J/A+A/639/A88 Plage area composite series (Chatzistergos+, 2020)
Analysis of full-disc Ca II K spectroheliograms.
III. Plage area composite series covering 1892-2019.
Chatzistergos T., Ermolli I., Krivova N.A., Solanki S.K., Banerjee D.,
Barata T., Belik M., Gafeira R., Garcia A., Hanaoka Y., Hegde M., Klimes J.,
Korokhin V.V., Lourenco A., Malherbe J.-M., Marchenko G.P., Peixinho N.,
Sakurai T., Tlatov A.G.
<Astron. Astrophys. 639, A88 (2020)>
=2020A&A...639A..88C 2020A&A...639A..88C (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Sun
Keywords: Sun: activity - Sun: photosphere - Sun: chromosphere -
Sun: faculae, plages
Abstract:
Studies of long-term solar activity and variability require knowledge
of the past evolution of the solar surface magnetism. An important
source of such information are the archives of full-disc CaII K
observations performed more or less regularly at various sites since
1892.
We derive the plage area evolution over the last 12 solar cycles
employing data from all CaII K archives available publicly in digital
form known to us, including several as yet unexplored CaII K archives.
We analyse more than 290000 full-disc CaII K observations from 43
datasets spanning the period 1892-2019. All images were consistently
processed with an automatic procedure that performs the photometric
calibration (if needed) and the limb-darkening compensation. The
processing also accounts for artefacts plaguing many of the images,
including some very specific artefacts such as bright arcs found in
Kyoto and Yerkes data. The employed methods have previously been
tested and evaluated on synthetic data and found to be more accurate
than other methods used in the literature to treat a subset of the
data analysed here.
We have produced a plage area time-series from each analysed dataset.
We found that the differences between the plage areas derived from
individual archives are mainly due to the differences in the central
wavelength and the bandpass used to acquire the data at the various
sites. We have empirically cross-calibrated and combined the results
obtained from each dataset to produce a composite series of plage
areas. "Backbone" series are used to bridge all the series together.
We have also shown that the selection of the backbone series has
little effect on the final plage area composite. We have quantified
the uncertainty of determining the plage areas with our processing due
to shifts in the central wavelength and found it to be less than 0.01
in fraction of the solar disc for the average conditions found on
historical data. We also found the variable seeing conditions during
the observations to slightly increase the plage areas during activity
maxima.
We provide the so far most complete time series of plage areas based
on corrected and calibrated historical and modern CaII K images.
Consistent plage areas are now available on 88% of all days from 1892
onwards and on 98% from 1907 onwards.
Description:
Annual, monthly, and daily values of the plage area composite series.
The archives included are those from the Arcetri (Ar), Baikal (Ba),
Brussels (Br), Calern (CL), Catania (CT), Coimbra (Co), Kanzelhoehe
(Ka), Kenwood (Ke), Kharkiv (Kh), Kislovodsk (Ki), Kodaikanal taken
with the spectroheliograph (Ko), Kodaikanal taken with the Twin
telescope (KT), Kodaikanal taken with the White-Light Active Region
Monitor (WARM) telescope (KW), Kyoto (Ky), Manila (Ma), Mauna Loa (ML)
taken with the Precision Solar Photometric Telescope (PSPT),
McMath-Hulbert (MM), Mees (MS), Meudon taken with the
spectroheliograph (MD1), Meudon taken with an interference filter
(MD2), Mitaka taken with the spectroheliograph (Mi1), Mitaka taken
with the Solar Flare Telescope with an interference filter (Mi2), Mt
Wilson (MW), Pic du Midi (PM), SOlar Diameter Imager and Surface
Mapper (SODISM) telescope on board the PICARD spacecraft (PS), Rome
taken with the equatorial bar at Monte Mario (Ro), Rome taken with the
PSPT (RP1), Rome taken with the PSPT with narrow bandwidth (RP2),
Sacramento Peak (SP), San Fernando taken with the Cartesian Full-Disk
Telescope (CFDT) 1 (SF1), San Fernando taken with the CFDT2 (SF2),
Schauinsland (Sc), Teide (Te) taken with the Chromospheric Telescope
(ChroTel), Upice (UP), Valasske Mezirici (VM), Wendelstein (WS), and
Yerkes (YR) sites
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
comp_y.dat 20 128 Plage series, annual values
comp_m.dat 25 1536 Plage series, monthly values
comp_d.dat 30 46751 Plage series, daily values
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See also:
VI/138 : Sunspots catalogues, 1853-1870 (Casas+, 2013)
J/A+A/390/707 : Hemispheric Sunspot Numbers 1975-2000 (Temmer+, 2002)
J/A+A/447/735 : Hemispheric Sunspot Numbers 1945-2004 (Temmer+, 2006)
J/A+A/584/A73 : Sunspot areas and tilt angles (Senthamizh Pavai+, 2015)
J/A+A/595/A104 : Scheiner drawing sunspot areas and tilt angles (Arlt+, 2016)
J/A+A/602/A69 : Group sunspot number series since 1739 (Chatzistergos+, 2017)
J/A+A/625/A69 : Plage area composite series (Chatzistergos+, 2019)
Byte-by-byte Description of file (#): comp_y.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 yr Year Year of observation
6- 12 F7.3 --- plagedf ?=-99 Projected plage areas in disc fraction (1)
14- 20 F7.3 --- plagemh ?=-99 Corrected for foreshortening plage areas
in microhemispheres (1)
--------------------------------------------------------------------------------
Note (1): missing values are denoted with -99.
-------------------------------------------------------------------------------
Byte-by-byte Description of file (#): comp_m.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 yr Year Year of observation
8- 9 I2 "month" Month Month of observation
11- 17 F7.3 --- plagedf ?=-99 Projected plage areas in disc fraction (1)
19- 25 F7.3 --- plagemh ?=-99 Corrected for foreshortening plage areas
in microhemispheres (1)
--------------------------------------------------------------------------------
Note (1): missing values are denoted with -99.
-------------------------------------------------------------------------------
Byte-by-byte Description of file (#): comp_d.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 I4 yr Year Year of observation
8- 9 I2 "month" Month Month of observation
13- 14 I2 d Day Day of observation
16- 22 F7.3 --- plagedf ?=-99 Projected plage areas in disc fraction (1)
24- 30 F7.3 --- plagemh ?=-99 Corrected for foreshortening plage areas
in microhemispheres (1)
--------------------------------------------------------------------------------
Note (1): missing values are denoted with -99.
-------------------------------------------------------------------------------
Acknowledgements:
Theodosios Chatzistergos, chatzistergos(at)mps.mpg.de
References:
Chatzistergos et al., Paper I 2018A&A...609A..92C 2018A&A...609A..92C
Chatzistergos et al., Paper II 2019A&A...625A..69C 2019A&A...625A..69C, Cat. J/A+A/625/A69
(End) Theodosios Chatzistergos [MPS], Patricia Vannier [CDS] 05-May-2020