The properties of CMEs embedded in extreme solar wind C. Cid, J. Palacios, A. Guerrero, E. Saiz and Y. Cerrato Space Weather Research Group University of Alcalá

What does ‘extreme space weather’ mean? Scale Physical measure R5 X20 flare (GOES Xray Flux=2x10-3 Watts m-2) S5 Flux level of 10 MeV protons = 105 particles cm-2s-1 sr-1 G5 Kp=9 Scale Physical measure G5 LDiñ > -300 nT C5 LCiñ > 35 nT min-1 Extreme geomagnetic storms X-flares

What is the trigger of a extreme geomagnetic storm (G5)? Extreme solar activity (X flares or even fast CMEs) NOT ALWAYS produces extreme geomagnetic storm But extreme geomagnetic storms ALWAYS happen after extreme solar wind conditions reaching the Earth What do ‘extreme solar wind conditions’ mean? ?

The number of data in the hystogram is not the same for all parameters!

In probability theory, statistics and econometrics, the Burr Type XII distribution or simply the Burr distribution[1] is a continuous probability distribution for a non-negative random variable. It is also known as the Singh–Maddala distribution[2]and is one of a number of different distributions sometimes called the "generalized log-logistic distribution". It is most commonly used to model household income  Household income is a measure of the combined incomes of all people sharing a particular household or place of residence. It includes every form of income, e.g., salaries and wages, retirement income, near cash government transfers like food stamps, and investment gains. Note when c = 1, the Burr distribution becomes the Pareto Type II (Lomax) distribution. When k = 1, the Burr distribution is a special case of the Champernowne distribution, often referred to as the Fisk distribution. 45 nT

All extreme solar wind events (B > 45nT) observed during ACE mission Year Month Day DoY 2000 July 15 197-198 2001 March 31 90 November 6 310 24 328 2002 May 23 143 2003 October 29 302 20 324 2004 7 312-313 2005 135 August 236

Is B enough to define XXXL solar wind? All events with Kp=9 or Dst<-300 nT are included in the list, that is, all G5 are included Good point! Almost no data gap in IMF at L1! Then, next questions to improve forecasting time: which are the drivers of B>45 nT? Is there any common signature in the solar triggers of extreme solar wind?

The interplanetary drivers Year Month Day Trigger References 2000 Jul 15 Isolated MC? [1], [2], [5] 2001 Mar 31 Multi-MCs [1], [2], [3], [4], [5] Nov 6 Multi-MCs+HSS [2], [3], [4], [5] 24 Multi-MC 2002 May 23 SH (M)+HSS [1], [2] 2003 Oct 29 Isolated MC [1] 20 2004 7 2005 [1], [5] Aug [1] Zhang et al. (2007), [2] Xie et al. (2006), [3] Cid et al. (2008), [4] Wang et al. [2003], [5]Cerrato et al. (2011)

The interplanetary drivers Year Month Day Trigger References 2000 Jul 15 Isolated MC? [1], [2], [5] 2001 Mar 31 Multi-MCs [1], [2], [3], [4], [5] Nov 6 Multi-MCs+HSS [2], [3], [4], [5] 24 Multi-MC 2002 May 23 SH (M)+HSS [1], [2] 2003 Oct 29 Isolated MC [1] 20 2004 7 2005 [1], [5] Aug [1] Zhang et al. (2007), [2] Xie et al. (2006), [3] Cid et al. (2008), [4] Wang et al. [2003], [5]Cerrato et al. (2011)

In-depth analysis of specific events does not conclude the same Dasso et al., JGR (2009)

Magnetic field vs. compositional anomalies He2+/H+  0.06 ICMEs (Richardson & Cane, 2004) <QFe> higher than 10: ICMEs (Lepri & Zurbuchen, 2004) O7+/O6+ ratio: Low for streams from CHs (Zurbuchen et al. 2002) High for ICMEs (Lepri et al. 2001; Henke et al. 2001) ln(Tp/Np-1)  proton specific entropy -consequences for the fitting High O7+/O6+ interval is more than three times that of the MC Cid et al., ApJ (2016)

Let’s double check the three remaining isolated MC triggers based on compositional anomalies

Conclusions Solar wind PDFs since the beginning of the ACE mission have been analyzed Extreme solar wind has been defined from the outlayers of the B magnitude All extreme geomagnetic storms were triggered by the solar wind defined as extreme Drivers of extreme solar wind are the result of the interaction among several solar ejections (probably at the interplanetary medium)

Thank you for your attention!