Series of classical solar activity indices: Kislovodsk data

Nagovitsyn, Yu. A.; Makarova, V. V.; Nagovitsyna, E. Yu.

doi:10.1134/s0038094607010091

Cited by 12 publications

(7 citation statements)

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“…Since area measurements from different observatories show systematic differences (Fligge & Solanki 1997;Baranyi et al 2001;Balmaceda et al 2009), a cross-calibration is necessary before using them for any analysis. Various past studies have found that both the daily and the individual area measurements from the catalogues considered here (Deberecen, Kislovodsk, and Pulkovo) are very similar to each other, and also to the measurements from RGO, with mutual cross-calibration factors being close to unity (Nagovitsyn et al 2007;Balmaceda et al 2009;Baranyi et al 2013;Muñoz-Jaramillo et al 2015;Mandal et al 2020). For the purpose of this work we use the latest calibration by Mandal et al (2020) who compared these datasets statistically during the overlapping periods to generate a consistent and homogeneous area record.…”

Section: Methodsmentioning

confidence: 69%

“…We use sunspot area catalogues from three different sources, namely Debrecen Observatory 1 (Baranyi et al 2016;Győri et al 2017), Kislovodsk Mountain station 2 (Nagovitsyn et al 2007), and Pulkovo observatory 3 (Mikhailov 1955). The Kislovodsk (1954Kislovodsk ( -2019 and Pulkovo (1932Pulkovo ( -1991 catalogues provide daily records of the total area of every individual group, A group (including umbrae and penumbrae), the total area of the biggest spot, A big_spot (including umbra and penumbra), as well as the number, N, of individual umbrae in each group.…”

Section: Methodsmentioning

confidence: 99%

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On the size distribution of spots within sunspot groups

Mandal

Krivova

Cameron

et al. 2021

A&A

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The size distribution of sunspots provides key information about the generation and emergence processes of the solar magnetic field. Previous studies of size distribution have primarily focused on either the whole group or individual spot areas. In this paper we investigate the organisation of spot areas within sunspot groups. In particular, we analysed the ratio (R) of the area of the biggest spot (Abig_spot) inside a group, to the total area of that group (Agroup). We used sunspot observations from Kislovodsk, Pulkovo, and Debrecen observatories, together covering solar cycles 17–24. We find that at the time when the group area reaches its maximum, the single biggest spot in a group typically occupies about 60% of the group area. For half of all groups, R lies in the range between roughly 50% and 70%. We also find R to change with Agroup, such that R reaches a maximum of about 0.65 for groups with Agroup ≈ 200 μHem and then remains at about 0.6 for larger groups. Our findings imply a scale-invariant emergence pattern, providing an observational constraint on the emergence process. Furthermore, extrapolation of our results to larger sunspot groups may have a bearing on the giant unresolved starspot features found in Doppler images of highly active Sun-like stars. Our results suggest that such giant features are composed of multiple spots, with the largest spot occupying roughly 55–75% of the total group area (i.e., the area of the giant starspots seen in Doppler images).

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Section: Methodsmentioning

confidence: 69%

Section: Methodsmentioning

confidence: 99%

On the size distribution of spots within sunspot groups

Mandal

Krivova

Cameron

et al. 2021

A&A

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“…The next two datasets listed in Table 1 come from the Kislovodsk (1952Kislovodsk ( -2018 3 (Nagovitsyn et al 2007) and Pulkovo (1932Pulkovo ( -1991 observatories (Mikhailov 1955). The Pulkovo Observatory, originally established at 1839 with the aim of cataloging the positions of stars, started accumulating solar images (photosphere and chromosphere) in 1932.…”

Section: Datamentioning

confidence: 99%

“…Their "b" values are also similar (see Table 2). However observations from Kislovodsk are considered to be better suited for the extension of RGO because of the stable background history of this catalog (Nagovitsyn et al 2007). The other advantage of the Kislovodsk record over Pulkovo is that it offers an additional 28 years of added observations beyond 1991.…”

Section: Compositementioning

confidence: 99%

Sunspot area catalog revisited: Daily cross-calibrated areas since 1874

Mandal

Krivova

Solanki

et al. 2020

A&A

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Context. Long and consistent sunspot area records are important for understanding long-term solar activity and variability. Multiple observatories around the globe have regularly recorded sunspot areas, but such individual records only cover restricted periods of time. Furthermore, there are systematic differences between these records and require cross-calibration before they can reliably be used for further studies. Aims. We produce a cross-calibrated and homogeneous record of total daily sunspot areas, both projected and corrected, covering the period between 1874 and 2019. In addition, we generated a catalog of calibrated individual group areas for the same period. Methods. We compared the data from nine archives: Royal Greenwich Observatory (RGO), Kislovodsk, Pulkovo, Debrecen, Kodaikanal, Solar Optical Observing Network (SOON), Rome, Catania, and Yunnan Observatories, covering the period between 1874 and 2019. Cross-comparisons of the individual records were done to produce homogeneous and inter-calibrated records of daily projected and corrected areas. As in earlier studies, the basis of the composite is formed by the data from RGO. After 1976, the only datasets used are those from Kislovodsk, Pulkovo, and Debrecen observatories. This choice was made based on the temporal coverage and the quality of the data. While there are still 776 days missing in the final composite, these remaining gaps could not be filled with data from the other archives as the missing days lie either before 1922 or after 2016 and none of the additional archives cover these periods. Results. In contrast to the SOON data used in previous area composites for the post-RGO period, the properties of the data from Kislovodsk and Pulkovo are very similar to those from the RGO series. They also directly overlap the RGO data in time, which makes their cross-calibration with RGO much more reliable. Indeed, comparing our area catalog with previous such composites, we find improvements both in data quality and coverage. We also computed the daily Photometric Sunspot Index, which is widely used, for example, in empirical reconstructions of solar irradiance.

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“…Sarychev and Roshchina (2006) used Greenwich data to study total sunspot area as a solar activity index and, by utilising proxy data, these authors extended the series back to 1700. Nagovitsyn, Makarova, and Nagovitsyna (2007) Pelt, Korpi, and Tuominen (2010), using a nonparametric statistical analysis.…”

Section: Historical Development Of the Sunspot Database And Its Scienmentioning

confidence: 99%

The Greenwich Photo-heliographic Results (1874 – 1976): Summary of the Observations, Applications, Datasets, Definitions and Errors

et al. 2013

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The measurements of sunspot positions and areas that were published initially by the Royal Observatory, Greenwich, and subsequently by the Royal Greenwich Observatory (RGO), as the Greenwich Photo-heliographic Results (GPR), 1874-1976, exist in both printed and digital forms. These printed and digital sunspot datasets have been archived in various libraries and data centres. Unfortunately, however, typographic, systematic and isolated errors can be found in the various datasets. The purpose of the present paper is to begin the task of identifying and correcting these errors. In particular, the intention is to provide in one foundational paper all the necessary background information on the original solar observations, their various applications in scientific research, the format of the different digital datasets, the necessary definitions of the quantities measured, and the initial identification of errors in both the printed publications and the digital datasets. Two companion papers address the question of specific identifiable errors; namely, typographic errors in the printed publications, and both isolated and systematic errors in the digital datasets. The existence of two independently prepared digital datasets, which both contain information on sunspot positions and areas, makes it possible to outline a preliminary strategy for the development of an even more accurate digital dataset. Further work is in progress to generate an extremely reliable sunspot digital dataset, based on the programme of solar observations supported for more than a century by the Royal Observatory, Greenwich, and the Royal Greenwich Observatory. This improved dataset should be of value in many future scientific investigations.

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Series of classical solar activity indices: Kislovodsk data

Cited by 12 publications

References 1 publication

On the size distribution of spots within sunspot groups

On the size distribution of spots within sunspot groups

Sunspot area catalog revisited: Daily cross-calibrated areas since 1874

The Greenwich Photo-heliographic Results (1874 – 1976): Summary of the Observations, Applications, Datasets, Definitions and Errors

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