Mike Lockwood STFC/Rutherford Appleton Laboratory & Southampton University

1. How the Sun Influences Modern Life Mike Lockwood STFC/Rutherford Appleton Laboratory & Southampton University Our life-giving star: the flow of energy from the Sun to the Earth BA Festival of Science, York, Monday 10th September 2007

2. How the Sun Influences Modern Life Galactic Cosmic Rays Solar Energetic Particles Satellite Damage Human Spaceflight Hazards Sun and Climate Change

3. How the Sun Influences Modern Life Galactic Cosmic Rays Solar Energetic Particles Satellite Damage Human Spaceflight Hazards Sun and Climate Change

4. The Solar Wind Plasma A Coronograph is a man-made eclipse with an occulting disc blocking out the visible surface of the Sun (the Photosphere). Allows us to observe the hot solar atmosphere, the Corona Continuous outflow of ionised gas (“plasma”), The Solar Wind,  1014 kg per day EventsCMEs eject ~1013 kg at about 350 km s-1 (PS watch the comet!)

5. The “Frozen-in flux” Theorem ( by definition of B ) Magnetic Field B Charged particle motions Lorentz Force B B

6. Emergence of Coronal Magnetic Flux Loops of magnetic flux emerge through the surface in active (sunspot) regions Some of this flux is “open” rises through the corona and is frozen-in to the solar wind outflow

7. Parker Spiral (an example of frozen-in) Solar wind flow is radial Solar rotation and radial solar wind generates a Parker spiral field structure Field is “frozen-in” to the solar wind flow Sun

8. Parker Spiral (an example of frozen-in) Solar wind flow is radial Solar rotation and radial solar wind generates a Parker spiral field structure Field is “frozen-in” to the solar wind flow Sun

9. Parker Spiral (an example of frozen-in) Solar wind flow is radial Solar rotation and radial solar wind generates a Parker spiral field structure Field is “frozen-in” to the solar wind flow Sun

10. Parker Spiral (an example of frozen-in) Solar wind flow is radial Solar rotation and radial solar wind generates a Parker spiral field structure Field is “frozen-in” to the solar wind flow Sun

11. Parker Spiral (an example of frozen-in) Solar wind flow is radial Solar rotation and radial solar wind generates a Parker spiral field structure Field is “frozen-in” to the solar wind flow Sun

12. Parker Spiral (an example of frozen-in) Solar wind flow is radial Solar rotation and radial solar wind generates a Parker spiral field structure Field is “frozen-in” to the solar wind flow Sun

13. Parker Spiral (an example of frozen-in) Solar wind flow is radial Solar rotation and radial solar wind generates a Parker spiral field structure Field is “frozen-in” to the solar wind flow Sun

14. Parker Spiral (an example of frozen-in) Solar wind flow is radial Solar rotation and radial solar wind generates a Parker spiral field structure Field is “frozen-in” to the solar wind flow Sun

15. Parker Spiral (an example of frozen-in) Solar wind flow is radial Solar rotation and radial solar wind generates a Parker spiral field structure Field is “frozen-in” to the solar wind flow Sun

16. Parker Spiral (an example of frozen-in) Solar wind flow is radial Solar rotation and radial solar wind generates a Parker spiral field structure Field is “frozen-in” to the solar wind flow Sun

17. Parker Spiral (an example of frozen-in) Solar wind flow is radial Solar rotation and radial solar wind generates a Parker spiral field structure Field is “frozen-in” to the solar wind flow Sun

18. Parker Spiral (an example of frozen-in)  Interplanetary scintillation is the “twinkling” if radio stars caused by irregularities in the solar wind  Tomographic reconstruction from interplanetary scintillations Solar rotation and radial solar wind generates a Parker spiral field structure Co-rotates with the solar corona (every 27 days in Earth’s frame)

19. interstellar wind A Stellar Heliosphere  Hubble observations of the heliosheath behind the bow shock where the heliosphere of LL Ori heliosphere meets its (dense) local interstellar wind in the Orion nebula heliosheath bow shock heliopause

20. Galactic Cosmic Rays The coronal source fluxis dragged out by the solar wind flow togive the heliospheric field which shields Earth from galactic cosmic rays

21. Cosmic Rays Anticorrelation with sunspot numbers Sunspot Number Huancauyo – Hawaii neutron monitor counts (>13GV) Climax neutron monitor counts (>3GV)

22. A Stellar Heliosphere Cosmic ray tracks in a bubble chamber

23. How the Sun Influences Modern Life Galactic Cosmic Rays Solar Energetic Particles Satellite Damage Human Spaceflight Hazards Sun and Climate Change

24. Solar Energetic Protons(SEPs)  Energised at the shock fronts of CMEs (and CIRs)  Follow heliospheric field lines  Seen here striking the imager CCD plate of the LASCO coronograph on the SoHO spacecraft

25. Parker Spiral (an example of frozen-in) Sun

26. Parker Spiral (an example of frozen-in) CME  SEPs generated at front of CMEs Guided along IMF Sun

27. How the Sun Influences Modern Life Galactic Cosmic Rays Solar Energetic Particles Satellite Damage Human Spaceflight Hazards Sun and Climate Change

28. spacecraft electronics box penetrating radiation sensitive component floating circuit trace can collect charge and discharge charge buried in insulator can discharge Spacecraft Damage radiation environment damage: Surface charging  0.1 – 100 keV electrons Single event upsets  MeV ions Cumulative radiation dose  Limits spacecraft lifetime Internal charging (“deep dielectric charging”)  MeV electrons

29. The Bastille Day Storm CMEs seen by IPS  Tomographic reconstruction from interplanetary scintillations

30. The Bastille Day Storm GCRs and SEPs Neutron Monitor counts ►Ground-level enhancement (GLE) of solar energetic particles seen between Forbush decreases of galactic cosmic rays caused by shielding by the two CMEs ►Here seen at stations in both poles (McMurdo and Thule) nm counts GLE Forbush decrease caused by 1st CME Forbush decrease caused by CME associated with GLE

31. The Bastille Day Storm SEPs seen at Geostationary Orbit ▲▼ = Single event upsets (SEUs) suffered by satellites in geostationary and high altitude orbits  several satellites were powered down to protect them

32. How the Sun Influences Modern Life Galactic Cosmic Rays Solar Energetic Particles Satellite Damage Human Spaceflight Hazards Sun and Climate Change

33. BIOLOGICAL EFFECTS Heavy ions breaks molecular links & can cause nuclear reactions so (e.g.) C converted to N and O in molecules

34. The Apollo Missions

35. Instantly fatal Severe radiation sickness Severe radiation sickness Raised cancer risk Raised cancer risk Above annual dose Above annual dose Instantly fatal Average annual dose at Earth’s surface Max. annual dose for a radiation worker SEPs: just how lucky were the lunar astronauts?  SEPs during the era of the Apollo Missions

36. Instantly fatal Severe radiation sickness Raised cancer risk Above annual dose SEPs: what’s the space weather been like?  SEPs and Galactic cosmic rays since the Apollo Missions

37. How the Sun Influences Modern Life Galactic Cosmic Rays Solar Energetic Particles Satellite Damage Human Spaceflight Hazards Sun and Climate Change

38. Total Solar Irradiance best composite of observations (by PMOD, Davos) shows 0.1% solar cycle variation damped out by large thermal capacity of Earth’s oceans but are there century- scale changes which would not be damped?

39. Total solar irradiance changes and magnetic field emergence  Dark sunspots and bright faculae are where magnetic field threads the solar surface

40. TSI reconstructions TSI (for 3 assumptions for the Maunder Minimum) A. [Fp]MM = [Fp]now B. [Fp]MM = 0 C. [Fp]MM = [Fp]now /2 Open Solar Flux, FS

41. running mean over T=[9:(1/4):13] yrs running mean over T=L yrs Recent trends - revealed by averaging over solar cycle length, L ►sunspot number, R ►solar cycle length, L ►FSfrom IMF data ►GCR counts C (Climax n.m.) ►PMOD composite of TSI data