This readme file was generated on [2024-11-25] by [Anthony R. Yeates]

GENERAL INFORMATION

Title of Dataset: Historical magnetic regions from Ca II K synoptic maps

Author/Principal Investigator Information
Name: Anthony R. Yeates
ORCID: 0000-0002-2728-4053
Institution: Durham University
Address: Department of Mathematical Sciences, South Road, Durham, DH1 3LE, UK
Email: anthony.yeates@durham.ac.uk

Date of data collection: 2024-08-19

Geographic location of data collection: Durham, UK

Information about funding sources that supported the collection of the data: UKRI/STFC grant ST/W00108X/1


SHARING/ACCESS INFORMATION

Licenses/restrictions placed on the data: CC-BY

Links to publications that cite or use the data: [in preparation - reference to be added]

Links to other publicly accessible locations of the data: none

Links/relationships to ancillary data sets:
1. Digitized MWO Ca II K synoptic maps, from Bertello+2020: https://doi.org/10.7910/DVN/RQSEJ8
2. Digitized MWO sunspot data from Pevtsov+2019: https://doi.org/10.25668/bkt9-4d24
3. Sunspot data from Leussu+2021: https://doi.org/10.26093/cds/vizier.35990131
4. Polar flux estimated from faculae, from Munoz-Jaramillo+2016: https://doi.org/10.7910/DVN/KF96B2

Was data derived from another source?
If yes, list source(s): See links above.

Recommended citation for this dataset: Yeates, A.R. (2024): Historical magnetic regions from Ca II K synoptic maps [dataset].  Durham University.  DOI:  http://doi.org/10.15128/r33f462541f


DATA & FILE OVERVIEW

File List: 
regions-full_hale_x20.zip – magnetic region files for 20 realizations of the plage flux+polarity assignment [see paper for details]. This version uses no sunspot data, but fills all polarities using Hale's Law. "Bad" regions (with incomplete Ca II K observations) have been separated into a sub-folder.
regions-full_spots_x20.zip – same but with sunspot measurements used to aid polarity assignment.
regions-nso_hale_x10.zip – same but for only the period with overlapping magnetogram observations, and only 10 realizations. All polarities filled using Hale's Law.
regions-nso_spots_x10.zip – same but for only the period with overlapping magnetogram observations, and only 10 realizations. Sunspot measurements used to aid polarity assignment.

Relationship between files, if important: described above

Additional related data collected that was not included in the current data package: none

Are there multiple versions of the dataset? No
If yes, name of file(s) that was updated: 
Why was the file updated? 
When was the file updated? 


METHODOLOGICAL INFORMATION

Description of methods used for collection/generation of data: <include links or references to publications or other documentation containing experimental design or protocols used in data collection>
Python code used to generate the dataset is available at https://doi.org/10.5281/zenodo.14204630 (sft-historical). This is described in the linked paper (see above).

Methods for processing the data: see the paper.

Instrument- or software-specific information needed to interpret the data: See https://doi.org/10.5281/zenodo.14204630

Standards and calibration information, if appropriate:  n/a

Environmental/experimental conditions: n/a

Describe any quality-assurance procedures performed on the data: see the paper

People involved with sample collection, processing, analysis and/or submission: see the paper


DATA-SPECIFIC INFORMATION FOR: rYYYYMMDD.HH_000N.unf
(all region files have same format)

Number of variables: 6

Number of cases/rows: n/a

Variable List: <list variable name(s), description(s), unit(s) and value labels as appropriate for each>
1. BR1 – radial magnetic field array (dims: ns x nph, units: Gauss), double precision.
2. PLAGE – array of Ca II K intensity (dims: ns x nph, units: normalised), double precision.
3. PREG – longitude of region centroid (units: degrees), double precision.
4. CR – carrington rotation number, 16-bit integer.
5. COMPLETE – flag of whether region is "complete" (i.e. has sufficient polarity information from sunspot measurements) or not, values 1 (meaning complete) or 0 (meaning incomplete), 8-bit integer.
6. POL_FRAC – fraction of pixels with polarity from sunspot measurements, double precision.

Missing data codes: NaN

Specialized formats or other abbreviations used: the format is Fortran binary file (to facilitate use in the SFT model – see https://doi.org/10.5281/zenodo.14204630).