1. Analysis of 3 and 8 April 2010 Coronal Mass Ejections and their Influence on the Earth Magnetic Field Marilena Mierla and SECCHI teams at ROB, USO and MPS, GEO team at IGAR Royal Observatory of Belgium Institute of Geodynamics of the Romanian Academy Research Centre for Atomic Physics and Astrophysics, University of Bucharest

2. Motivation of the work Instruments and Data Description Data Analysis Summary Contents

3. Motivation of the work It is important to know their source region, their mechanisms of initiation, their true speed and direction of propagation in order to accurately predict their arrival time to the Earth. Definition CMEs are ejections of parts of the magnetized solar atmosphere that occur over the course of hours to days. Do they influence us? - Yes When directed towards the Earth they can create major disturbances in the magnetosphere.

4. Instruments: LASCO-C2/SOHO LASCO-C2 is a white light coronagraph which observes solar corona from 2 to 6 solar radii. http://sohowww.nascom.nasa.gov/ NASA mission launched on December 2, 1996.

5. Instruments: SECCHI/STEREO SECCHI: EUV image (EUVI); 2 white-light coronagraphs (COR1 and COR2) 2 white light heliospheric imagers: HI1 and HI2 http://stereo-ssc.nascom.nasa.gov/ NASA mission launched on October 25, 2006.

6. Instruments: SECCHI

8. PROBA2 http://proba2.sidc.be/index.html/ PROBA2 is an ESA micro-satellite launched on November 2, 2009. PROBA2 follows a sun- synchronous orbit.

9. Instruments: SWAP and LYRA on PROBA2

10. Advanced Composition Explorer (ACE) http://www.srl.caltech.edu/ACE/ace_mission.html The four ACE instruments and the data they supply: EPAM - Energetic Ions and Electrons MAG - Magnetic Field Vectors SIS - High Energy Particle Fluxes SWEPAM - Solar Wind Ions NASA mission launched on August 25, 1997. Geomagnetic data from various Earth stations: http://ngdc.noaa.gov/geomag/

11. 3 April 2010 CME - COR1 COR1-A 09:50 UT COR1-B 09:50 UT FOV: 1.4 – 4 solar radii

12. 3 April 2010 CME - COR2 COR2-B 11:54 UTCOR2-A 11:54 UT FOV: 2.5 – 15 solar radii

13. 3 April 2010 CME - LASCO-C2 10:55 UT 12:06 UT FOV: 2 – 6 solar radii

14. 3 April 2010 CME – HI1 EUVI-A 15:29 UT EUVI-B 15:29 UT FOV: 15 – 84 solar radii

15. 3 April 2010 CME – HI1 EUVI-A 18:49 UT EUVI-B 18:49 UT

16. 5 April 2010 CME – HI2 EUVI-A 00:09 UT EUVI-B 00:09 UT FOV: 66 – 318 solar radii

17. In-situ signatures – 5 April 2010 CME starts on 5 April and finishes early on the 7. Long duration is due to the encounter of the ICME with a high-speed stream. Shock arrival at ACE: ~ 8:00 UT

18. Arrival to the Earth – 5 April 2010 - geomagnetic storm: Kp=6

19. AR: 11059 Location: S23W17 Hale: β http://solarmonitor.org/full_disk.php?date=20100403&type=smdi_maglc&indexnum=1

20. 3 April 2010 CME – SWAP 08:40 UT 09:15 UT

21. 3 April 2010 CME – SWAP (Dimming + EIT wave)‏ 09:03 UT 09:15 UT

22. 3 April 2010 CME – EUVI 304 EUVI-A 08:56 UT EUVI-B 08:56 UT

23. 3 April 2010 CME – EUVI 304 (Prominence eruption)‏ EUVI-A 09:46 UTEUVI-B 09:46 UT

24. 3 April 2010 CME – LYRA (Flare)‏

25. 3 April 2010 CME – Reconstruction: FM Longitude = 2 degrees Latitude = -27 degrees Height = 3.57 Rs

26. A B3.7 long duration flare occurred in AR 11060 at N25E16 (Earthview) starting on April 8, 02:30. It was associated with an erupting filament, a wave, and double dimmings. A bright CME to the northeast was observed in LASCO as well as the following halo. A shock was detected at SOHO and ACE on April 11, ~12:00 UT followed by an ICME and possible Magnetic Cloud, starting early on April 12. Southward field during and before this time resulted in a small geostorm with Kp reaching 6 early on Apr. 12. http://secchi.nrl.navy.mil/spwx/index.php?p=20100408event 8 April 2010 CME

27. Summary  Due to multispacecraft observations the two CMEs could be followed all the way from the Sun to the Earth  On-disk signatures show: EUV dimmings, EIT waves, post-eruptive arcades  The CMEs observed in white-light images are seen as limb in STEREO and partial halos in LASCO (Earth view)  They could be triangulated to get the true direction of propagation and the true speeds in coronagraph field of view  Both CMEs reach the Earth 2-3 days after their eruptions on the Sun. They produced geomagnetic storms when interacting with the Earth magnetic field

28. To study: - expansion speed of the EIT wave (SWAP, EIT) – comparison with the expansion speed of the CME (LASCO, COR) - mass calculation from dimming (SWAP + EIT (?)) - comparison with the mass of the CME (LASCO, COR) - follow the CME from the source region to the Earth: Jmaps - get the speed from reconstruction – compare it with the speed observed at the spacecraft → infer the interplanetary conditions - check - if the CME was deflected or followed a radial direction (at which distance from the sun center this happened?); - if it was accelerated/decelerated in its way to the Earth (which distance?)