Post on 18-Dec-2015
Bastille Day 2000 Solar Energetic Particles Event: Ulysses observations at high
heliographic latitudes
M. Zhang
Florida Institute of Technology
102
100
10-2 Ulysses 14-19 MeV p
Earth (GOES) 15-44 MeV p
102
100
10-2
Inte
nsi
ty (
arb
. un
it) Ulysses E>92 MeV p Earth (GOES) E>100 MeV p
10-2
100
102
Ulysses 3-5 MeV e Earth (SOHO) 2.6-6 MeV e
1200
1000
800
600
400
Vsw
(km
/s) Ulysses Solar wind
Earth (IMP-8) Solar wind
210209208207206205204203202201200199198197196195Day of 2000
3.0
2.0
1.0
0.0
|B| (
nT
)
Ulysses Mag Earth (ACE) Mag
FlareShock at Earth
Flare
Earth
Ulysses
Ulysses fieldfootpoint
CME
Earth fieldfootpoint
Ulysses at 3.AU 62oS on July 14, 2000
Location, Location, Location
10-5
10-4
10-3
10-2
10-1
100
100
MeV
p F
lux
1086420 Time (day)
(if no perp)
-90
-45
0
45
90
Lat
itude
-180 -135 -90 -45 0 45 90 135 180Longitude
To 1 AU
2.0
1.5
1.0
0.5
0.0
-0.5
Ani
sotr
opy
1086420 Time (day)
10-5
10-4
10-3
10-2
10-1
100
100
Mev
p fl
ux
1086420Time (day)
to 1 AU centered
2.0
1.5
1.0
0.5
0.0
-0.5
Ani
sotr
opy
1086420Time (day)
-90
-45
0
45
90
Lat
itude
-180 -135 -90 -45 0 45 90 135 180Longitude
To 3 AU
360
270
180
90
0
(
de
gre
e)
199.0198.5198.0197.5197.0196.5
N axis
B field; Anti B field; Particle flow
0.01
0.1
1
A1
199.0198.5198.0197.5197.0196.53
2
1
0
C0
(co
un
t/se
c)
199.0198.5198.0197.5197.0196.5Day of 2000
40-90 MeV protons
270
225
180
135
90
45
0
Ang
le in
spa
cecr
aft s
pin
plan
e (d
egre
e)
198.0197.5197.0196.5Day of 2000
Observed flow direction for ~40-90 MeV protons Expected for flow along magnetic field lines Expected for 3-d diffusion with per/par=0.25
-180
-90
0
90
180
De
gre
e
257.5257.0256.5256.0
257.5257.0256.5256.0Day of 2000
0.012
4
0.12
4
1
A1
10-2
10-1
100
C0
(c/s
)
257.5257.0256.5256.0Day of 2000
Ulysses at 2.7 AU, 70oS
• Small latitude gradient of cosmic ray
• Recurrent cosmic ray modulation effects by CIR’s propagate to the polar regions above 80o
• Energetic articles accelerated by CIR shocks appear in the polar regions above 80o
Evidence for easy latitudinal transport of energetic particles in the heliosphere
Ulysses observations during 1994-1995 solar minimum:
Ulysses observations during 2000-2001 solar maximum:
• Zero latitude gradient of cosmic ray
• Solar energetic particles from same solar events are observed by spacecraft (Ulysses and IMP-8) in large latitude and longitude separations.
How do the solar energetic particles get to high latitudes?
1. Direct magnetic connection to particle sources (particle transport along field lines)
• Extended particle source in the corona
• Field lines connect to low latitude
2. Cross-field transport
• Anything is possible
)]22cos()cos(1[)( 22110 AACC
Ulysses COSPIN/HET
Sectored 40-90 MeV Proton Rates
Possible sources of first-order anisotropy perpendicular to magnetic fields
1. Compton-Getting effect:
A1< 4%E>40 MeV, < ~2Vsw = 600 km/s
No
2. B x Gradient (drift effect):
A1 is small
( rg=0.003 AU)
Magnetic polarity
No
3. Diffusion:
Yes
v
VA sw
)1(21
fB
Brf
B
B
vA g
A ln3
1ln1
ffv
A ln3
1ln
11
Conclusion
• Easy particle transport across heliographic latitude
• Perpendicular diffusion flow was observed
•
• Implication to particle scattering theory
anisotropy ln nofor fbA
25.0||