SHINE SEP Campaign Events: Detailed comparison of active regions AR9906 and AR0069 in the build-up to the SEP events of

21 Apr 2002 and 24 Aug 2002

D. Alexander, A. Coyner, A. G. Daou, R. Liu

Rice University

The SEP signatures of the solar flares occurring on 21 Apr 2002 and 24 Aug 2002 show marked differences in their compositions above 10 MeV/nucleon yet at the Sun the events themselves show very little differences in either their hard X-ray chromospheric emission or their coronal signatures. The purpose of this and related posters is to look at the prior evolution of the SEP-event active regions to look for possible signatures in the ambient corona, magnetic connectivities (within the active region, within large-scale closed field, and the open field distributions), and flare/activity history which may differentiate the solar conditions which led to such disparate particle signatures at 1 AU. In this paper, we summarize the results from the detailed data analyses and discuss their implications for SEP events.

SEP COMPOSITION FOR CAMPAIGN EVENTS SHOW DIVERGENCE IN Fe/C RATIO ABOVE 10 MeV/NUCLEON

Tylka et al., 2004

Campaign Events not that dissimilar at Sun

NOTE:• Confined to emission at Sun• HXR emission presumed dominated by electrons• HXR emission confined to ‘closed’ structures

APR 21 2002

AUG 24 2002

Campaign Events not that dissimilar at Sun

APR 21 2002

AUG 24 2002

Event Comparison

Qualitatively, these two flares are very similar at X-ray energies.

Both events have roughly the same soft X-ray magnitude and evolution- Apr 21 has broader SXR profile

-more energy injection? [Aug 24 partially occulted]

Both show development of large-scale curvilinear arcade (typical of large flares)

Both display high energy (hot?) coronal source with complementary emission in TRACE

Both show outward-moving loop structures near start of flare- 120 km/s for Apr 21 and ~60 km/s for Aug 24

Discussion Points from 2003

•Need to determine relationship of seed population to shock accelerated population

Shock spectra/abundances reflect flare generated particle spectra Shock selectively accelerates part of total particle distribution

• Solar Conditions What role does the magnetic topology have in differentiating the

IP influence of these two events? Do the event-producing active regions show differences in their activity and how does this activity relate to the magnetic topology?

“events like 2002 August 24 are produced by quasi-perpendicular shocks, operating on a seed population containing suprathermal ions from flare activity. These flare suprathermals could be remnants from earlier flare activity or come from the associated flare, if open field lines connect the flare site to the shock front.” Tylka et al. (2004)

NOAA Active Region Maps

NOAA Active Region Maps for the needed time periods. These are provided for reference as a number of active regions are referred to in this poster particularly AR 9906 and AR 0069 which are the active regions.

Global Field

Global field lines implemented by the PFSS when the active regions investigated were on the disk center. Open field lines are indicated by pink and green lines for different polarities Left: AR9906, 18-Apr-2002 00:04:00; Right: AR0069, 18-Aug-2002 00:04:00.

Liu et al. poster

See also Nitta (SHINE 2003) & Nitta et al. (2003)

Local Field

Field lines starting from a box centered by the active region investigated. Open field lines are indicated by pink and green lines for different polarities. Left: AR9906; Right: AR0069.

Liu et al. poster

EUV Corona: April 15-21Coyner et al. poster

• Evidence for open field regions shown in field extrapolation

• As AR 9906 proceeds toward the limb the connections to AR9902 intensify greatly while connections to 9907 become less evident.

EUV Corona: August 17-24Coyner et al. poster

• In the August data, the connections between active regions are shorter in length but appear to be more numerous

• As AR 0069 progresses to the limb only the connections to AR 0067 persist. This connection also appears to weaken as time progresses.

EUV Corona: August 17Inter-region interaction

Coyner et al. poster

01:48

01:48 06:48 15:24 21:24

EUV Corona: AugustExpanding Loops

CME Speed Histogram

Comparative histogram of April (yellow) and August (blue) CME’s binned by speed.

Coyner et al. poster

April 14-21, 2002Mean Speed: 472 km/s (511)

August 17-24, 2002Mean Speed: 549 km/s (573)

GOES HistoryDaou et al. Poster

0

2

4

6

8

10

12

14

C1 C3 C5 C7 C9 M2 M4 M6 M8 X1 X3

GOES CLASS

FL

AR

E N

UM

BE

R

15-21 APRIL 2002AR9906

18-24 AUGUST 2002AR0069

Flare Size Distributions

CampaignEvents

APRIL14 flares (12 < C3)

AUGUST52 flares (14 > M1)

Daou et al. Poster

APRIL FLARE DISTRIBUTION

AR9906

AUGUST FLARE DISTRIBUTION

AR0069

INTERPLANETARY DATA (WIND)

Liu et al. Poster

AUGUST 26-29APRIL 23-27

SummaryApril 14-21 August 17-24 Comments

Magnetic Field

• Large-scale closed field connections to distant AR• W edge dominated by open field

• Several connections to nearby ARs (some forming during this time)• No open field

• Possibly important for seed population studies.• Open field not connected to ACE @ event

Coronal Evolution

• Small-scale brightenings• Localized heating • Large-scale loop expansion

• Energized closed fields need to reach shock region and contain flare particle

CMES (excl. event)

• 48 CMEs <v> = 472 km/s • 54 CMEs <v>=549 km/s• August corona slightly more energetic

Flares (excluding event)

• 13 Flares

• Most occur close to open field

• 51 flares

• Most confined to AR kernel

• August far more productive of flares and flare/particles in build-up to Aug 24.

IP Morphology

• Shock at 1AU @ 51 hours• ICME(?) signature @ 78 hours

• Shock at 1 AU @ 58 hours• 1st Fluxrope @ 61 hours• 2nd Fluxrope @ 73 hours

• Shocks: see Tylka, Cane• Different morphologies at 1 AU might reflect different structure at Sun (see Raymond et al.)

12 < C3

1 M1

16 < C3

13 > M1

Conclusions + Relevance?April

• Open field provides access to IP space but not necessarily to ACE• Flares have access to open field but are mostly small• Direct injection of flare particles to shock for Apr 21 event depends

on longitudinal extent of shock.

August

• Closed field multi-AR topology• Significant large-flare productivity• Evidence of expanding closed-structures• Long-term trapping of flare particles could provide seed population

Fin