Radio observations of solar eruptions
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Radio Observations of Solar Eruptions. N. Gopalswamy NASA/GSFC Greenbelt MD USA Solar Physics with the Nobeyama Radioheliograph Nobeyama Symposium Kiyosato Oct 26-29 2004. Thanks to …. Y. Hanaoka M. Shimojo K. Shibasaki H. Nakajima T. Kosugi S. Enome

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Radio Observations of Solar Eruptions

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Radio Observations of Solar Eruptions

N. Gopalswamy

NASA/GSFC Greenbelt MD USA

Solar Physics with the Nobeyama Radioheliograph

Nobeyama Symposium Kiyosato Oct 26-29 2004

Kiyosato Oct 26-29, 2004


Thanks to …

  • Y. Hanaoka

  • M. Shimojo

  • K. Shibasaki

  • H. Nakajima

  • T. Kosugi

  • S. Enome

  • Nobeyama staff who pleasantly provided all necessary support

Kiyosato, Oct 26-29 2004


Sun 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

AF

AR

F

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

Kiyosato, Oct 26-29 2004


Eruptions

  • 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

Kiyosato, Oct 26-29 2004


Prominence Eruption

1992 Jul 31 Hanaoka et al.1994

P

CME

SXT/AF

- 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

Kiyosato, Oct 26-29 2004


Three-Part CME

Gopalswamy et al, 1996, 1997

P

16 km/s

12 km/s

AF

4 km/s

Jul 10-11, 93

  • - 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 eruption

  • Recent examples of helical motion by Hori (2000)

Kiyosato, Oct 26-29 2004


Filament Eruption and Dimming

Gopalswamy and Hanaoka, 1998

Final: 68 km/s

Accel: 11ms-2

01:20

06:41

AF

Kiyosato, Oct 26-29 2004


Filament is CME CORE

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

MLSO He 10830 images

Gopalswamy, 1999

Additional 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

Kiyosato, Oct 26-29 2004

Gopalswamy et al .98 GRL


Post-eruption Arcade

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

SXR Arcade after eruption

larger volume involved than

Indicated by filament

1-AU Magnetic Cloud

Kiyosato, Oct 26-29 2004


A Complex Filament Eruption

LWS CDAW 2002 (Shimojo), Kundu et al. 2004

See also Hanaoka & Shinkawa, 1999 on covering of bright plage by erupted filament

Kiyosato, Oct 26-29 2004


Two CMEs?

Kundu et al. 2004

7.25 Ro/hr

Onset 04:49

Corrected:4:45

650km/s

50km/s

Kiyosato, Oct 26-29 2004


CME Collision: A slow CME is Deflected 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

Kiyosato, Oct 26-29 2004


Acceleration likely caused by the impact of fast second CME

Kiyosato, Oct 26-29 2004


Microwave Observations of CME Initiation

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

Kiyosato, Oct 26-29 2004


An Eruption viewed in microwaves

Gopalswamy, Shimojo, Shibasaki, 2004

Kiyosato, Oct 26-29 2004


Microwave Emission seems to be from the body of the CME

02:17 – 02:13

02:17 – 02:16

17 GHz

17 GHz

1635 km/s

C2

C3

02:42

C2

02:30

Kiyosato, Oct 26-29 2004


An Eruption viewed in microwaves

02:15 UT

HXR 930 km/s

Hudson et al. 2001

Nobeyama HXT

Catalog

Kiyosato, Oct 26-29 2004


Microwave Source Evolution

HXR

Hudson et al 2001

Kiyosato, Oct 26-29 2004


Similar to Moving type IV?

1600 km/s

2465 km/s

C2

17 GHz

1925 km/s

73.8 MHz

1635 km/s

Gopalswamy & Kundu 1992

- 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

C3

Kiyosato, Oct 26-29 2004


CMEs & Prominence Eruptions (PEs) : Statistical 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)

Kiyosato, Oct 26-29 2004


Height-Time Plots of All PEs

Gopalswamy et al. 2003

  • 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

Kiyosato, Oct 26-29 2004


Properties of Prominence Eruptions (PEs) with and without CMEs:non-CME PEs are slower, have mostly transverse trajectories, and the maximum height reached is rather small

1.20 Ro

Without

CMEs

22 km/s

Without

CMEs

With

CMEs

68 km/s

With

CMEs

1.40 Ro

Kiyosato, Oct 26-29 2004


17 GHz Nobeyama

2001/08/29 Event: no CME

LASCO

LASCO/C2 images show no changes around the

Time of Prominence Eruption

Kiyosato, Oct 26-29 2004


Streamer Change

Most of these streamers

Disrupted within a day.

Kiyosato, Oct 26-29 2004


Temporal 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

Kiyosato, Oct 26-29 2004


PE-CME Spatial Relationship

Open circles 

PEs during

SOHO downtimes

  • Strong evidence for PE-CME association

  • Previously shown by Hundhausen (1993) for SMM CMEs

During Solar Minima

the global dipolar field

is strong and guides

eruptions

PE

CME

Kiyosato, Oct 26-29 2004


Non-radial motion

  • Prominence Eruption in the SE direction

  • Corresponding changes in the streamer

  • CME & Core position angle ~ 90 deg

  • Influence of the global field

    Gopalswamy, Hanaoka, Hudson 1999

    Filippov, Gopalswamy, Lozhechkin, 2001

Kiyosato, Oct 26-29 2004


CMEs & 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

Kiyosato, Oct 26-29 2004


N

+++++

PCF

- - - -

+ + + +

E

W

- - - -

+ + + + +

- - - -

Kiyosato, Oct 26-29 2004

S


Cycle 23

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

  • 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

Kiyosato, Oct 26-29 2004


Cycle 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

Kiyosato, Oct 26-29 2004


CMEs and GCR Modulation

Gopalswamy 2004

Gopalswamy 2004

A<0

A>0

A>0

HL

NoRH PE

LL

Lara et al. 2004

Moraal, 1993

Kiyosato, Oct 26-29 2004


Concluding 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

Kiyosato, Oct 26-29 2004


Polarity Reversal in Photospheric Field

Kiyosato, Oct 26-29 2004


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

Kiyosato, Oct 26-29 2004


A High-latitude CME & PCF

Nobeyama Radio Prominence

LASCO/C2

Kiyosato, Oct 26-29 2004


Emission Mechanisms(n, T, B, Fnt)

  • 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

Kiyosato, Oct 26-29 2004


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