Active region dipole moments determined from NSO carrington maps

Citation and Acknowledgements Please cite both this database the paper describing it, as well as adding the following acknowledgement: "Active region dipole moments determined from NSO synoptic carrington maps were downloaded from the solar dynamo dataverse (https://dataverse.harvard.edu/dataverse/solardynamo), maintained by Andrés Muñoz-Jaramillo." Database citation format is shown at the top of this page, underneath the database title. It can be downloaded in a variety of formats directly from this page The paper describing this database is T. Whitbread, A.R. Yeates and A. Muñoz-Jaramillo, How many active regions are necessary to predict to solar dipole moment?, The Astrophysical Journal 863, 116, (2018). https://ui.adsabs.harvard.edu/abs/2018ApJ...863..116W/abstract Description Database of magnetic active region properties extracted from NSO synoptic carrington maps of the Sun's photospheric line-of-sight magnetic flux between carrington rotations CR 1641 and CR 2196 inclusive. Regions need not be bipolar, but rather can have complex, multipolar structures. The data were first used in Whitbread et al. (2018). The plot below summarizes the dataset, showing latitude versus time, coloured by axial dipole moment (saturated at 25% of maximum): Separate files are provided for each solar cycle, defined purely by date. The start dates used for each cycle are 1976-May-1, 1986-Mar-10, 1996-June-1 and 2008-Aug-03. In each file, the columns are as follows: Carrington rotation number. Carrington longitude of region centre [degrees]. Latitude of region centre [degrees]. Total magnetic flux of each polarity [Maxwells]. Axial dipole moment at time of observation [Gauss]. Important: The latitude and longitude denote the centroid of unsigned magnetic flux. Regions are not assumed to be bipolar, so tilt angle does not make sense as a measure. The more meaningful physical measure is axial dipole moment. The original carrington maps were downloaded from the NSO website: http://solis.nso.edu/0/vsm/vsm_maps.php. Before cr2007, data from the KPVT (868.8nm line) were used, and from cr2007 onwards we used data from SOLIS/VSM (630.2nm, line-of-sight magnetic flux, 360x180 resolution). The active regions and their properties were identified from the sequence of carrington maps using an automated procedure, as in the sft_data code (available at https://github.com/antyeates1983/sft_data). In this code, each region is defined as a connected area of strong magnetic flux, and is corrected for flux imbalance. Here we used the parameters sigma=3 and Bpar=39.8G. The properties given in this dataset were calculated at the time of observation of the region, before any further evolution. Main Limitations The main limitations of these data are: Sometimes, nearby active regions are classified as a single region by the automated method, and hence assigned an overall flux and dipole moment. Some regions are strong enough to be detected more than once in consecutive carrington rotations. In such cases, there is a separate entry in the database for each carrington rotation (i.e. there is no tracking of regions over time). Observational gaps in the original NSO synoptic maps mean that some regions are likely missing.