The Maunder minimum: An extreme space climate event?

1. The Maunder minimum: An extreme space climate event The Maunder minimum: An extreme space climate event? Mathew Owens, Mike Lockwood, Luke Barnard, Chris Scott and Ken McCracken

2. Overview • Direct observations • Sunspots • Aurora • Cosmogenic isotope abundance • Climate observations • Reconstructions • Geomagnetic • Sunspot • Solar wind speed • Space weather implications

3. The Maunder minimumEddy, Science, 1976 • A period 1645-1715 with: • An absence of sunspots • An (apparent) reduction in auroral activity • An (apparent) reduction in coronal structure during eclipses • A reduction in 14C, suggesting increased cosmic ray flux • (10Be is now known to have increased, though still cycled)

4. Sunspot numberHoyt and Schatten, Sol Phys, 1998; Lessu et al, A&A, 2013;Svalgaard, IAU, 2011; Lockwood et al, JGR, 2014 Post 1750

5. Sunspot number: 11-year running means Post 1750

6. Aurorae.g., Siscoe, Rev Geophys, 1980

7. Cosmogenic isotope abundanceSteinhilber et al., PNAS, 2011

8. Heliospheric modulation potentialSteinhilber et al., PNAS, 2011

9. Climate records Manley, QJRMS, 1974, Lockwood et al., ERL, 2011 • No “little ice age.”

10. “closed” field line Open Solar Flux, FS Flux threading the coronal source surface UnsignedFlux, FU=  |BR| r2cos() dd r = heliocentric distance BR = radial field  = solar latitude  = solar longitude +/2 2 -/2 0 “open” field lines

11. |BR| ecliptic d R |BRE| Earth Ulysses Balogh et al., 1995; Smith et al., 2001; Lockwood et al., 2000 Ulysses showed that everywhere |BR|(d/R)2 = |BRE| Thus total unsigned magnetic flux leaving the sun = 4R2 |BRE|

12. Geomagnetic reconstructionsLockwood et al., JGR, 2014. See also Svalgaard & Cliver, JGR, 2010

13. Relation of FS and VSWLockwood & Owens, JGR, 2014

14. Relation of FS and VSW Lockwood & Owens, ApJ, 2014; Cliver & Ling, Sol Phys, 2011

15. Before 1845: FS from RSolanki et al., Nature, 2000; Owens & Crooker, JGR, 2006 • FScan be modelled as a continuity equation • dFS/dt = S – L FS • S ~ fCME ~ R

16. Loss of FSSheeley & Wang, ApJ, 2001; Owens et al., JGR, 2011

17. FS loss and the HCS tiltOwens and Lockwood, JGR, 2012

18. FS reconstructionOwens and Lockwood, JGR, 2012 FS source FS loss

19. FS reconstructionOwens & Lockwood, JGR, 2012; Lockwood & Owens, JGR, 2014 Post 1750

20. FS reconstruction (11-year)Owens & Lockwood, JGR, 2012; Lockwood & Owens, JGR, 2014 Post 1750

21. Maunder minimumOwens, et al, GRL, 2012

22. Modelling streamer belt widthSchwadron et al., ApJ, 2010; Lockwood et al., JGR 2014 • Separate streamer belt and coronal hole fluxes: • FS = FSB + FCHL = LSB + LCH • Assume: • New flux is injected into the streamer belt • Streamer belt flux eventually becomes coronal hole flux • Two coupled equations: • dFSB/dt= S - LSBFSB - SCH • dFCH/dt= SCH- LCHFCH • Streamer belt half width = sin-1 [1-FCH/FS]

23. Streamer belt widthOwens et al., JGR 2014. See also Manoharan, JGR, 2010 M. Druckmuller

24. Eclipse observationse.g., Cliver and Ling, Sol Phys, 2011

25. Streamer belt widthLockwood and Owens, JGR, 2014 Post 1750

26. Space weather“Great” geomagnetic storms, Greenwich observatory

27. Maunder minimum summary • “Extremely” low (long term) solar magnetic field, compared to sunspot era and the last 10,000 years • Increased occurrence of cold winters, but no “little ice age” • Reduced auroralfrequency, • Difficult to quantify if this was “extreme” • Polarity of the solar field continued to cycle • Coronal holes were “extremely” small and the streamer belt was “extremely” broad • Slow solar wind at Earth. • No/weak CIRs? • Continued CME activity?

28. Computing the FS loss rateOwens and Lockwood, JGR, 2012

29. PFSS solutionsMagnetic field polarity at coronal source surface

30. Three-dimensional structure of interplanetary magnetic fieldOwens et al., JGR, 2011

31. 14C & 10Be: spallation products from O, N & Ar 10Be • 1/2 = 1.5×106 yr • < qG > = 0.018 atoms cm-2s-1 14C • 1/2 = 5370 yr • < qG> = 2 atoms cm-2s-1 GALACTIC COSMIC RAYS STRATOSPHERE (2/3) TROPOSPHERE (1/3) 14C+014C0 ; 14C0+0H14C02+ H ( ~1 year) ( ~1 week) OCEANS 10Be + AEROSOL BIOMASS ICE SHEETS

32. ERA-40 Analysis of DJF temperatures & circulation (difference of high and low tercile subsets) (Woollings et al, GRL.,2010; see also Barriopedro et al., JGR, 2008) ► sorted using open solar flux FS Low solar activity gives lower surface temperatures in central England Effect much stronger in central Europe Analysis shows a distinct system to NAO

33. Central England Temperature (CET) Winter Means (DJF)  show upward drift  (linear) rate of rise dTann/dt = 0.37 C c-1

34. Frost Fairs on the Thames e.g. Winter 1683/4. Painted by Dutch artist Thomas Wijk (1616-1677) N.B. notice how warm the next year was!

35. Frost Fairs on the Thames The last one was 1813/14. Painted by Luke Clenell(1781 – 1840 )

36. Thames Freezing Over N.B. in 1825 London Bridge demolished – acted as a salt water barrage plus embankment increased flow rate

37. Thames Freezing Over 1963 Thames at Windsor