WDC-SILSO: An unprecedented modernization of the sunspot record - - PowerPoint PPT Presentation

WDC-SILSO: An unprecedented modernization

• f the sunspot record

Frédéric Clette, Laure Lefèvre

World Data Center SILSO, Royal Observatory of Belgium, Brussels ROB STCE

Sunspot number: origins and applications

• Longest record of solar activity (400 years)
• Historical observations back to 1610 (telescope)
• Continuously extended: worldwide network of 85 stations
• Unique long-term reference: > 100 publications/year:

– Solar physics (physical modeling of solar 11-year cycle) – Climatology (secular solar forcing to Earth climate) – Industry and defense: telecoms, navigation, space, electrical power

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SPACE CCD RADIO PHOTOGRAPHY TELESCOPE: VISUAL GRAND MINIMUM (Maunder)

SMALL MINIMUM

(Dalton)

SILSO data products and Web portal

• Sunspot Number

(1700-present):

– Daily, monthly, yearly – Total and hemispheric

• Mid-term forecasts:

– 12-months ahead – 2 methods

• New products:

– Group Number (1610 – 1995):

• Only group counts

– Real-time Estimated Sunspot Number (EISN)

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A full modernization

• New Web site (January 2015):

– Data documentation, FAQ – New improved graphics – Ready for extensions

• Refurbished software and archives:

– FORTRAN to Python code (bug fixes!) – Databases (MySQL): > 530,000 obs. – Web-based data input GUI

• Full recalibration of

the primary sunspot number series:

– First-ever full revision ! – Undertaken in 2011 – 50 international experts – 4 workshops

• Corrections by up to 40%

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First-ever end-to-end recalibration

• Review paper:

Clette, F., Svalgaard, L., Vaquero, J.M., Cliver, E.W.: 2014, Revisiting the Sunspot Number. A 400-Year Perspective on the Solar Cycle. Space Sci. Rev. 186, 35-103

• Official release in July

2015

– IAU General Assembly (Aug. 8, 2016)

• Implementation of data

set versioning

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• Full revival of long-term solar cycle research:

– Topical Issue (“Solar Physics” journal): Publ.: December 2016 > 40 papers, 800 pages – Since 2014, publication of multiple alternate sunspot series by various teams

A profound transition: multiple new roles

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Static unquestioned archive Modern evolving data set

Formerly (Zurich, SIDC)

Repository + extension of the heritage series (frozen method)

Now (WDC –SILSO)

Clearinghouse for all new published results (whole series)

• Central hub for input sunspot data (database of all raw observations)
• Coordinated evaluation of future proposed corrections (IAU supervision)
• Upgrade of the production method to follow progresses

The future: bright but uncertain

• Promising prospects:

– Full quality assurance – Extension by image- based sunspot indices (sunspot catalogs)

• But … SILSO in a

precarious situation!

– No structural funding – Insufficient manpower

(team of only 3 part-time collaborators)

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Zharkova et al. EGSO, 2003 DigiSun drawing measurement tool

ROB, Brussels

Questions or suggestions ?

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World Data Center – SILSO

Sunspot Index and Long-term Solar Observations

Poster # 61

http://sidc.be/silso