An analysis of the 23 rd Solar Cycle’s High Speed Solar Wind Streams activity: sources of radiation hazards in Geospace Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 National and Kapodistrian University of Athens Physics Department Nuclear and Particle Physics Section Xystouris G. Sigala E. Prof. Mavromichalaki H. Xystouris G. Sigala E. Prof. Mavromichalaki H.

2  High Speed Solar Wind Streams (HSSWSs) and their nature └ What is an HSSWS? └ Potential Hazards for the Earth  HSSWSs in 23 rd Solar Cycle └ Categories of HSSWSs └ The table of HSSWSs in the 23 rd Solar Cycle └ Distributions regarding their parameters └ Conclusions Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 Presentation Outline

3  Intriligator, 1977: a rapidly increase of solar wind speed and a peak velocity equal or greater than 450km/s.  Bame, 1976 and Gosling, 1976: an observed variation of solar wind speed having an increment of at least 150 km/s within a 5–day interval.  Broussard, 1977: a period in which the solar wind speed is equal or greater than 500 km/s, averaged over a day.  Lindblad, 1981: a period in which the velocity difference between the smallest 3–hr velocity value and the largest 3–hr value of the following day is equal or greater than 100 km/s and it lasts for at least two days.  Mavromichalaki et al, 1988; 1998: The difference between the maximum velocity and the mean plasma velocity between the speeds immediately preceding and following the stream is equal or greater than 100 km/s, in a period lasting for at least two days. What is an HSSWS? Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 HSSWSs and their nature

4 The difference (ΔV) between the maximum velocity (V max ) and the mean plasma velocity of the speed immediately preceding and following the stream (V 0 ) is equal or greater than 100 km/s, in a period lasting for at least two days. Why?  It is more adequate for the purpose of solar-terrestrial studies  It is in agreement with our previous studies ΔV= V max - V 0 ≥ 100km/s & Δt ≥ 2 days Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 The definition of an HSSWS in this work: (Lindblad and Lundstedt, 1981; Mavromichalaki et al. 1988, 1999)

5 Typical Example of a HSSWS: Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 ΔV≥100km/s Δt≥2 days

6 Corotating Streams Sources of HSSWSs Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 Produced by the Coronal Holes (CH), in Quiet Areas N ~ 1/V |B| ~ V T ~ V

7 Flare Generated Streams Produced by Flares activity (FG), in Active Areas * * Also, generated by CMEs V, |B|, N, T: simultaneous increase with large variations T, N: independent of V SOHO – May 2, 1998 EIT 195Å, X1 Flare Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012

8 The HSSWSs contain very energetic particles, which are the source of the solar radiation. Hazards are encounter in two areas: Geospace └ Hazard for satellites (technological instruments) and astronauts Earth’s atmosphere and ground └ Maximum danger for aircrafts’ passengers └ Possible hazards for human health on the ground (many indications from several studies) due to the radiation interaction with Earth, inside and outside its atmosphere. Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 Potential Hazards for Earth

9 HSSWSs in the 23 rd Solar Cycle (May 1996 – December 2008) Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 Based on structure: ●Simple HSSWS ●HSSWS with Multiple Peaks ●HSSWS with Data Gaps  Interrupted HSSWS (duration less than 2 days) └ Interruption in Ascending Phase └ Interruption in Ascending Phase └ Interruption in Descending Phase └ Interruption in Descending Phase Based on the existence of another HSSWS: → Cases of Consecutive HSSWSs Categories of HSSWSs

10 a) Simple HSSWS b) HSSWS with Multiple Peaks c) HSSWS with Data Gaps d) Interrupted HSSWS e) Case of Consecutive HSSWSs Schematically each category (example of CH) (example of FG) Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012

11 Phases of 23 rd Solar Cycle Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 Sunspot Number Source: OMNIWeb database ( Ascending Phase May 1996 – Apr Maximum May 1999 – Dec Descending Phase Jan – Dec Minimum Jan – Dec General remarks for the 23 rd Solar Cycle: Very energetic Solar Cycle Very energetic Solar Cycle Extended Solar Activity in the Descending Phase Extended Solar Activity in the Descending Phase Secondary Maximum Secondary Maximum Extended Minimum Extended Minimum Extreme Solar Events July 14, 2000 April 15-18, 2001 October 28-29, 2003 November 4 & 20, 2003 January 20, 2005 December 13, 2006…

12 Table of the 23 rd Solar Cycles’ HSSWSs: Sources: OMNIWeb database ( National Space Science Data Center database ( National Oceanic and Atmospheric Administration (ftp://ftp.ngdc.noaa.gov/STP/SOLAR_DATA/SOLAR_FLARES/FLARES_XRAY/) Maris O., Maris G., 2005; Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 Nodd/mm/yyyy HH:mm Bartel Rotation No Day IMF PolarityDate of maximumV 0 [km/s]V max [km/s]Duration [days]CategorySource 112/5/ : / -13/5/ : SCH 215/5/ : / +15/5/ : SCH 318/5/ : / -20/5/ : SCH 424/5/ : / - / +25/5/ : S? 528/5/ : / -30/5/ : S? 65/6/ : /6/ : SCH 715/6/ : /6/ : SCH 818/6/ : /6/ : SCH 92/7/ : /7/ : SCH 1011/7/ : / -13/7/ : DF 1121/7/ : /7/ : DCH 1228/7/ : /8/ : MCH *1314/8/ : /8/ : SCH 1416/8/ : /8/ : SCH 1528/8/ : /8/ : MCH 164/9/ : /9/ : S?

13 Total HSSWS Simple Multiple Peaks Data Gap MP & DGConsec. Ratio Consec. / Total Asc. Phase Max Desc. Phase Min Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 General data of HSSWSs during the phases of 23rd Solar Cycle:

14 Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 Total Number of HSSWSs throughout the 23 rd Solar Cycle:  Peak flux of HSSWSs in 2003 (Descending Phase of the 23 rd Solar Cycle).

15 Duration of HSSWSs throughout the 23 rd Solar Cycle: Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 Solar CycleDuration 21 st 6-7 days 22 nd 4-5 days 23 rd 3-5 days Mavromichalaki H., Vassilaki A., 1998

16 Maximum Speed of HSSWSs throughout the 23 rd Solar Cycle: Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012  The mean speed of the HSSWSs increases during the Solar Cycle.

17 Sources of HSSWSs throughout the 23 rd Solar Cycle: Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012  Many CH HSSWSs, throughout the Cycle.

18 Conclusions Space Weather Effects on Humans: in Space and on Earth Space Research Institute, Moscow, Russia June 4-8, 2012 A number of 710 HSSWSs in Solar Cycle 23 (434 CH, 261 FG/CME, 15 unidentified sources) A number of 710 HSSWSs in Solar Cycle 23 (434 CH, 261 FG/CME, 15 unidentified sources) The FG HSSWSs follow the expected distribution in the 23rd Solar Cycle (with the exception of 1999). However the number of CH HSSWSs is high throughout the Solar Cycle, especially in its Descending Phase. The FG HSSWSs follow the expected distribution in the 23rd Solar Cycle (with the exception of 1999). However the number of CH HSSWSs is high throughout the Solar Cycle, especially in its Descending Phase. Peak flux of HSSWSs in 2003 (73 HSSWSs), in the Descending Phase of the 23 rd Solar Cycle. Peak flux of HSSWSs in 2003 (73 HSSWSs), in the Descending Phase of the 23 rd Solar Cycle. The greatest ratio of Consecutive HSSWSs appears in the Maximum of the 23 rd Solar Cycle (151 out of 214 – 71%) followed closely by the ratio of the Descending Phase (162 out of 239 – 68%). The greatest ratio of Consecutive HSSWSs appears in the Maximum of the 23 rd Solar Cycle (151 out of 214 – 71%) followed closely by the ratio of the Descending Phase (162 out of 239 – 68%). Average Duration of HSSWSs for the 23 rd Solar Cycle: 3-5 days Average Duration of HSSWSs for the 23 rd Solar Cycle: 3-5 days └ Duration in Maximum: 4-6 days └ Duration in Maximum: 4-6 days └ Duration in Descending Phase: 2-4 days └ Duration in Descending Phase: 2-4 days Maximum Speed is increasing during the 23 rd Solar Cycle, even beyond Maximum Maximum Speed is increasing during the 23 rd Solar Cycle, even beyond Maximum └ V max in Ascending Phase: km/s └ V max in Ascending Phase: km/s └ V max in Maximum: km/s └ V max in Maximum: km/s └ V max in Descending Phase: km/s → (Cycle’s largest speed: 1189 km/s) └ V max in Descending Phase: km/s → (Cycle’s largest speed: 1189 km/s) └ V max in Minimum: km/s └ V max in Minimum: km/s

19 Thank you Cпасибо ISS Expedition 30