Radio Observations of Solar Eruptions

N. GopalswamyN. Gopalswamy Kiyosato Oct 26-29, 2004Kiyosato Oct 26-29, 2004

Radio Observations of Radio Observations of Solar Eruptions Solar Eruptions

N. GopalswamyN. Gopalswamy

NASA/GSFC Greenbelt MD USANASA/GSFC Greenbelt MD USA

Solar Physics with the Nobeyama RadioheliographSolar Physics with the Nobeyama Radioheliograph

Nobeyama Symposium Kiyosato Oct 26-29 2004Nobeyama Symposium Kiyosato Oct 26-29 2004

N. GopalswamyN. Gopalswamy Kiyosato, Oct 26-29 2004Kiyosato, Oct 26-29 2004

Thanks to …Thanks to …

• Y. Hanaoka• M. Shimojo• K. Shibasaki

• H. Nakajima• T. Kosugi• S. Enome• Nobeyama staff who pleasantly provided all necessary

support


Sun in MicrowavesSun in Microwaves• Quiet Solar disk at 10,000 K (most pixels

are at this temperature): QS• Small bright areas on the disk: active

regions (AR), post-eruption arcades (AF)• Dark areas on the disk: Filaments (F)

because Tb ~ 8000K• Bright regions outside the disk:

Prominences (P) Tb ~8000 K>> optically thin corona (~200 K); Sometimes mounds consisting of AR loops (Tb > 10000K)

• Dimming (deficit of free-free emission) can be observed in some limb events.

• Prominences and filaments erupt as part of coronal mass ejections

• 100s of eruptions documented on the NoRH web site

• Selected references: Hanaoka et al., 1994; Gopalswamy et al., 1996; 1999; 2003; Hori et al. 2000; 2002; Kundu et al. 2004

P

F

FAR

AF

QS

τff = 0.2∫f--2T-3/2n2dl >1 for n=1011 cm-3

T=8000 K, f=17 GHz and L >1 km Tb = T


EruptionsEruptions• Prominence/filament eruptions• (Jets) Kundu, Shimojo• (Blobs) Hori, Shibasaki• (Waves) White, Aurass• (Radio bursts) G. Huang• Slow Eruptions• Fast eruptions• CME-PE statistics• Implications to polarity reversal & GCR

modulation


Prominence EruptionProminence Eruption

1992 Jul 31 Hanaoka et al.1994

- Post-eruption arcade in microwaves- Prominence, Post-eruption Arcade Consistent with Standard Eruption model(Carmichael (1964), Sturrock (1968), Hirayama (1974),Kopp and Pneuman(1976) – CSHKP)- No CME observations, but SXR Dimming Signature

CME

P

SXT/AF


Three-Part CMEThree-Part CMEGopalswamy et al, 1996, 1997

Jul 10-11, 93

P

AF

16 km/s

12 km/s

4 km/s

- All features of a typical CME in X-rays and Microwaves- Kinetic energy (5.1026 ) < thermal energy (6.1028)- Low-end CME- Helical motion of the prominence followed by radial eruptionRecent examples of helical motion by Hori (2000)


Filament Eruption and DimmingFilament Eruption and DimmingGopalswamy and Hanaoka, 1998

Final: 68 km/sAccel: 11ms-2

06:4101:20

AF


Filament is CME COREFilament is CME CORE

He10830 filament at17:54 UT slowly rises and reaches the limb by 00:03 UT (2/7) tracked in microwaves as a prominence becomes the CME core in white light

Gopalswamy et al .98 GRL

Direct comparison with CMEs became possible when SOHO data started pouring in

Additional Core

Gopalswamy, 1999MLSO He 10830 images


Post-eruption ArcadePost-eruption ArcadeYohkoh/SXT images showing the formation of a post-eruption arcade, which lasts for a day

SXR Arcade after eruptionlarger volume involved than

Indicated by filament1-AU Magnetic Cloud


A Complex Filament EruptionA Complex Filament EruptionLWS CDAW 2002 (Shimojo), Kundu et al. 2004 See also Hanaoka & Shinkawa, 1999 on covering of bright plage by erupted filament


Two CMEs?Two CMEs?Kundu et al. 2004

50km/s

650km/s

7.25 Ro/hrOnset 04:49Corrected:4:45


CME Collision: A slow CME is CME Collision: A slow CME is Deflected by a Fast oneDeflected by a Fast one

• Slow CME (290 km/s) overtaken by a fast CME (660 km/s)

• The slow CME core deflected to the left from its trajectory


Acceleration likely caused by the Acceleration likely caused by the impact of fast second CMEimpact of fast second CME


Microwave Observations of CME Microwave Observations of CME InitiationInitiation

A very fast CME: 5 Rs in less than 30 min > 2000 km/s


An Eruption viewed in microwavesAn Eruption viewed in microwaves

Gopalswamy, Shimojo, Shibasaki, 2004


Microwave Emission seems to be Microwave Emission seems to be from the body of the CME from the body of the CME

02:17 – 02:16 02:17 – 02:13

C202:30

17 GHz17 GHz

C302:42

C2

1635 km/s


An Eruption viewed in microwavesAn Eruption viewed in microwaves

02:15 UT

HXR 930 km/sHudson et al. 2001

Nobeyama HXTCatalog


Microwave Source EvolutionMicrowave Source Evolution

HXR

Hudson et al 2001


Similar to Moving type IV?Similar to Moving type IV?

17 GHz1925 km/s

C2

C3

- The Microwave Structure is either the CME itself or a substructure, but not the core.- Microwave spectrum (17 and 34 GHz) indicates nonthermal emission- Similar to moving type IV burst

2465 km/s

1635 km/s

Gopalswamy & Kundu 1992

73.8 MHz

1600 km/s


CMEs & Prominence Eruptions (PEs) : CMEs & Prominence Eruptions (PEs) : Statistical StudiesStatistical Studies

• Most studies started with CMEs and found PEs to be the most common near-surface activity (Webb et al., 1976; Munro et al. 1979)

• Reverse studies were rare. Hori et al. studied 50 NoRH PEs (2/1999-5/2000) and found a 92% association. (They required simultaneous availability of SOHO, Nobeyama and Yohkoh data)

• A comprehensive study using all the PEs (226) detected automatically showed that 72% of all PEs were associated with CMEs (Gopalswamy et al. 2003a; 2004)


Height-Time Plots of Height-Time Plots of All PEsAll PEs

• The height-time plots can be broadly classified as radial (R – 82%) and Transverse (T – 18%)

• R events reached larger height (1.4Rs) compared to T events (1.19Rs)

• Most R events (83%) were associated with CMEs; most T events (77%) were not.

• 134/186 (72%) PEs had CMEs; 42 (22%) had no CMEs; 11 (6%) had streamer changes

• The majority of Streamer change events were T events; the rest were low-height R events

Gopalswamy et al. 2003


Properties of Prominence Eruptions Properties of Prominence Eruptions (PEs) with and without CMEs:(PEs) with and without CMEs:

non-CME PEs are slower, have mostly transverse trajectories, non-CME PEs are slower, have mostly transverse trajectories, and the maximum height reached is rather smalland the maximum height reached is rather small

1.20 Ro

1.40 Ro

22 km/s

68 km/s

Without

CMEs

Without

CMEs

With

CMEs

With

CMEs


2001/08/29 Event: 2001/08/29 Event: no CMEno CME

LASCO

LASCO/C2 images show no changes around the

Time of Prominence Eruption

17 GHz Nobeyama


Streamer ChangeStreamer Change

Most of these streamers Disrupted within a day.


Temporal Relationship of PEs and CMEsTemporal Relationship of PEs and CMEs

• The onset time differences close to zero.

• CME onset times extrapolated to 1 Rs from extrapolating linear h-t plots


PE-CME Spatial PE-CME Spatial RelationshipRelationship

• Strong evidence for PE-CME association

• Previously shown by Hundhausen (1993) for SMM CMEs

Open circles PEs during SOHO downtimes

PE

CME

During Solar Minimathe global dipolar fieldis strong and guides eruptions


Non-radial motionNon-radial motion

Prominence Eruption in the SE directionCorresponding changes in the streamerCME & Core position angle ~ 90 degInfluence of the global fieldGopalswamy, Hanaoka, Hudson 1999Filippov, Gopalswamy, Lozhechkin, 2001


CMEs & ProminencesCMEs & Prominences• High latitude (HL) prominence eruptions and

CMEs during CR 1950-1990 (mid ’99 – early ’02)

• N-S asymmetry (NHL ends in 11/00; SHL ends in 5/02)

• These CMEs are not associated with sunspot activity

Gelfreikh et al 2002


WE

N

S

+++++

- - - -

+ + + +

- - - -

+ + + + +

- - - -

PCF


Cycle 23Cycle 23• HL Rate picks up when polar B

declines• North polar reversal at the time

of cessation of NHL CMEs• South polar reversal 1.5 yr later,

again coinciding with the cessation of SHL CMEs

• LL CME rate rather flat after a step-like increase

• Consistent with the time of PCF disappearance

Arrows: Lorenc et al. 2003; Harvey & Recely, 2003; Gopalswamy et al., 2003


Cycle 21Cycle 21• Solwind coronagraph on

board P78-1 (corrected rates published by Cliver et al., 1994)

• PCF: Webb et al. 1984; Lorenc et al. 2003

• KPNO mag data• CME cessation coincides

with the polarity reversal


CMEs and GCR ModulationCMEs and GCR Modulation

Moraal, 1993

A>0A<0

HL

LL Lara et al. 2004

Gopalswamy 2004

A>0

Gopalswamy 2004

NoRH PE


Concluding RemarksConcluding Remarks

• NoRH has contributed profoundly to the study of CMEs by providing info on various aspects: CME initiation/acceleration, Post-eruption arcade, CME relation to global B

• Clarified CME-PE relationship unambiguously• Contributed to the understanding of Polarity reversal and high-

latitude Eruptions• Prom eruptions have implications to Sun-Earth connection as well

as Sun-GCR connection• It will be great if NoRH can see a 22-yr cosmic ray modulation cycle


Polarity Reversal in Polarity Reversal in Photospheric FieldPhotospheric Field


When are the reversals?When are the reversals?

• HL streamer peak (Feb 2000) implies presence of HL closed structures. reversal is not complete

• HL streamer brightness declines significantly towards the end of 2000 – agrees with CME cessation

Wang, Sheeley & Andrews, 2002


A High-latitude CME & PCFA High-latitude CME & PCF

Nobeyama Radio ProminenceLASCO/C2


Emission MechanismsEmission Mechanisms(n, T, B, F(n, T, B, Fntnt))

• Thermal Emission- Free-free (8000 K to 10 MK)- Gyroresonance (Active Regions)• Nonthermal - Gyrosynchrotron (incoherent)- Plasma emission (nonthermal electrons

plasma waves radio emission at fp, 2fp)• Other coherent processes

Documents

Radio Observations of Solar Eruptions