rob: sunspots catalogs solid first annual meeting oct. 14-18 2013 laure lefèvre royal observatory...

WP2 @ ROB: SUNSPOTS CATALOGS

SOLID First Annual Meeting

Oct. 14-18 2013

Laure LefèvreRoyal Observatory of Belgium

Collecting DataSurvey of existing sunspot catalogs: “standardization” of parameters

PARAMETERS Units SGD CATANIA

MWILSONKandilli

TashkentUSAF

VoroshilovUSNO

Boulder

TAIPEI USSR YUNNAN RGO KODAIKANAL ROME DEBRECEN

DPDDEBRECEN

SDD ROB Total Time Coverage

Time Coverage Begin – end

1969-1982

1978-1999

1927-2011

1964-1994

1968-1991

1981-1992

1874-1982

1906-1987

1958-2000

1980-2013

1996-2008

1940-2013

1874-2013

Number of years 14 22 84 31 24 12 119 82 43 33 13 73 139

Date Y,m,d,UT MAX

Area P, Projected (msd)C, Corrected

(msh)U, U+P

U+P, c U+P,p,c U+P, c(1981-2009)

U, cU+P, p,c

U+P,c +sq degrees

U+P, p,cLargest spot

U,U+P, p,c> 1976 no

U

Up,cmicrohemisphere (msh)

U,U+P,p,c U,U+P,p,cIndividual

Spots areas

U,U+P, p,c MAX

Number of spots

(1981-2009) 106

Distance from disk center

0 to 1 r/R MAX

Central Meridian Distance

Degrees :LCM, CMA

MAX

Latitude degrees MAX

Longitude degrees MAX

Group's Polar Angle

degrees,position of the gp relative

to north pole

Group's polar angle

Group's polar angle

Group's polar angle

43

Position Angle P, Bo, Lo : references

Polar angle 0 to 360

Position of pole

Position of pole

P,B,L MAX

ID number NOAA, or local IDs

MtWIL MtWIL+NOAA

local local local Local < 1976

local NOAA NOAA MAX

Morphological classification

Zurich, McIntosh, or other USNO

1968-1971 (Waldmeier)

Local < 1976

MAX

Image quality 1..5 Standards vary

0....10 (better)

106

CatalogsDatasetsTime

Coverage

Important parameters Missing

parametersDifferent standards

STANDARDS VARY

GREATLY

The Debrecen Photoheliographic Data (DPD) A very detailed dataset

NOAA 7815

SOLID Meeting, ORLEANS. 14-18 Oct. 2013

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 1st Dec. 1981

10/2013


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

10/2013


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

10/2013


8

Merging/MATCHING cATALOGSBack to the 1960s … and farther

10/2013


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

10/2013

DPD USAF


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Survey and Merging of Sunspot Catalogs, Lefèvre & Clette (2012)

10/2013


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RGO+USET database

RGO : 1874 – 1982 USET: 1940 – now First preliminary catalog/matching done. Fit is already very good.

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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.

10/2013


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First quality assessment: Comparing USET and USAF catalogs

10/2013


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USAF extent ≈ 1.5 USET extent10/2013


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Using these catalogs as inputFor reconstructions

10/2013


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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.

10/2013

…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

10/2013

33 years with the merged USAF/DPD catalog with information down to single sunspots … and its caveats


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Distribution of spots in DDC

10/2013

Distance to Disk Center (R/R)


19

A closer look

10/2013

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How does it work? 10/2013


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Number of spots of different sizes in different slices of the Sun’s disk

10/2013

SMALL MEDIUM LARGE V. LARGE ALL


22

Added bonus of these catalogsGoing beyond the traditional 1D series of the International Sunspot Number.

10/2013

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

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

02/2013

Each group is counted only once: when it reaches its maximum area. Ratios are for max22 (1989-1991) and max23 (2000-2002).

rA=2.4±0.5

rB= 2.5±0.4

rC=1.2 ± 0.2

rD=1±0.2

rE=1±0.2

rF=0.8 ±0.3

Lefèvre & Clette (2011)


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An even closer look10/2013

Small spots: U+P ≤ 17 msh AND (U+P)/U ≤ 7

Smallest spots in groups


Small spots: Lifetime of groupsCycle 22Cycle 23

A

FED

CB



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Distribution of Spot Sizes between solar cycles 22 and 23

10/2013

Cycle 22Cycle 23

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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

Livingston et al. 2012

Livingston et al. 2012

Livingston et al. 2012 No more spots in 2030 ?

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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 rʘ) (low frequency modes): deviation during entire cycle 23

Thinning of the subsurface magnetic field layer (< 20000 km)

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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

Tlatov 2013

SONNE, A. Bulling, L. Svalgaard 2013

SONNE SSN

Locarno SSN

19 20 21 22 23 249

1011121314

Ri/Rg Nagovitsyn


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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.

10/2013


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Thank you

10/2013


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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.

02/2013


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Disagreements seem to be caused by a decrease in numbers

of the smallest sunspots The small sunspot deficit naturally explains the discrepancies

between Ri 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 19th and early 20th century. Did such a small spot deficit occur for those cycles ? Can it explain some enduring discrepancies between historical index series (Ri vs. RG, Sunspot area, aa) ?

02/2013

rob: sunspots catalogs solid first annual meeting oct. 14-18 2013 laure lefèvre royal observatory...

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