Photospheric Sources of Very Fast (>1100km/s) Coronal Mass Photospheric Sources of Very Fast (>1100km/s) Coronal Mass EjectionsEjections

Recent studies show that only very fast CMEs (> 1100 km/s) are capable of producing strong Recent studies show that only very fast CMEs (> 1100 km/s) are capable of producing strong geomagnetic storms (Dst < -150nT). BIG QUESTION: Where these very fast CMEs come from? We analyzed geomagnetic storms (Dst < -150nT). BIG QUESTION: Where these very fast CMEs come from? We analyzed photospheric sources of 45 very fast CMEs and distinguished four different types of specific magnetic photospheric sources of 45 very fast CMEs and distinguished four different types of specific magnetic configurations associated with them: i) delta-configurations (47%), ii) magnetic complexes (22%), iii) “tadpole” - configurations associated with them: i) delta-configurations (47%), ii) magnetic complexes (22%), iii) “tadpole” - shaped sunspots (18%) and iv) quiescent filaments located near active regions (13%). Here we briefly discuss the shaped sunspots (18%) and iv) quiescent filaments located near active regions (13%). Here we briefly discuss the first three types of magnetic configurations.first three types of magnetic configurations.

Vasyl Yurchyshyn Seiji Yashiro Nat Gopalswamy

Big Bear Solar Observatory Catholic University of America NASA/GSFC

CME projection speed is related CME projection speed is related to the intensity of Bz in to the intensity of Bz in interplanetary ejecta:interplanetary ejecta:

In turn, the intensity of the In turn, the intensity of the southward Bz largely determines southward Bz largely determines the intensity (Dst Index) of a the intensity (Dst Index) of a geomagnetic storm:geomagnetic storm:

1. Complex Delta Spots (11 - X, 8 - M & 2 – C 1. Complex Delta Spots (11 - X, 8 - M & 2 – C flare)flare)Date Speed Coord NOAA Area Length Date Speed Coord NOAA Area Length

FlareFlare

2. Tadpole-Shaped ARs (2 - X, 5 - M & 1 – C 2. Tadpole-Shaped ARs (2 - X, 5 - M & 1 – C flare)flare)

Date Speed Coord NOAA Area Length Date Speed Coord NOAA Area Length FlareFlare

Date Speed Coord NOAA Area Length Date Speed Coord NOAA Area Length FlareFlare

3. Magnetic Complex (1- X, 8 - M & 1 – C flare)3. Magnetic Complex (1- X, 8 - M & 1 – C flare)

Typical features: Typical features:

• a large sunspot w/ many small a large sunspot w/ many small satellites satellites

• twisted magnetic field & strong twisted magnetic field & strong magnetic shearmagnetic shear

• well pronounced moat structure well pronounced moat structure

In this magnetic topology, a CME, In this magnetic topology, a CME, too, can be a result of too, can be a result of reconnection between many reconnection between many closed twisted magnetic loops as closed twisted magnetic loops as suggested by the Quadruple suggested by the Quadruple Reconnection Configuration.Reconnection Configuration.

(Yurchyshyn et al., 2000, ApJ 540, 1143)

The magnetic complexes are The magnetic complexes are extended magnetic regions extended magnetic regions which consist of two adjacent which consist of two adjacent decaying active regions or a decaying active regions or a new magnetic region emerging new magnetic region emerging inside a decaying active inside a decaying active region. region.

Because of the age of these Because of the age of these active regions, a large scale active regions, a large scale helical magnetic fields (flux helical magnetic fields (flux tube) could be formed and tube) could be formed and CMEs could be associated with CMEs could be associated with their eruptions.their eruptions.

Another possibility is that a Another possibility is that a CME is a result of interaction CME is a result of interaction between the two adjacent between the two adjacent active regions.active regions.

AR 8375 on Nov 5, 1998AR 8375 on Nov 5, 1998

Typical features: Typical features:

• two opposite polarity two opposite polarity sunspots located in the same sunspots located in the same penumbra penumbra

• large magnitude of the large magnitude of the magnetic field and high magnetic field and high horizontal gradients horizontal gradients

• highly twisted magnetic highly twisted magnetic fields, strong magnetic shearfields, strong magnetic shear

Delta-sunspots are proposed to Delta-sunspots are proposed to be formed via emergence of a be formed via emergence of a twisted loop (Fan et al. 1999) twisted loop (Fan et al. 1999) and they are believed to be and they are believed to be connected above the connected above the photosphere.photosphere.

However, Zirin & Liggett However, Zirin & Liggett (1987), Shi & Wang (1993) and (1987), Shi & Wang (1993) and Liu & Zhang (1999) suggested Liu & Zhang (1999) suggested that delta-sunspots can be that delta-sunspots can be formed due to i) emergence of formed due to i) emergence of a cluster of sunspots; ii) a cluster of sunspots; ii) emergence of a satellite emergence of a satellite sunspot and iii) collision of two sunspot and iii) collision of two bipolar magnetic features and bipolar magnetic features and direct magnetic connections direct magnetic connections (“post flare” loops) within a (“post flare” loops) within a delta-sunspot occur only as it delta-sunspot occur only as it decays (Zirin & Liggett 1987).decays (Zirin & Liggett 1987).

Thus, a delta sunspot can be associated Thus, a delta sunspot can be associated with two independent magnetic fluxes with two independent magnetic fluxes which can reconnect and produce a CME which can reconnect and produce a CME as described in the Sweet (1958) and as described in the Sweet (1958) and Hirose (2001) models. Those models are Hirose (2001) models. Those models are based on the Quadruple Reconnection based on the Quadruple Reconnection Configuration Configuration (see also poster SH51C-03)

NOAA AR NOAA AR 94159415

ARs 39ARs 39

Filaments 6 Filaments 6

No Source 70No Source 70

Total 115 Total 115 CMEsCMEs

Yurchyshyn et al. 2004, ApJ, 619, 599

Yurchyshyn et al. 2004, Space Weather, 2, S02001

Yurchyshyn et al. 2004, Space Weather, 2, S02001