Recalibration of the sunspot-number : status report
Clette, F.; Lefèvre, L.; Chatzistergos, T.; Hayakawa, H.; Carrasco, V. M. S.; Arlt, R.; Cliver, E. W.; Dudok de Wit, T.; Friedli, T. K.; Karachik, N.; Kopp, G.; Lockwood, M.; Mathieu, S.; Muñoz-Jaramillo, A.; Owens, M.; Pesnell, D.; Pevtsov, A.; Svalgaard, L.; Usoskin, I. G.; van Driel-Gesztelyi, L.; Vaquero, J. M. (2023-03-20)
Clette, F., Lefèvre, L., Chatzistergos, T. et al. Recalibration of the Sunspot-Number: Status Report. Sol Phys 298, 44 (2023). https://doi.org/10.1007/s11207-023-02136-3
© 2023 The Authors. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
https://creativecommons.org/licenses/by/4.0/
https://urn.fi/URN:NBN:fi-fe20230925136474
Tiivistelmä
Abstract
We report progress on the ongoing recalibration of the Wolf sunspot number (SN) and group-sunspot number (GN) following the release of version 2.0 of SN in 2015. This report constitutes both an update of the efforts reported in the 2016 Topical Issue of Solar Physics and a summary of work by the International Space Science Institute (ISSI) International Team formed in 2017 to develop optimal SN and GN reconstruction methods while continuing to expand the historical sunspot-number database. Significant progress has been made on the database side while more work is needed to bring the various proposed SN and (primarily) GN reconstruction methods closer to maturity, after which the new reconstructions (or combinations thereof) can be compared with (a) “benchmark” expectations for any normalization scheme (e.g., a general increase in observer normalization factors going back in time), and (b) independent proxy data series such as F10.7 and the daily range of variations of Earth’s undisturbed magnetic field. New versions of the underlying databases for SN and GN will shortly become available for years through 2022 and we anticipate the release of the next versions of these two time series in 2024.
Kokoelmat
- Avoin saatavuus [37744]