observaciones solares de tiempos pretéritos: un reto para la heliofísica de hoy
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IV Reunión Española de Física Solar y Heliosférica Presente y futuro: infraestructura observacional y explotación científica Alcalá de Henares, 19-21 Jun 2013. Observaciones solares de tiempos pretéritos: un reto para la heliofísica de hoy. J. M. Vaquero Centro Universitario de Mérida - PowerPoint PPT PresentationTRANSCRIPT
Observaciones solares de tiempos pretéritos: un reto para la
heliofísica de hoy
J. M. VaqueroCentro Universitario de Mérida
Universidad de Extremadura, Spain
IV Reunión Española de Física Solar y Heliosférica Presente y futuro: infraestructura observacional y explotación científica
Alcalá de Henares, 19-21 Jun 2013
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Reasons Why the SSN Needs Re-examination
• It’s used… for important aplications:– Long-term solar variability.– Solar dynamo modeling.– Climate change.
• We have two Sunspot Numbers.
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The ratio of the Group to Zurich SSN has two significant discontinuities
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Vaquero (2007) Adv. Spa. Res. 40, 929.
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Relationship between GSN and AD for all available data from Hoyt & Schatten (1998). The inset presents an enlarged version but restricted to values AD < 35%.
Vaquero et al. (2012) Solar Phys. 277, 389
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Vaquero et al. (2011) ApJL 731, L24.
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Hoyt & Schatten (1998)This talk
Vaquero & Trigo (2013), in progress
“Great Gap”
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Can we detect the solar cycle in the Hoyt & Schatten Database?
• Hoyt & Schatten Database is contaminated with “zero” values of SN derived from solar-astrometric observations (solar altitude, solar radius, …).
• As an example, we can cite the observations made with the great meridian lines (camera obscura).
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Can we detect the solar cycle in the Hoyt & Schatten Database?
I have designed a "new" database (extracted from HS98). The purpose is to use only reliable observations to pinpoint AD and NAD. I have only chosen (for each year) observers with recorded AD.
HS98
64 Observers
19358 days with records
402 Active days
HS98 modified
36 Observers
4141 days with records
402 Active days
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Can we detect the solar cycle in the Hoyt & Schatten Database?
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Can we detect the solar cycle in the Hoyt & Schatten Database?
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Using a 5-year moving-average window and assuming a hyper-geometrical probability distribution… 14
Some conclusions• In the last few years, three major changes in H&S98 database have
been proposed:– Onset of Maunder Minimum (Vaquero et al., 2011).– Solar Cycle -1 (Vaquero et al., 2007; Vaquero & Trigo, 2013)– Lost solar cycle (Usoskin et al., 2009; Zolotova & Ponyavin, 2011).
• There is interesting lost solar information that is preserved in archives and libraries. We need a “Sunspot/Solar Historical Archive”.
• Maunder minimum was a period of very low sunspot numbers as Hoyt & Schatten stated. However, their values probably are understimated because they used astrometric observation records (including camera obscura records!). Most likely, the solar cycle is present in sunspot data.
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