1. WP2 @ ROB: SUNSPOTS CATALOGS SOLID First Annual Meeting Oct. 14-18 2013 Laure Lefèvre Royal Observatory of Belgium

2. Collecting Data Survey of existing sunspot catalogs: “standardization” of parameters

3. Catalogs Datasets Time Coverage Important parameters Missing parameters Different standards STANDARDS VARY GREATLY

4. The Debrecen Photoheliographic Data (DPD)  A very detailed dataset NOAA 7815

5. USAF/MtWilson data  Taken within the Solar Optical Observing network (SOON)  Military personnel around the world observing sunspot groups on a day to day basis  Less details (no individual sunspot information), but information about the classes of the groups  Goal is space weather purposes (so a tendency to omit the smallest spots)  Goes back to 1 st Dec. 1981 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 5

6. RGO data  Starts in 1874 and stops in Aug. of 1982  Overlap with SOON of about 9 months.  Information about sunspot groups (no individual sunspots).  Local group class with numbers 0 to 9: relation with McIntosh classes unclear  Can follow groups during one solar rotation with local number from Greenwich before 1976, NOAA group number after 1976  No number of spots in group, no information on individual sunspots 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 6

7. USET data  Drawings from Uccle start in 1940  Zurich and McIntosh classes are used  No areas yet (TBI)  Number of spots in groups  A few of the oldest years remain to be analyzed 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 7

8. Merging/MATCHING cATALOGS Back to the 1960s … and farther 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 8

9. Testbed case: DPD+USAF  Last 2 solar cycles (1986-2011) – NOW 1980-2011  Very detailed dataset: group and spots information  Modified Zurich morphological types 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 9 DPD USAF

10.  Survey and Merging of Sunspot Catalogs, Lefèvre & Clette (2012) 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 10

11. RGO+USET database  RGO : 1874 – 1982  USET: 1940 – now  First preliminary catalog/matching done.  Fit is already very good. 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 11

12. Linking the different catalogs  Possible to compare the different parameters (areas, grouping, classification) of groups on approx. 3 years 1980-1982 in the merged RGO+USET and merged USAF+DPD or the different catalogs between themselves.  Statistical study  Provides correspondence parameters between these different datasets.  In the end: Homogeneous dataset with encountered problems and reliability/quality assessment. 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 12

13. First quality assessment: Comparing USET and USAF catalogs 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 13

14. USAF extent ≈ 1.5 USET extent 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 14

15. Using these catalogs as input For reconstructions 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 15

16. They can help to construct better proxies of the SSI  At least until 1965 for this call… but maybe we can go even farther back.  CaIIK images and indices go as far as 1942 at McMath (1942- 1987) – Sacramento Peak : 1976 – 2002, and SFO: most recent (up to now).  RGO data go as far back as 1874, but its complementary catalog (USET) goes as far back as 1940.  We could easily reconstruct sunspot and Calcium data back to 1942 in fact. 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 16 …by recreating details of the surface of the Sun for as long as these sunspot parameters exist.

17. A little preview: The highest level of details 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 17 33 years with the merged USAF/DPD catalog with information down to single sunspots … and its caveats

18. Distribution of spots in DDC 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 18 Distance to Disk Center (R/R  )

19. A closer look 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 19

20. How does it work? 10/2013 20

21. Number of spots of different sizes in different slices of the Sun’s disk 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 21 SMALL MEDIUM LARGE V. LARGE ALL

22. Added bonus of these catalogs Going beyond the traditional 1D series of the International Sunspot Number. 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 22

23. They can help understand the long term evolution of the Sun Recent peculiarities of cycle 23-24 …by studying in details the peculiarities of the last solar cycles. F10.7 compared to ISSN

25. Obviously something happened  Why did different time series start to become erratic at the same time? …but what exactly?

26. Let’s take a closer look into these detailed properties 02/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 26 Each group is counted only once: when it reaches its maximum area. Ratios are for max22 (1989-1991) and max23 (2000-2002). r A =2.4±0.5 r B = 2.5±0.4 r C =1.2 ± 0.2 r D =1±0.2 r E =1±0.2 r F =0.8 ±0.3 Lefèvre & Clette (2011)

27. An even closer look 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 27 Small spots: U+P ≤ 17 msh AND (U+P)/U ≤ 7 Smallest spots in groups Lefèvre & Clette (2011)

28. Small spots: Lifetime of groups Cycle 22 Cycle 23 A FED C B Lefèvre & Clette (2011)

29. Distribution of Spot Sizes between solar cycles 22 and 23 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 29 Cycle 22 Cycle 23

30. Cycle 23 and vanishing spots: declining field strength  Livingston-Penn effect (Livingston & Penn 2009, 2012; Penn & Livingston 2006, ) :  Average core magnetic field in umbra (FeI line: 1565 nm)  Steady decline since 2000 : Magnetic field: -40 G/year  Existence of a lower threshold: 1500 G  Decline of the small- sunpot formation fraction 30 Livingston et al. 2012 No more spots in 2030 ?

31. Cycle 23 and vanishing spots: a shallow internal change  BISON helioseismic sounding 1978- 2012 (Basu et al. 2013) :  Solar-cycle induced modulation of p-mode frequencies in the near- surface layers  Top layers (high-frequency modes) : discrepancy starting in 1998  Deeper layer (r < 0.997 r ʘ ) (low frequency modes) : deviation during entire cycle 23  Thinning of the subsurface magnetic field layer (< 20000 km) 31

32. Cycle 23 and vanishing sunspots: spots per group  Same trend deduced for different stations and data sets  Apparent secular variations of the number of spots per group:  Increase for stronger cycles (Tlatov 2013, Nagovitsyn et al. 2012)  Caveat: Ratio of distinct series based on different sets of raw observations.  SSN and group number are two distinct physical quantities.  Varying relation = physical information 32 Tlatov 2013 SONNE, A. Bulling, L. Svalgaard 2013 SONNE SSN Locarno SSN

33. It appears the Sun switched to a new regime sometime during cycle 23  In this new regime, the usual proxy relations do not seem to hold any longer. 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 33

34.  Thank you 10/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 34

35. In the context of the SOLID project (WP2)  Task 2.3: Ground-based proxies for SSI (ROB, CNRS). Continuous spectral irradiance variations in the near ultraviolet and visible only exist since very recently, which makes the use of ground based proxy compulsory. SSI modelling in this spectral range has relied exclusively on sunspot and faculae indicators, usually derived from solar images. This task will investigate other ground-based measurements that have the potential to provide excellent proxies to SSI variations at these wavelengths. Recently available information on sunspots (group, class,..,) over solar cycle 23 and 24 will be extended and these data will be carefully analysed and compared with SSI and TSI variations over the time where space measurement exists. Additionally, other proxies and proxy-based SSI reconstructions obtained in WP4 and WP5 will be checked again with the SSI data to enforce quality and collaboration between WPs. 02/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 35

36. Disagreements seem to be caused by a decrease in numbers of the smallest sunspots  The small sunspot deficit naturally explains the discrepancies between R i and other indices that put less weight on the smallest magnetic features. In particular the fact that the F10.7 does not represent the solar EUV flux during the last minimum.  It reveals an anomaly in cycle 23, begun long before the new cycle, that suggests the Sun switched to a new regime.  Cycle 23 shares properties with cycles of the 19 th and early 20 th century. Did such a small spot deficit occur for those cycles ? Can it explain some enduring discrepancies between historical index series (R i vs. R G, Sunspot area, aa) ? 02/2013SOLID Meeting, ORLEANS. 14-18 Oct. 2013 36