The Zurich sunspot number and its variations for 1700-1957

Abstract

A compilation of the monthly and annual daily relative sunspot number is given for the years 1749 to 1957. Wolf's annual values are recompiled and given, back to 1700 from 1749. Tabular data include monthly, annual, and moving 11‐year means and totals. Times of cycle minima and maxima and appearances of first and last spots are indicated. Graphical presentations are given for the annual, 11‐ and 22‐year means, cycle means and cycle totals, and for some monthly and five‐monthly means. A check for continuation of a relationship of secular change to cycle length is made.

Tests of Sunspot Number Sequences: 1. Using Ionosonde Data

“…Because observers will have used different criteria to define both spots and spot groups (and even a given observer's criteria may have changed with time) and because observer acuity varies from observer to observer and with time, intercalibrations of data are required (e.g. Chernosky and Hagan, 1958). All long-term sunspot-number data sequences are therefore an observational composite: this is true of the much-used original Wolf/Zurich/International sunspot-number data sequence (version 1 of the International Sunspot Number, here termed R) as published by Solar Influences Data Analysis Center (SIDC, the solar physics research department of the Royal Observatory of Belgium) and hence of all sunspot series based on R with corrections for known or putative discontinuities, for example, the corrected sequence [R C ] suggested by .…”

Annual Reconstruction of the Solar Cycle from Atmospheric 14C Variations

“…Sunspot numbers for cycles -4 and -3 (Fig. 2) which are based on Wolf's calculations (Chernosky and Hagan 1958) exhibit a rapid, possibly overestimated, recovery from the Maunder minimum. This approximately 70-year period of near zero solar activity has been estimated as extending over 1645-1715(Eddy 1976, 1654-1714 on the 1 4 C record (Stuiver and Quay 1980) and 1645-99 (Schove 1983.…”

“…1 represent, on a comparative basis, the variation from minimum to maXimum, and separately from maximum to minimum, of the annual relative sunspot numbers in solar cycles -4 through to 21. They are essentially based on data obtained from the record of the yearly means of Zurich numbers over 1700-1957, given by Chernosky and Hagan (1958) Cubic spline interpolation was next employed, when necessary, to establish a set of ordinates over the interval (0, 1) at the scaled time values of 0·2, o . 4, 0·6 and 0·8.…”

Aerospace thermodynamic properties expected above Cape Kennedy for the 1966-1967 period.

“…Historical sunspot data show the following features: 1) the peaks of the 11-yr cycle have increased progressively from cycle 16 (beginning 1923) to the highest peak ever recorded in cycle 19; 2) with the peak of cycle 19 so far from the mean peak of cycles 8-18, it can be expected that cycles 20 and 21 will show decreasing peaks on the basis of the general rule that a natural phenomenon, once deviating extremely, tends to return toward its mean; 3) the 260-yr record of solar activity shows that an ordered sequence of four increasing peaks has not been exceeded; 4) peaks of decreasing magnitude ordinarily follow the maximum peaks; 5) the 78-yr cycle, which appears to exist in the length of the sunspot cycle according to some authors, 16 -17 would require decreasing peaks in the twentieth and twenty-first cycles (starting from the 1923 minimum); and 6) the quasi-centennial cycle, 18 which appears to be present in the sunspot curve with zero yearly mean sunspot numbers near 1710, 1810, and 1910, would also require decreasing peaks in the twentieth and twenty-first cycles and even in some subsequent ones. Hence, it is predicted that the peaks of the 11-yr cycles 20 and 21 will be less than that of cycle 19 and that the peak of cycle 21 will approximate the mean peak of cycles 8-18. The numerical values of the predicted 10.7-cm fluxes, which were obtained from a cumulative frequency analysis of the daily 10.7-cm fluxes grouped according to maximum, medium, and minimum solar activity phases of the 1947 to 1962 period, 19 are shown in Fig.…”