Solar Physics

, Volume 291, Issue 9–10, pp 2587–2607 | Cite as

Historical Heliophysical Series of the Ebro Observatory

  • J. J. CurtoEmail author
  • J. G. Solé
  • M. Genescà
  • M. J. Blanca
  • J. M. Vaquero
Sunspot Number Recalibration


We present the contents of the historical heliophysical series collected at the Ebro Observatory, as well as the actions carried out to restore and save these data and to conserve the physical media containing the data and the telescopes that helped to obtain them. We also discuss the results obtained with these measurements, describe how we disseminated them, and report on the investigations that we have carried out with this information. We show the evolution of the local solar indices such as the Ebro Sunspot Number (ESN), the Ebro Group Sunspot Number (EGSN), or the Ebro Sunspot Area (ESA), which are derived directly from our data. For verification purposes, these local solar indices have been compared to the international sunspot numbers published by SILSO. Our data are reliable and correlate well with the respective international series. Finally, as an example of the possibilities that the Ebro series offer, we explain the use of these data to elucidate one of the recent problems in solar physics: the discontinuity in international data known as the Waldmeier discontinuity and, in general, the ratio between sunspots and sunspot groups. In the Ebro Observatory series, no discontinuity such as this is detected. We instead observe a rather stable ratio in the spot or group rates. This result is in agreement with the hypothesis of Svalgaard (2010, ASP CS-428, 297) that the Waldmeier discontinuity is produced only on a procedural level, perhaps by a change in the criteria used in Zürich by Waldmeier or by changing external conditions.


Waldmeier’s discontinuity Heliophysical Series Group numbers International sunspot numbers Sunspot areas 



The authors wish to express their gratitude for the work done by the solar observers at the Ebro Observatory throughout its long history – a human chain that has provided an invaluable historical series of over one hundred years. We dedicate this article to all of these observers.

As regards international data, we thank the World Solar Data Centre (WDC) at the Royal Observatory of Belgium for its work in collecting, filtering, and storing the data it receives regularly from collaborating centres, and all the infrastructure it has in place for users to be able to freely download solar data from its web (SILSO).

We also thank the National Oceanic and Atmospheric Administration (NOAA), which provides a huge amount of geophysical and solar data that are essential for studies in the field of space weather and the TOSCA project (ESSEM COST action ES1005 of the European Union).

J.M. Vaquero acknowledges the support from the Junta de Extremadura (Research Group Grants GR15137) and from the Spanish Government (AYA2011-25945 and AYA2014-57556-P).


  1. Albiñana, J.: 1916a, La mayor protuberancia solar observada, Ibérica Year III, v. VI, n. 146, 247. Google Scholar
  2. Albiñana, J.: 1916b, A propósito de una protuberancia solar. Ibérica Year III, n. 129, v. V, 394. Google Scholar
  3. Altadill, D., Curto, J.J., Gaya-Piqué, Ll., Solé, G., Torta, J.M.: 2000, Coherency between solar activity and meteorologic parameters at 11 year period. In: Wilson, A. (ed.) Proc. 1st Solar and Space Weather Euroconference: The Solar Cycle and Terrestrial Climate SP-463, ESA, Noordwijk, 473. Google Scholar
  4. Aparicio, A.J., Vaquero, J.M., Gallego, M.C.: 2012, The proposed “Waldmeier discontinuity”: How does it affect to sunspot cycle characteristics? J. Space Weather Space Clim. 2, A12.  DOI. CrossRefGoogle Scholar
  5. Aparicio, A.J., Vaquero, J.M., Carrasco, V.M.S., Gallego, M.C.: 2014, Sunspot numbers and areas from the Madrid astronomical observatory (1876 – 1986). Solar Phys. 289, 4335.  DOI. ADSCrossRefGoogle Scholar
  6. Apostolov, E.M., Alberca, L.F., Altadill, D.: 1994, Solar cycle and seasonal behaviour of the quasi two and five-day oscillations in the variations of the fOF2. Ann. Geophys. 37, 187. Google Scholar
  7. Apostolov, E.M., Altadill, D., Todorova, M.: 2004, The 22-year cycle in the geomagnetic 27-day recurrences reflecting on the F2-layer ionization. Ann. Geophys. 2(2), 1171. ADSCrossRefGoogle Scholar
  8. Balcells, M.: 1908, La Observación Solar. Memorias del Observatorio del Ebro 2, G. Gili, Barcelona. Google Scholar
  9. Balmaceda, L.A., Solanki, S.K., Krivova, N.A., Foster, S.: 2009, A homogeneous database of sunspot areas covering more than 130 years. J. Geophys. Res. 114, A07104.  DOI. ADSCrossRefGoogle Scholar
  10. Cacho, J., Gil, M., Sainz de Aja, M.J., Alberca, L.F.: 1984, Possible influence of solar radiation variability on the stratospheric temperature. Adv. Space Res. 4, 37. ADSCrossRefGoogle Scholar
  11. Cardús, J.O.: 1952, Influencia de la posición heliográfica de las fulguraciones cromosféricas en la producción de corchetes geomagnéticos. Urania 231, 144. Sociedad Astronómica de España y América, Barcelona. Google Scholar
  12. Cardús, J.O.: 1983. El Observatorio del Ebro, Memoria Num. 14, Sugrañes, Roquetes. Google Scholar
  13. Cardús, J.O., Alberca, L.F.: 1978, Control estacional y por el ciclo solar de las capas ionosféricas F1 y E1. In: II Asamblea Nacional de Geodesia Y geofísica. Comunicaciones II, Comisión Nacional de Geodesia y Geofísica, D.L. Madrid, 1299. Google Scholar
  14. Cid Palacios, E.: 1960, Fulguraciones cromosféricas y sus relaciones con los fenómenos magnéticos. Urania 252, 157. Sociedad Astronómica de España y América, Barcelona. Google Scholar
  15. Cirera, R.: 1906, Noticia del Observatorio del Ebro y de Algunas Observaciones del Eclipse de 30 de Agosto de 1095. Memorias del Observatorio del Ebro, No. 1, G. Gili, Barcelona. Google Scholar
  16. Cirera, R., Balcells, M.: 1907a, Étude des rapports entre l’activité solaire et les variations magnétiques et eléctriques enregistrées à Tortose (Espagne). C. R. Séances Acad. Sci., Sér. 1 Math. 144(18), 959. Google Scholar
  17. Cirera, R., Balcells, M.: 1907b, Remarques sur le rapport entre l’activité solaire et les perturbations magnétiques. C. R. Séances Acad. Sci., Sér. 1 Math. 145(21), 862. Google Scholar
  18. Clette, F., Berghmans, D., Vanlommel, P., van der Linden, R.A.M., Koeckelenbergh, A., Wauters, L.: 2007, From the Wolf number to the International Sunspot Index: 25 years of SIDC. Adv. Space Res. 40, 919. ADSCrossRefGoogle Scholar
  19. Clette, F., Lefèvre, L.: 2016, The new Sunspot Number: assembling all corrections. Solar Phys. in press, arXiv. Google Scholar
  20. 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. ADSCrossRefGoogle Scholar
  21. Cortie, A.L.: 1901, On the types of sun-spot disturbances. Astrophys. J. 13, 260. ADSCrossRefGoogle Scholar
  22. Curto, J.J., Blanca, M., Martínez, E.: 2008, Automatic sunspots detection on full-disk solar images using mathematical morphology. Solar Phys. 250, 411.  DOI. ADSCrossRefGoogle Scholar
  23. Curto, J.J., Amory-Mazaudier, C., Torta, J.M., Menvielle, M.: 1994a, Solar flare effects at Ebre: Regular and reversed solar flare effects, statistical analysis (1953 to 1985), a global case study and a model of elliptical ionospheric currents. J. Geophys. Res. 9, 3945. ADSCrossRefGoogle Scholar
  24. Curto, J.J., Amory-Mazaudier, C., Torta, J.M., Menvielle, M.: 1994b, Solar flare effectes at Ebre: Unidimensional physical integrated model. J. Geophys. Res. 99, 23289. ADSCrossRefGoogle Scholar
  25. Galdón, E., Alberca, L.F.: 1970, Solar activity and total electron content correlation in the ionosphere at Tortosa. Urania 271, 229. Sociedad Astronómica de España y América, Barcelona. Google Scholar
  26. Gaya-Pique, L.R., Batlló, J.: 2000, La Secció Solar de L’Observatori de L’Ebre. In: Actes de les V trobades d’història de la Ciència i de la Tècnica 191, Societat Catalana d’Història de la Ciència i de la Tècnica, Barcelona. Google Scholar
  27. Gómez, A., Curto, J.J., Gras, C.: 2013, Evolution of sunspot’s characteristics in cycle 23. Solar Phys. 289, 91.  DOI. CrossRefGoogle Scholar
  28. Hoyt, D.V., Schatten, K.H.: 1998a, Group sunspot numbers: a new solar activity reconstruction. Solar Phys. 179, 189.  DOI. ADSCrossRefGoogle Scholar
  29. Hoyt, D.V., Schatten, K.H.: 1998b, Group sunspot numbers: a new solar activity reconstruction. Solar Phys. 181, 491.  DOI. ADSCrossRefGoogle Scholar
  30. Kilcik, A., Yurchyshyn, V.B., Abramenko, V., Goode, P.R., Ozguc, A., Rozelot, J.P., Cao, W.: 2011, Time distributions of large and small sunspot groups over four solar cycles. Astrophys. J. 731, 30. ADSCrossRefGoogle Scholar
  31. Lefèvre, L., Clette, F.: 2011, A global small sunspot deficit at the base of the index anomalies of solar cycle 23. Astron. Astrophys. 536, L11. ADSCrossRefGoogle Scholar
  32. Lyot, B.: 1933, Un monochromateur à grand champ utilisant les interferences en lumière polarisée. C. R. Math. 197, 1593. Google Scholar
  33. Owens, B.: 2013, Slow science. Nature 495, 300. ADSCrossRefGoogle Scholar
  34. Pericas, J.: 1912, Algunas instrucciones para medir la posición de las manchas y fáculas solares por medio de gráficas. Bol. Soc. Astron. Barc. Año III 23, 5. Google Scholar
  35. Pericas, J.: 1914, Tres Ábacos para las Mediciones Heliográficas. Memoires de l’Observatoire de l’Ebre 5, 1. Google Scholar
  36. Príncep-Curto, J.M.: 1947, Las fulguraciones cromosféricas y sus efectos inmediatos sobre el campo magnético terrestre. Urania 32(217), 1, 2. Google Scholar
  37. Puig, I.: 1927, El Observatorio del Ebro: Idea General Sobre el Mismo, Algueró y Baiges, Tortosa. Google Scholar
  38. Rodés, L.: 1928, Sur une nouvelle méthode pour mesurer la parallaxe solaire. C. R. Math. 187(13), 527. Google Scholar
  39. Rodés, L.: 1929a, Una Nueva Determinación de la Distancia Solar, Algueró y Baiges, Tortosa. zbMATHGoogle Scholar
  40. Rodés, L.: 1929b, Un nuevo índice de actividad solar. In: XII Congreso de la Asociación Española Para el Progreso de las Ciencias, Barcelona, 20 – 27 Mayo 1929, Huelves, Madrid. Google Scholar
  41. Rodés, L.: 1936, Resumen 1910 – 1934. Cuadros sinópticos. Estadísticas y resultados referentes a 25 años de Observación, Fascículo I. Heliofísica. Bol. Obs. Ebro XXV, 18. Moderna del Ebro de Algueró y Baiges, Tortosa. Google Scholar
  42. Romañá, A.: 1945, Nuevas orientaciones en el estudio del período undecenal y en el pronóstico de la actividad solar. Urania 210, 39. Sociedad Astronómica de España y América, Barcelona. Google Scholar
  43. Romañá, A.: 1947, Nota relativa a la actividad solar y geomagnética. Rev. Geofís. 23, 458. Consejo Superior de Investigaciones Científicas, Madrid. Google Scholar
  44. Romañá, A., Torroja, J.M.: 1948, El Predominio de las Manchas Solares al Este del Meridiano Central y la Inclinación de Sus Ejes Hacia el Oeste, Urania 218, 1. Sociedad Astronómica de España y América, Barcelona. Google Scholar
  45. Svalgaard, L.: 2010, Updating the historical sunspot record. In: Cranmer, S.R., Hoeksema, J.T., Kohl, J.L. (eds.) SOHO-23: Understanding a Peculiar Solar Minimum CS-428, Astron. Soc. Pac., San Francisco, 297. Google Scholar
  46. Turmon, M., Pap, J.M., Mukhtar, S.: 2002, Statistical pattern recognition for labeling solar active regions: Application to SOHO/MDI imagery. Astrophys. J. 568, 396. ADSCrossRefGoogle Scholar
  47. Vaquero, J.M.: 2007, Historical sunspot observations: A review. Adv. Space Res. 40, 929. ADSCrossRefGoogle Scholar
  48. Waldmeier, M.: 1947, Heliographische Karten der Photosphäre für das Jahr 1946, Publ. Eidgenöss. Sternwarte Zür. 9(1), 2. Google Scholar
  49. Wolf, R.: 1851, Sonnenflecken Beobachtungen in der zweiten Hälfte des Jahres 1850. Mitt. Nat.forsch. Ges. Bern 207, 89. Google Scholar
  50. Wolf, R.: 1856, Mitteilungen über die Sonnenflecken, I. Astron. Mitt. Eidgenöss. Sternwarte Zür. 1, 3. ADSGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2016

Authors and Affiliations

  • J. J. Curto
    • 1
    Email author
  • J. G. Solé
    • 1
  • M. Genescà
    • 1
  • M. J. Blanca
    • 1
  • J. M. Vaquero
    • 2
  1. 1.Observatori de l’Ebre (OE)CSIC, Universitat Ramon LlullRoquetesSpain
  2. 2.Departamento de FísicaUniversidad de ExtremaduraMéridaSpain

Personalised recommendations