Synoptic Maps of CaII K line intensity based on observations from MWO (1915-1985)

This dataset contains Carrington synoptic maps of Ca II 393.4 nm intensity for the years 1915-1985. These maps are produced using Mount Wilson Observatory calcium K-line images. The digitization and initial flat fielding was done by the solar group at UCLA as described in Lefebvre et al. 2005 (Mem. Soc. Astron. Ital., 76, 862) and in Bertello et al. 2010 (Sol. Phys., 264, 31). The current dataset is reprocessed in 2017-2018 at NSO by Luca Bertello: the full disk images were corrected for vignetting and intensity was normalized as described in Pevtsov et al. 2016 (A&A, 585, A40, doi: 10.1051/0004-6361/201526620. The details of the map-making procedure are described in the paper by Sheeley, Cooper, & Anderson 2011 (ApJ 730:51). Calculation of uncertainties is described by Bertello et al 2014 (Solar Phys., 289/7, 2419, doi: 10.1007/s11207-014-0480-3). Each fits file has three planes: Ca II K line intensity, map of uncertainties, and map of weights.