CAS Key Laboratory of Geospace Environment, USTC

The Deflection of 2008 September 13 CME in Heliosphere Space

ISEST, Hvar, Croatia,2013 June 17

Collaborators: Boyi Wang, Yuming Wang, Fang Shen, Pinzhong Ye ， Shui Wang

CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science &

Technology of China, Hefei, Anhui 230026, China

Chenglong Shen

1. Introduction

Make the limb(back) or high latitude CME hit Earth ➨ miss alert ➨ A possible reason for "problematic" ICMEs

Make the Earth direct CME miss Earth

➨wrong alert

Deflection of CMEs may significant influence their geoeffectiveness!

Deflection in meridian plane1. DIrect observed from coronagraph ➨ from high latitude region to equator

2. Widely reported and studied[e.g. MacQueen et al,1986, Gopalswamy et al., 2003, Cremades and Bothmer, 2004, Kilpua et al., 2009; Shen et al., 2011, Gui et al., 2011;Wang et al., 2011]

Wang et al., 2011

Deflection in ecliptic plane

1. Can not be direct observed before STEREO, but suggested by Wang et al., [2004]

2. Reported by some authors after STEREO[e. g. Gopalswamy et al., 2009;Gui et al., 2011; Poomvised et al., 2012; Temmer et al., 2012; Liu et al., 2012]

Deflection caused by CME interaction1. Could be direct observed by coronagraph[Gopalswamy et al., 2001]

2. Reported by recent work using STEREO observation[e. g. Shen et al., 2012, Lugaz et al., 2012]

➣ Magnetic Field Frozen-In, MFFI[Wang et al., 2004, Wang et al., 2006]

Source: Background solar windProperties:Fast CME -------> Deflect to EastSlow CME ------> Deflect to WestApplication:➨East-West asymmetry of the source of Earth arrival CME[Wang et al., 2004]

➨Geoeffectiveness of 2005 September CMEs[Wang et al., 2006]

Wang et al., 2004

Different explanation and models about the deflection

➣ Coronal Hole Model[Cremades and Bothmer, 2004 ;Gopalswamy et al., 2009]

Source: ➨Coronal holeProperties:Coronal holes push the CME awayApplication:➨`driverless’ shock in in-situ observations[Gopalswamy et al., 2009]

Gopaslwamy et al., 2009

➣ Magnetic energy density gradient model[e.g. Shen et al., 2011,Gui et al., 2011]

Source: ➨Background magnetic fieldProperties:➨CME deflect to lower magnetic energy density regionObservation results:➨CME would propagated along the current sheet➨Mainly happened <5RsShen et al., 2011

Gui et al., 2011

2.Coronagraph Observations

A halo CME in STB A east limb CME in STA

It is possible that this CME propagated east to the Sun-Earth line and direct to STB!

GCS model[Thernisien et al. 2006, Thernisien, 2009] fitting

From GCS model: ➨ Very slow CME

➨ Direct to STB at beginning➨ Continuously deflect to West from 05:00UT Sep 13 (>10Rs)

3.In-situ observations

From in-situ observations:➨ A ICME arrived Earth No full halo CME from September 9 to September 14---->"problematic" ICMEs?

➨ A ICME flank possible swept STB

JMAP from STEREO A

4. Propagation in heliosphere

JMAP from STEREO B

Method Arrival Time:

Direct Triangulation[Liu et al. 2009]

September 1700:02UT

HM Triangulation[Lugaz et al., 2009]

September 1618:05UT

ObservationsSeptember 1704:00UT

From interplanetary observations:

➨This CME did deflect to west during its propagation in heliosphere and make this east limb CME (seen from SOHO) arrived the Earth

5. Conclusion and discussionA full store of a CME’s deflect in heliosphere from Sun to 1AU is reported.

Why deflection happened?

➨ Solar wind

➨ Background magnetic field happened in the region >5 Rs -----> not for this event ➨ Coronal Hole

no obvious coronal hole -----> not for this event

Thanks!

A website of the full halo CMEs ( now from 2007 March 1 to 2012 May 31, will be updated continuously).

http://space.ustc.edu.cn/dreams/fhcmes/