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||