Laboratoire de Physique des Plasmas S OLAR E VENTS TOWARDS THE E ARTH IN 2002 B.Schmieder (1), N. Cornilleau-Wehrlin (1), K. Bocchialini (2), M. Menvielle (3), A. Chambodut(4), D. Fontaine(1),B. Grison (5),C. Lathuillère (6), A. Marchaudon(7), M. Pick(8), F. Pitout(7), S.Régnier(9), N. Vilmer (8), Y. Zouganelis(1) ESWW12 Ostende November 2015

Back and Forth method It is a classical method to follow a solar event towards the Earth and see its geoeffectiveness. Many case studies exist (i.e. Hanuise et al, 2006), some statistics have been performed selecting only halo CMEs (Gopalswamy et al, 2009, Cid et al, 2012) We propose a statistical analysis covering one year (2002) to investigate the link between SSC (Storm Sudden Commencement), detected by the magnetic observatories on the ground and the Coronal Mass ejection (CME). The method is back and forth to find the correct association of events ESWW12 Ostende November 2015

Starting point #1 SSC May at 10:18 UT By using the geomagnetic indices (Dst, SYM-H…) SSC Storm Sudden Commencement = compression of the magnetosphere indicating the arrival of the shock. Date; Amplitude; Quality ( :18; 78 nT; 2) Dst (hour) et SYM-H (1 mn) variations related to the annular magnetospheric currents of the horizontal magnetic component at the Earth surface Value of the minimum; Classification (-109; Intense Storm ) nT SSC day of the year 142 : 22 May ESWW12 Ostende November 2015

Starting point # 2 Sun: search of CME SOHO :13 UT AR 9948 EIT : 30.4 nm EIT : 19.5 nm Location (881,-319 arcsec) and characteristics of the source region (AR, Filament,Flare) LASCO/SOHO CME : speed, altitude, acceleration, time of exit of the field of view (150 4km/s, 28 Rs, -10.4, 06:50 UT ) ESWW12 Ostende November 2015

X ray Flux measured by GOES W/m 2 C Class ESWW12 Ostende November 2015

Radio bursts in the Solar Wind at L1 Type II: associated with a shock Type IV: associated by a CME, important ejection ESWW12 Ostende November 2015

Interplanetary Medium at L1 : ACE Satellite Characteristics of the observations: ICME (Interplanetary CME) or NOT ? t _ssc ICME : increase of V t1: shock t2 : start of the ICME t3 : end of the ICME ESWW12 Ostende November 2015

Ionospheric radars SuperDARN : Polar Cap potential through the pole SSC Maximum value of the PCP (85-95) Maximum time after the SSC (01:15) Nb of points (quality) ( ) ESWW12 Ostende November 2015 Global convection maps

Thermosphere : Measurements of the satellite CHAMP (400 km) The measurements are normalised by a quiet time model Coef. = 2 => augmentation de 100% of the density. Weak signal for Dst >-15 otherwise the density increases by a factor 1.5 to 2.5 (good agreement with the study of Krauss et al (2015) ESWW12 Ostende November 2015

Some results obtained in one year of measurements (2002) during the cycle 23 maximum From – 35 SSC identified in 2002 – 51 CME with an identified solar source (if no halo CME has been identified we search for a partial CME) – Characterisation of the perturbation recorded at L1 before the SSC – Geomagnetic indices – Ionosphere (Super Darn, Thermosphere CHAMP) – Only a few of in situ magnetosphere observations (Cluster operated until July 2002) ESWW12 Ostende November 2015

Some results Association YES/NOT with CME  SSC – propagation in a time window ~1 to 5 days (ballistic propagation ballistic between 300 km/s and 1500 km/s) – When there is an association, work on the model of propagation using a drag model. If you know the velocity at the starting point and the velocity at the arrival the drag coefficient Ss can be determined with more precision. – Using empiric models does not give better results ESWW12 Ostende November 2015

Comparison SSC at L1 Characteristics at L1 Nb Mean SSC amplitude > 35 nT Large Dst -200<.<-100 nT Intense storms Medium Dst -100<.< -50 nT Moderate storms Weak Dst > -50 nT Weak storms ICME 17 7**8**45 CIR-SIR * OTHER (SW) UNCLEAR ICME Total 31 *** * Co rotating interaction region (SIR visible in more than one rotation) ** Only two events with large amplitude (> 35 nT) correspond to large Dst (not link to the shock but to the compression) *** 31 for 35 SSC because 4 pairs of sscs ESWW12 Ostende November 2015

Characteristics of 35 SSC sources: 51 CME and solar source Type of SSC origin1 Solar source multi sources No solar souce Total CMEH66 CMEN55 2 CMEN,H ; 3 sources CIR -SIR55 No ID55 Total ESWW12 Ostende November 2015 With 4 false detections (ICME not detected in L1) 26 Halo CMEs only 16 impacted the Earth with SSCs. 25

Propagation speed CME at L1 After identification, drag coefficient for a drag model Coefficient (10-7 km-1) >1.5 Case Number Only 23 cases of ejections have been considered. No correlation with the speed May be some correlation with the mass ESWW12 Ostende November 2015

Conclusions and perspectives (1) From the Sun to the Earth Association CME – SSC: One year of data during the solar maximum; Relatively low number for a good statistic Results: variable 35 SSC 51 CME ESWW12 Ostende November 2015

25 from the 35 SSC associated with CME and identified solar source; 4 CIR; 5 unclear 11 SSC clear identified with one ICME 14 of the 25 SSC are due to multiple CMEs (can explain the « unclear » case at L1) L1 : 19 ICME identifiable 5 SSC with no identified solar source (no CME neither CIR) Speed model have to be upgraded ESWW12 Ostende November 2015 Conclusions and perspectives (2)

Conclusions and perspectives (3) The 2002 data are in a data base (1996_2007) at ias.u-psud.fr which should publish in a paper (in preparation) We need to increase the statistic base: – To complete the results in 2002 with results of other papers. – To use a data base – To complete with data of new satellites in operation since 2007 (STEREO..) Future study : SSC without CME Atelier Météo Meudon juin 2015 NCW

Laboratoire de Physique des Plasmas Thank for your attention Acknowledgment: PNST.

Vitesse de propagation CME vers L1 Après identification, calcul du coefficient de freinage dans le modèle avec freinage: Coefficient (10-7 km-1) >1.5 Nb cas10841 Le calcul n’a pu se faire que sur 23 cas Pas de corrélation trouvée avec la vitesse d’éjection  regarder la masse ESWW12 Ostende November 2015