. Apr. 1991
11
ISEE In-situ B-field measurements across bow shock
12
Collisionless shock structureHybrid code
simulation by M. Leroy et al, GRL 8, 1269 (1981)
C. S. Wu, D. Winske et al., Sp.Sci. Revws 37, 63
(1984)
13
Ion distributions near shock
14
Phase space in normal direction
Electric potential structure
15
Incoming particle scattering

• Stochastic Injection of Energetic Particles from
  Bow Shock and from Tailward reconnection region
• Nonadiabatic because gyroradius B scale-length
  locally
• Particle orbit diffusion due to field
  fluctuations
• Some particles accelerated near bow shock and
  magnetic reconnection regions

16
Magnetic field geometry
17
Model field topology for northward IMF
IMF dipole
18
Model field topology for southward IMF
From G. K. Parks, Physics of Space Plasmas, AW
1991
19
Field line motion with southward IMF (after J.
Dungey, 1961). North is DOWN in this fig.
From G. K. Parks, Physics of Space Plasmas, AW
1991
20
Detail of day-side reconnection field flows
21
Field near reconnection region(more on
reconnection later)
22
Inner magnetosphereEnergetic proton density
contours, showing South Atlantic anomaly
23
Mag. dipole offset from rotation axisand tilted
24
Van Allen Belts

• Inner belt energetic protons
• from cosmic ray albedo neutron decay (CRAND)
  and from diffusion from elsewhere.
• Outer belt somewhat energetic ions
• from solar wind injection and
• accelerated from ionosphere,
• and diffusion from elsewhere.

25
Approx. avg. contours of spatial distribution of
trapped energetic protons electrons
(Van Allen, 1968)
26
NSSDC quiet-time static empirical model (AP-8)
of energetic proton flux density
J. D. Gaffey D. Belitza, J. Spacecraft
Rockets 31, 172 (1994)
27
NSSDC quiet-time static empirical model (AE-8)
of energetic electron flux density
J. D. Gaffey D. Belitza, J. Spacecraft
Rockets 31, 172 (1994)
28
Calculated energetic proton lifetimes (x ne) in
inner Van Allen belt under quiescent conditions
R. C. Wentworth, Pitch Angle Diffusion.. ,
Phys. Fluids 6, 431 (1963)
29
Satellite measurement of proton density vs L,
during quiet and CME-arrival conditions
OGO-5 measuremts
R. Chappell et al, JGR 75, 50 (1970)
30
Squeezing the magnetospherequasistatic pressure
balance estimate

• Ram pressure of CME arrival IMF
• rv2
• vs
• interior particlefield pressure
• Increasing B produces inductive E fields and
  currents

31
Energy transfer from CME to magnetosphere time
delay
From Tascione, after Baker et al, JGR 90, 1205
(1985)
32
Particle currents in the magnetosphere
33
Ring current reduces B at surface

• After CME compression of day-side magnetosphere,
  Bhoriz at RE decreases
• 1 hr after sudden-commencement rise, and
  stays reduced for 1-3 days, gradually returning
  to pre-storm values.
• This is correlated with injection of 10-100keV
  magnetotail particles into ring-current region.

34
Global magnetic change index (Tascione sec 4.7)

• K integer, 0 9 3-hr average of DB, on
  quasi-log scale, for each of several ground
  locations
• Kp average of Ks from 12 locations between 48
  63 degrees latitude, averaged with local
  seasonal variation filtered out

35
Dst index (Tascione p.51)

• Hourly avg. (from 4 low-latitude ground stations)
  of changes in horizontal component of B, with
  seasonal variations subtracted out.
• A measure of changes in ring-current intensity

36
AE (Auroral electrojet) index

• Spread between max positive max negative
  changes in horizontal component of B at several
  auroral-latitude locations, 62.5 71.6 degree
  latitudes
• Global AE maximum of the positive changes in
  horizontal component at any such location -
  maximum of the negative changes in horizontal
  component at any such location

37
Electric fields and more currents plasma flows

• Plasma corotation-induced E field
• E - (w x r) x B
• BoRE (RE/r)2 (2sin l el cos l er)
  approximately, for dipole B.
• Inner part of earths magnetosphere corotates.
• Added to dawn-dusk E field due to solar wind

38
Model E-fields in equatorial plane
39
Collisionless plasma flow (not currents) in E
perpendicular to B

• vD/c E x B /B2 (cgs) , if (as usual) E (cgs)
  ltlt B (G)

40
B-Field-aligned currents and fields

• High-conductivity acceleration-limited currents
  along B-lines
• Downstreaming charges arrive die at dense
  ionosphere, producing auroral glow.
• Upstreaming charges from ionosphere populate
  plasmasphere and magsphere.

41

From Tascione
42
Field-aligned ion beam distributions in plasma
sheet boundary layer from ISEE-1, 16 Feb
1980.(T.E. Eastman, R.J. DeCoster L.A. Frank,
in Cross-Scale Coupling in Space Plasmas
43
Velocities for steady-state polar wind with no
field-aligned current
S. B. Ganguli, H. B. Mitchell, P. Palmadesso,
NRL Memo Report 5673, 1985
44
Velocities (magnitude) 70 min after onset of a
current of -1 mA/m2 at 1500 km
S. B. Ganguli, H. B. Mitchell, P. Palmadesso,
NRL Memo Report 5673, 1985
45
Heating by these currents
S. B. Ganguli, H. B. Mitchell, P. Palmadesso,
NRL Memo Report 5673, 1985
46
Particle orbits in inner magnetosphere

• Assumptions
• DB/B is small over a gyroradius gyroperiod
• Motion of the particles of interest is
  collisionless (except if the hit the ionosphere,
  where they die)

47
Charged particle orbits, static B(for B
quasistatic and gradB/ B ltlt rg-1 )

• Fast gyration about field line
• North-south bounce due to magnetic mirror force
• Slow east-west drift due to inhomogeneous
  magnetic field
• ExB drifts due to electric fields

48
Gyration about B-line

• rg gmv/qB (MKS units)
• Wc qB/gm (MKS units) or qB/mc (cgs)
• Sub-kHz to MHz angular frequencies (2pf)
• Wc 1.76x107 B(G)/g for electrons
• 104 B(G) for protons

49
Scale of Proton Gyroradius Gyrofrequency

• 0.1 G rg(1 MeV) 10 km A (eperp/e)½
• wci 1000 rad/s f ci 160/s
• .01 G rg(1 MeV) 100 km A (eperp/e)½
• wci 100 rad/s f ci 16/s
• tN-S 1.3 s (L2) 50 gyroperiods

50
Adiabatic invariants

• General form ?pdq
• 1. Magnetic moment invariant
• gm pperp2/2mB (m qrg2/2c)
• 2. Bounce invariant J ?ppards
• 3. Longitudinal drift invariant (L shell)

51
North-South bounce motion

• Determined by pitch-angle of fast velocity vector
  at magnetic equator,
• And by energy conservation.
• If Eparallel 0, each particles parallel energy
  is converted to perpendicular energy until it has
  no more parallel momentum, then it reverses its
  parallel motion.

52
Effective magnetic mirror force

• When a very-small-size dipole moves along
  magnetic field lines of an inhomogeneous field,
  there is an effective force parallel to the
  field line that has magnitude sign
• Fparallel - m d B/ds
• where s measures arclength along the magnetic
  field. A dipole entering a region of stronger
  magnetic field thus has a retarding force on it,
  slowing its parallel motion.

53

• One may ask How can this be? The magnetic force
  on a charged particle, qvxB/c, is always
  perpendicular to v and so can do no work on the
  particle if B is constant in time.
• In fact, the particle kinetic energy,
• ½ m vz 2 ½ m vy 2 , does not change only the
  partition between vz and vy changes.
• And this change of the direction of v is due to
  the fact that the particle is not exactly at the
  position of its guiding center, so the directions
  of the field lines of B at the particle are not
  quite the same on opposite sides of the
  gyro-orbit, leading to a gyro-averaged vxB force
  that has a parallel component.

54

• The constancy of m (½ m vperp 2 ) /B during
  collisionless nonrelativistic charged particle
  motion along B, and
• the constancy of ½ m vpar 2 ½ m vperp 2 KE,
• mean that vpar can be expressed in terms of its
  value at some reference point so by
• ½ m vpar 2 (½ m vpar 2)o - m(B - Bo),
• i. e. the parallel motion is derivable from a
  potential, mB.
• (If there is also a static electric field
  parallel to the magnetic field, the effective
  potential for parallel motion of the dipoles
  generalizes nicely to mB qf .)
• When B has a minimum at some reference point so
  along each magnetic field line encircled (or
  enhelixed) by a particle, the collisionless
  parallel motion will be that of a particle in an
  effective potential well (remember, though, that
  the magnetic potential depends on the constant m,
  which is not the same for all particles !).

55
Half of Loss-cone(s) in magnetic-equator
velocity-space
Shown for no parallel electric field
56

• Particle turns around where ( if) vpar 2 0,
  where all the energy is converted to
  perpendicular energy,
• i. e. at B such that
• (½ m vpar 2)o - m(B - Bo) - q(f - f o) 0.
  
• This turning point equation, with the help of
  magnetic moment constancy
• (½ m vperp 2 ) /B (½ m vperp 2 ) o /B o ,
• specifies the turning points as where
• (½ m vpar 2)o - (½ m vperp 2 ) o (B/Bo - 1) -
  q(f - f o) 0.

57

• When there is negligible parallel electric field
  this is simply
• B /Bo 1 (vpar2 / vperp 2)o ,
• so each trapped collisionless particle mirrors,
  i.e. changes its sign of parallel velocity, at a
  value of B/Bo that depends on its pitch angle at
  the minimum of the magnetic field.
• In the reference-plane velocity space vpar o,
  vperp o, one can draw a boundary for any value
  of B1, such that particles with v perp o above
  the boundary will be trapped in the spatial
  region where B lt B1 , and those with v perp o
  below the boundary can progress to higher values
  of B than B1 if nothing else stops them first.

58
Loss regions in midplane velocity space(s) when
there is a steady parallel E field toward the
ionosphere (positive potential on field line)
trapped
Lost to ionosphere in 1 bounce
Positive potential occurs so as to reduce
electron loss rate to the (increased) ion loss
rate.
59
Same thing in midplane energy space
60
Particle gyration bounce in inner magnetosphere
From T. Tascione, Intro to the Space Environment
61
(From G. K. Parks, Physics of Space Plasmas)
Energy conservation (with E0)
ao pitch angle at mag. Equator (l 0) Bo
field strength at mag. Equator
62
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63
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64
Charged particle longitudinal drift due to
magnetic field inhomogeneity
Cross-field drift of and particles under
force F
From Parks, Physics of Space Plasmas
65
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66
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67
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68
Longitude-drift periods (from Parks)
69
Drift Rate (in terms of energy, mag. Moment,
bounce invariant, bounce period, and L)

• For static magnetic dipole, with E 0
• ltdf/dtgt - (2cLRE e /em) (3/2 - J/4et)
• with t ?ds/vy N-S bounce period,
• and J m ?vy ds bounce action integral.
• T. G. Northrop, in Radiation Trapped in the
  Earths Magnetic Field, B. M. McCormac, ed.,
  Reidel 1966

70

• For nonstatic dipole B without shear
• (but changes slow enough to preserve J and m)
• ltdf/dtgt - (2c/et)?rdq (B/Bq )(2m(H - mB -
  qF))½
• (Bq /B)( ?/?L)(rB/Bq) ½ r ?B/?L
• - ½ (2m(H - mB - qF))-½ 2m(H -qF)r ?lnB/?L rq
  ?F/?L
• with F electric
  potential
• and f longitude
  angle.
• T. J. Birmingham, Guiding center drifts in
  time-dependent meridional magnetic fields,
• Phys. Fluids 11, 2749 (1968)

71
Ring Current from drifting, gyrating
particles(Parks sec. 7.7.4, with corrections)

• (a) From guiding-center drifts
• Jgc e (ni vdrift(i) - ne vdrift(e-) )
• Sn(KE) e (KE/e) (1 cos2a) bxgradB
  /B2
• bxgradB/ B2 -3/rB if at l 0
• so Jgc -3nltKEgti ltKEgte /rB (for
  equatorial particles)
• Igc ?JgcdV /2pr - 3Etot/(2pr2B)
• (b) From pressure gradient of gyrating particles
• JgradPperp xB grad (nltKEgti ltKEgte perp.)
• IgradPperp ?rdrdl grad (nltKEgti ltKEgte
  perp.)/B
• Etot/2pr2B

72

• so this (b) current reduces the average net ring
  current magnetic field by about 1/3. The net
  ring current then reduces the magnetic field at
  the magnetic equator at 1 RE by
• DB/B - (2/3) Etot/Emag ,
• where Emag is the volume-integrated energy in
  magnetic field.
• See more general derivation in R. L. Carovillano
  J. J. Maguire, in Physics of the Magnetosphere,
  (Carovillano et al, eds), Reidel, 1968.
• Ring current usually peaks at 4-5 RE (quiet) at
  2-4 RE (storm)
• Mean proton energy 85keV (90 are in 10 - 250
  keV)
• Quiet-time ring current density 10-8 A/m,
• increased by factor of several during storms.
• See Tascione sections 5.4.3, 5.9, 5.10

73
Typical energy spectrum of energetic protons
74
Power delivered by solar wind/ CME

• Power Current x ?(-vxB)dl
• Current varies as wc, i.e. as B
• Power varies as B2v sin4(q/2)
• where
• q angle of IMF from northward
• sin 0 for northward IMF
• sin 1 for southward IMF
• J. K. Alexander, L.F. Bargatze, J. L. Burch et
  al.,
• Coupling of the solar wind to the
  magnetosphere
• in
• Solar Terrestrial Physics
• D.M. Butler K. Papadopoulos, eds. NASA, 1984
• Tascione, sections 3.7, 5.8, 5.10

75
Energy injection into ring current

• Empirical approximate formula for ring-current
  addition rate in terms of Dst and ring-current-
  enhancement lifetime t
• UR(J/hr) 4x1010(dDst/dt Dst/ t)
• (Tascione sec.5.10)
• See Akasofu Sp. Sci Rev, 28, p160, 1981 for a
  related formula         Dst 60(log
  epsilon - 18)2 25
• where epsilon B2v sin4(q/2)

76
Nov. 6, 2001 event

• Southward B component 80 nT
• Unusually sharp CME shock with speed gt1000km/s
• Nearly perpendicular shock
• L8 SEPs showed sharp rise in on shock arrival
• L3 14-25 MeV protons arrived minutes before
  shock
• and were trapped when shock arrived
• via front-side cusp entry
• stayed trapped til Oct 03 storm detrapped them
• 3-20 MeV electrons enhanced at first, but
• deep dropout of total gt1MeV electron flux at
  L3-8,
• with few-days recovery time

77

• Mary Hudsons PIC particle follower, riding on
• Fedder-Lyons-Mobarry MHD code,
• followed particles from ACE input data
• Cluster data (Morikis Kistler, UNH)
• Cluster apogee 20 RE, perigee 4 RE, every 48
  hrs
• 50 hr orbit, 2hrs in magnetosphere at 4RE
• Sampex data 1-3 MeV electrons, 10-20 MeV
  electrons

78
Stochastic Injection of Energetic Particlesfrom
Bow Shock andTailward reconnection region

• Nonadiabatic because gyroradius B scale-length
  locally
• Timescale t varies as m5/4e-1/2
• Flux density injected varies as density at low
  densities
• M. G. Rusbridge, Non-adiabatic effects in
  charged-particle motion near a neutral line,
  Plasma Physics 19, 1087 (1977) and
• Non-adiabatic charged particle motion near a
  magnetic field zero line, Plasma Physics 13, 977
  (1971)
• W. Peter N. Rostoker, Theory of plasma
  injection into a magnetic field, Phys. Fluids
  25, 730 (1982)
• J. Chen P. J. Palmadesso, Chaos and nonlinear
• dynamics of single-particle orbits in a
  magnetotail-like magnetic field, JGR 91, 1499
  (1986) errata 91, 9025 (1986)

79
Particle Diffusion

• Dominated by field fluctuations in storm
  conditions.
• Lee/Sydora Gyrokinetic Code calculates for
  Tokamaks.
• Diffusion model
• W. N. Spjeldvik, Consequences of the duration
  of solar energetic particle-associated magnetic
  storms on the intensity of geomagnetically
  trapped protons, in Modeling Magnetospheric
  Plasma, T.E. Moore J.H. Waite, eds. AGU 1988
• J.M. Cornwall, Radial diffusion of ionized
  helium and protons a probe for magnetospheric
  dynamics JGR 77, 1756 (1972)
• df/dt L2d/dL (DLLL-2df/dL) - Af Gm-1/2df/dm
• A charge exchange factor, G Coulomb slowing
• DLL(L, m) given in Cornwall (1972),
• assumes power-law ( n-2) spectrum of
  fluctuations in B and E.

80
Flow dynamics of charge-neutralized plasma fluid

• ?t UgradU (1/rmo)(Bgrad)B - grad(B2/2)
  - (1/r) divP g
• P pressure tensor pperp I (ppar -
  pperp)bb
• (div P )perp gradperp pperp - (ppar -
  pperp)(bgrad)b
• (div P )par (bgrad)ppar (ppar -
  pperp)divb
• div P gradp for isotropic pressure
• ?t Ugrad (pperp/rB) 0
• ?t Ugrad( pparB2/r3) 0
• G.F. Chew, M.L. Goldberger, F.E. Low, Proc.
  Roy. Soc (Lon.) A236, 112 (1956)
• N.A. Krall A.W. Trivelpiece, Principles of
  Plasma Physics, McGraw Hill 1973

81
Magnetosphere Simulation

• Particle codes, incl. gyro-averaged particle
  followers (e.g. Mary Hudsons at NASA R. M.
  Winglee code at UW)
• Fluid (MHD) codes
• Fedder-Lyon-Mobarry code (NRL)
• BATSRUS (U. Michigan)
• Spicer code(s) Odin etc.
• Modified MHD Winglee
• Hybrid (particles and MHD) codes
• Rice MSM code
• Kazeminezhad 2D code

82

• Models are available for community use
• CCMC http//ccmc.gsfc.nasa.gov/
• UCLA http//www-ggcm2.igpp.ucla.edu/
• Source codes in public domain
• GEDAS (Japan, T. Ogino) (Japan, T.)
  http//gedas22.stelab.nagoya-u.ac.jp/simulatio
  n/jst2k/hpf02.html
• BATSRUS http//csem.engin.umich.edu/
• NRL http//www.lcp.nrl.navy.mil/hpcc-ess/software
  .html
• FCTMHD3D (C.R. DeVore)
• AMRMHD3D (P. MacNeice)
• Zeus 3D MHD (Michael Norman) http//zeus.ncsa.uiu
  c.edu8080/lca_intro_zeus3d.html
• CFD Codes http//icemcfd.com/cfd/CFD_codes.html

83
Fedder-Lyon-Mobarry (FLM) Codedistorted
spherical coord. grid
84
MHD eqns as solved in FLM code
J. G. Lyon, Numerical methods used, Proc.
ISSS-7, 26-31 March 2005
85
FLM Code

• Does not include particle acceleration (since
  its an MHD code)
• but does show overall energetics of CME coupling
  for southward IMF,
• and shows very weak coupling for northward IMF.
• Coupling is by fast magnetosonic wave propagation
  from magnetopause.
• Shows Poynting vector energy flow from these
  waves.

86
BATS-R-US Code (U. Mich.) Block-Adaptive-Tree
Solarwind Roe-Upwind Scheme)

• Gombosi et al
• 3D MHD, Eulerian xyz grid (x toward sun)
• Block-adaptive mesh refinement
• Cell-centered finite volume method
• Upwind-differencing Riemann solver
  (Powell 1994)
• Efficiently parallelized
• High computation/communication ratio

87

• Runs on Sun, SGI shared memory, Cray T3D T3E,
  and IBM SP2
• Simulation box typically 192 RE wide,
  192 to -384 RE in x direction
• Cell size typically .25 RE to 32 RE
• Inner boundary at 3 RE (no mass flow across it)
  coupled along assumed dipole B lines to finite
  tensor conductivity, height-integrated ionosphere
  layer at 1 RE M. L. Goodman, Ann. Geophys. 13,
  843 (1995)
• Dipole inner field separated off as in Tanaka,
  JGR 100, 12057 (1995)

88
BATSRUS simulation of outermost closed B lines,
for Parker spiral IMF
89
Winglee modified MHD code

• R.M. Winglee, Regional Particle simulations and
  Global Two-fluid Modeling of Magnetospheric
  Current Systems, in
• J. L. Horowitz et al., Cross Scale Coupling in
  Space Plasmas, QC 809.P5 C76, 1995
• Uses a 2-fluid modified MHD set of equations
• Gets the injection of currents plasma across
  B-field lines

90
Rice MSM Code
91
Rice MSM Code

• E. C. Roelof, B. H. Mauk, R. R. Meier, K. R.
  Moore, R. A. Wolf, Simulation of EUV and ENA
  magnetospheric images based on the Rice
  Convection Model,
• in Instrumentation for Magnetospheric Imagery
  II, SPIE 1993.
• (ENA energetic neutral atom)
• Streamlined version of RCM MSM (magnetic
  specification model), has non-self-consistent E
  field from phenomenological convection patterns.

92
F. Kazeminezhad new code

• 2D hybrid
• Triangular
• finite-element
• grid

93
MagnetoTail
94
Magnetic Reconnection
95
Modeling driven reconnection
96
2-D Compressible Resistive MHD Simulation
ofDriven Reconnection

• S. -P. Jin W. -H. Ip, Phys. Fluids B3, 1927
  (Aug. 1991)
• Plasma beta at inflow boundary of simulation box
  initially 0.1
• Alfven Mach of inflow MA 0.15 (for -.5 lt z
  lt.5), tapering to 0 at z gt1
• High Lundquist Number 400 - 2500 (very low
  resistivity)
• Lundquist Number ratio of JxB force to
  resistive mag. diffusion force
• Initial Bz(x) profile half sine wave -w lt x lt w
  (w lt1), 1 for x gt w
• (odd function of x)
• Initial state in pressure balance
• Grid resolution in x Dx increases 13 every
  step.
• Grid concentrated in center near x 0.
• Time in units of Alfven-wave x-crossing time.
  Sim. 40 units.
• Implicit integration scheme Y. Q. Hu, J. Comp.
  Phys 84, 441 (1989)

97
B lines, v vectors, DT(), Dr()
Time ?
S-P. Jin W-H. Ip. 2D compressible MHD sim. ,
PhysFluids B 3, 1927 (1991)
98
PIC simulation of particle orbits near a magnetic
reconnection line

• H-J. Deeg, J.E. Borovsky N. Duric, Phys Fluids
  B 3, 2660 (1991)
• Geometry and results shown in following slides

99
Region where magnetic insulation fails, i.e
where B is weak
H-J. Deeg, J.E. Borovsky N. Duric, Phys Fluids
B 3, 2660 (1991)
100
Geometry for PIC simulation of particle
acceleration near reconnection region
H-J. Deeg, J.E. Borovsky N. Duric, Phys Fluids
B 3, 2660 (1991)
101
Proton orbits in views 1 2
102
Proton orbit in views 2 3
103
Energy gain of protons entering near neutral point
H-J. Deeg, J.E. Borovsky N. Duric, Phys Fluids
B 3, 2660 (1991)
104
Final proton energy vs initial proton energy, for
protons initially incoming near neutral point
H-J. Deeg, J.E. Borovsky N. Duric, Phys Fluids
B 3, 2660 (1991)
105
Turbulence in B-line reconnectionMatthaeus
Lamkin, PhysFluids 29, 2513 (1986)
Contours of constant J
Magnetic field
Contours of constant vorticity
Fluid stream-lines
106
Disturbed magnetotail reconnection at current
sheet can launch plasmoids relax (as well as
accelerating particles forward backward)
E. W. Hones, Sci. Am. March 1986
107
Some references on field-line reconnection

• Observations by Cluster satellite
  A. Runov et al.,
  Geophys. Res. Lett. 30, 1579 (2003)
• Observations by WIND satellite
  T. D. Phan et al.,
  Nature 404, 848 (2000)
  M. Oieroset, R. P. Lin et al., Nature
  412, 414 (2001)
• 3D PIC simulation
• P.L. Pritchett F. Coroniti, JGR 109, A
  01220 (2004)
• 2D simulation with guide field normal to
  plane P. L.
  Pritchett (UCLA) Onset Saturation of
  Guide-field Magnetic Reconnection, Phys. Plasmas
  12, 062301 (June 2005)

108
More references on field-line reconnection

• Particle acceleration orbits
• H-J Deeg, J.E. Borovsky N. Duric (LANL),
  Particle acceleration near X-type magnetic
  neutral lines, Phys. Fluids B 3, 2660 (1991)
• Electric field enhancements (EFE)
• J. D. Scudder F. S. Mozer, Electron
  demagnetization and collisionless magnetic
  reconnection in bltlt1 plasmas, Phys. Plasmas 12,
  092903 ( Sept. 2005)
• Role of microinstabilities (anomalous
  resistivity)
• M. Ugai L. Zheng, Conditions for fast
  reconnection mechanism in 3D Phys. Plasmas 12,
  --- ( Sept. 2005)

109
Satellite sensors

• Radiation Belt Mappers
• GOES (ESA)
• Cluster, Vortex
• Doublestar
• Polar
• Image
• Geotail (Japan)
• ISEE1-3, IMP1-8 other former sats with elderly
  data
• Ionospheric satellites measuring energetic
  particles DMSP, SAMPEX etc.
• Upcoming NPOESS NPP

110
Living With A Star Research Network
Pole Sitter
Solar Dynamics Observatory
L1 Solar Sentinel
Ionospheric Mappers
L2
Radiation Belt Mappers
Distributed network of spacecraft providing
continuous observations Geospace Dynamics
Nework with constellations of smallsats in key
regions of geospace.
111
How to find satellite orbit info ( related data)

• http//pwg.gsfc.nasa.gov/orbits
• /menu_orbits.html
• Orbits for Wind, ISTP, Cluster, Image, Polar

112
Radiation Belt Mappers
Understand origin and dynamics of the radiation
belts. Determine time space-dependent
evolution of penetrating radiation during
magnetic storms. First Element multiple
spacecraft in 3 petal equatorial orbits in-situ
measurements. Second Element Add higher
latitude coverage.
113
GOES description

• GOES (Geostationary Operational Environmental
  Satellites, NOAA/NESDIS)
• 2 spacecraft at 75deg W and 135deg W, one at
  98deg W and/to 108deg W, moved with season.
• 35,600 km equatorial orbit, spin axis parallel to
  earths spin axis. Telemetry to NOAA ERL,
  Boulder.
• measuring
• solar X-rays,
• B field at satellite,
• high energy particles, via SEM (Space Environment
  Monitor).
• SEM has
• (a) Total Energy Detector (TED)- intensity of
  energetic particles 0.3-20 keV in 11 bands
• (b)Medium-Energy Proton Electron Detector
  (MEPED) - 30 keV-60MeV
• (c) High-Energy Proton Alpha Detector (HEPAD) -
  370 MeV- gt850 MeV.

114
Cluster Vortex
115
Cluster Doublestar (DSP)
116
Cluster data (Morikis Kistler, UNH)

• Cluster (ESA NASA, 2000)
• Cluster apogee 20 RE, perigee 4 RE, every 48 hrs
• 50 hr orbit, 2hrs in magnetosphere at 4RE

117
Some Cluster results

• Cluster has now proven the existence of The
  Kelvin-Helmholtz instability as an important
  solar wind entry process.
• These large-scale vortices could lead to
  substantial entry of solar wind to populate the
  Earth's magnetosphere. (Tai Phan, UCB SpSciLab.)

118
Polar orbit (http//pwg.gsfc.nasa.gov/orbits/aaar
eadme_polarpar.html
The POLAR orbital parameter plots show the radial
distance, eccentric dipole (ED) magnetic local
time (MLT), and eccentric dipole L-shell value.
The darker segments correspond to times when one
of the magnetic footpoints (traced down to 100 km
altitude using the T89, Kp3-,3,3, model) falls
in one of the following regions cusp, cleft, or
auroral oval.
119
Polar observation of an event

• Images in visible light from the Polar
  satellite's Visible Imaging System compares the
  northern auroral regions on May 11, 1999, and a
  more typical day on November 13, 1999. Credit
  University of Iowa/NASA.

120

• Polar, contd
• May 11, 1999 event solar wind flux dropped a lot
• produced an intense "polar rain" of electrons
  over one of the polar caps of Earth.
• Electrons flow unimpeded along the Sun's magnetic
  field lines to Earth and precipitate directly
  into the polar caps, inside the normal auroral
  oval.
• Such a polar rain event was observed for the
  first time in May 1999 when Polar detected a
  steady glow over the North Pole in X-ray images.
• Jack Scudder, U. Iowa, PI for the
• Hot Plasma Analyzer on NASA's Polar spacecraft.
  Scudder and Don Fairfield of Goddard had
  predicted the details

121

• In parallel with the polar rain event, Earth's
  magnetosphere swelled to five to six times its
  normal size.
• NASA's Wind, IMP-8, and Lunar Prospector
  spacecraft, the Russian INTERBALL satellite and
  the Japanese Geotail satellite observed the most
  distant bow shock ever recorded by satellites.
• SAMPEX spacecraft reveal that in the wake of this
  event, Earth's outer electron radiation belts
  dissipated and were severely depleted for several
  months afterward.

122
Image Satellite ENA sensors
123
Image website (Southwest Research)

• http//pluto.space.swri.edu/IMAGE/
• HENA D. G. Mitchell and HENA team, the Johns
  Hopkins University Applied Physics Laboratory
• MENA C. J. Pollock and J.-M. Jahn, Southwest
  Research Institute

124
HENA Images of ENA fluxes during the July 15-16
2000 Geomagnetic Storm
125
Geotail (Japanese space program)

• Instruments
• Solar wind, hot plasma, composition analyzers,
  
• directional data on electrons/protons/helium
  above 20keV, protons above 400keV, electrons
  above 120kev, B field, etc.
• http//www-istp.gsfc.nasa.gov/istp/geotail/geotail
  _key_parameters.html

126
DMSP Satellites

• Orbits circular, sun-synchronous, polar, 850km
  alt.
• 98.7 deg inclination, period 101 min., revisit
  time 6 hrs.
• Global coverage _at_ 12hrs each satellite
• Communications S-band, about 3 MBPS in 1995
  maybe more capacity now.
• Design life 3-5 yrs.
• Block(group) 5D-2 (5 sats) launched 1991-98,
  earlier ones presumably now down or inoperative
• Block 5D-3 (5 more satellites, S16-20, built by
  Martin Marietta) launched 1999-06 Block 6
  beginning 04.

127
DMSP, contd.

• Relevant sensors for space weather
• SSI/ES Ionospheric Plasma Drift/Scintillation
  Monitor 4 sensors monitoring ion electron
  densities, temperatures, drift velocities of
  ions, and plasma irregularities above the F
  region.
• SSI/ES-2, 3 are enhanced versions, flown since
  94 and 99.
• SSJ/4 Precipitating Electron/Proton Spectrometer
• SSB/X X-ray detector array - x-rays from earths
  atmosphere.
• Upgraded version SSB/X-2 can also detect gamma
  ray bursts.
• SSM magnetometer measures B-field fluctuations
  due to hi-latitude ionosphere currents.

128
Sampex (GSFC)

• Solar Anomalous and Magnetospheric Particle
  Explorer (Medium Earth Orbit).
• First of NASA's Small Explorer (SMEX) missions.
• Typical orbit 520 x 670 km, 82 deg inclination
• Energy, composition and charge states of
• (1) cosmic rays
• (2) solar energetic particles
• (3) magnetospheric electrons trapped by the
  Earth's magnetic field).
• http//www.astronautix.com/craft/sampex.htm
  etc.
• Sampex data 1-3 MeV electrons, 10-20 MeV
  electrons
• PET Proton-Electron Telescope energy spectra of
  electrons from 0.5 to 30 MeV, and of H and He
  from 20 to 200 MeV/nuc
• http//www.srl.caltech.edu/sampex/

129
Upcoming NPP NPOESS

• The NPP satellite is scheduled for launch in 2007
  into a circular sun-synchronous polar orbit at a
  nominal altitude of 824 kilometers and a 1030
  a.m. descending node.
• This orbit provides a 16-day repeat cycle (8-day
  quasi-repeat), similar to that of the EOS
  satellites.
• Ref.The NPOESS Preparatory Project Architecture
  and Prototype Studies (Aerospace Corp. website)
• The National Polar-orbiting Operational
  Environmental Satellite System (NPOESS)
  represents a convergence of systems previously
  operated by the Department of Defense and the
  National Oceanic and Atmospheric Administration
  (NOAA).
• Scheduled for launch in 2009, it will support a
  broad range of activities in global environmental
  monitoring, meteorology, and climatology.

130
NASA CDAW at GMU, Mar. 2005

• http//cdaw.gsfc.nasa.gov/geomag_cdaw
• /register/wg2_participants.html
• Names contact information of researchers in
  magnetosphere dynamics data
• http//solar.scs.gmu.edu/meetings/cdaw/data/
• cdaw2/wg2_datatable.htm
• Data files for selected events, from several
  satellite instruments (click on data first
  WG2 data table)

131
Magnetosphere Homework Assignment, 10/25/05

• 1. Look up typical magnetotail storm-period data
  (Bfield strength, particle densities, particle
  temperatures) from, e.g., IMP 8 data.
• 2. Use these data along with Fig. 5.6 of Tascione
  to estimate the order of magnitude of
• (a) tailward speed of ejected plasmoid (km/s)
• (b) directed particle energy of tailward-ejected
  plasmoid (J)
• (c) kinetic power loss (mean particle energy loss
  rate) during plasmoid ejection (W)
• (d) magnetic energy stored in magnetotail (J)
• 3. Use ACE or WIND data to estimate the typical
  order of magnitude of CME ram pressure rv2 (J/m3)
  and of CME-enhanced power delivery to day-side
  magnetopause (W), for southward Bz -80nT and
  twice the typical Parker-spiral westward By. Is
  this pressure much bigger than the magnetic field
  pressure? Estimate the power (W) delivered into
  the magnetopause by such a CME.
• 4. Tascione problem 5-4
• 5. Tascione problem 5-5
• 6. Tascione problem 5-12

132
CSI 769 Class Project, fall 2005Magnetosphere
portion

• This part of the project focuses on the
  energetics of the Halloween 03 CME-induced
  changes in the magnetosphere, by doing five short
  order-of-magnitude calculations based on
  retrieved data.
• 1. From Wind or ACE data, estimate the peak CME
  (particle magnetic) pressure increase on the
  bow shock, and its rise rate during the Halloween
  03 event.
• 2. From earthbound magnetometer data, e. g. Dst,
  estimate
• (a) the time delay of surface DB after the
  bow-shock energy delivery, and
• (b) the energy and power delivery to the
  enhanced ring current during the storm.
• (c) If the time delay is related to propagation
  of a disturbance at near the Alfven speed, use
  the magnitudes of B and estimated plasma
  densities to compare the time delay to that of
  the most direct delivery route.
• (d) Is the ratio of estimated change in
  ring-current energy (volume integral of DKE
  D(B2/2mo)) to CME energy (magnetopause-intersectin
  g volume integral of energy density in the CME on
  bow-shock arrival) of order unity or ltlt1?
• 3. (a) Based on your estimates of magnetospheric
  DB due to enhanced ring current and its risetime,
  estimate the peak E fields (mV/m) induced, and
  compare them to the corotation E field.
• (b) Give an estimate of the peak E field on the
  topside of the ionosphere, say at 500km altitude,
  and the ExB drift speed E/B (km/s) at 60degrees
  magnetic latitude.
• 4. Use geotail data during the storm to estimate
  the peak change in magnetic energy storage in the
  magnetotail volume, and its buildup rate.
  Compare these numbers with the estimated
  frontside energy arrival by the CME.
• 5. Use NOAA energetic-particle flux data etc. to
  estimate the change in total energy in MeV (and
  higher-energy) protons transported by the storm
  to the auroral ionosphere, and compare this with
  the other energies calculated above.
• Part of the data is collected at
  http//solar.scs.gmu.edu/meetings/cdaw/Data_maste
  r_table.html

133
Some textbook errata

• Tascione
• Eq. 1.17 (not ) after first term
• Eq. 1.33 B(vector)x gradient of scalar B
  (magnitude of vector B), not of vector B.
• Fig. 2.6 protons dont arrive with predominantly
  45 degree Incidence, even though B
  does. Water-sprinkler effect.
• p. 35 U components theta phi here are
  interchanged from the usual (i.e. Jackson).
• p.38 Eq 3.28 factor of d is ignored in the final
  proportionality and is treated as constant in
  3.29, but reappears as Lo2 in 3.30.
• p.44 Eq. 4.9 Z on left, not H.
• Eq. 4.10 B on left, not H.
• p. 59 Eq. 5.20 sign (not -) in numerator.

134
Some textbook errata, contd.

• Parks
• p. 56 Eq. 3.36 3.37 Confused notation. r and
  lambda are component indices, not independent
• variables.
• p. 72 Eq. 3.73 Careful! The rotation axis is not
  the magnetic axis. See Tascione Eqs 4.1 4.2.
• p. 106, first line of sec. 4.55.6 current
  density, not currents. Current is meaningful for
  single charged particle
  in motion (Iqv). Current density is not
• p. 139 problem 18 dimensional error in formula.
• p. 156, top two eqns either one or the other
  (not both, unless gamma 1).
• p. 249 Eq. 7.20 see eq. 7.57 when p is
  anisotropic.
• p.255 below eq. 7.39 outward out of paper
  (as looking down from N pole), not radially
  outward
  from earth.
• p. 259 after eq. 7.53 del parallel plus del
  perp. (not -)
• p.261 after eq. 7.65 B is not necessarily given,
  just static.
• p.264 after eq. 7.70 Br vanishes at the magnetic
  equator (only).
• p.265 eq. 7.74 sum over species! Epsilon is
  the energy-density of all the drifting particles
  (e i).
• p.267 Eq. 7.82 delta BT/Bs on left side, not
  delta BT.
• p. 314, before sec. 8.2.2 Plasmas in steady
  state do support free charges, but mainly at or
  near their boundaries. Like a
  pretty-good conductor, they move the net charge
  to the surface.