THE 100TH YEAR OF WOLF,RUDOLF DEATH - DO WE HAVE THE CORRECT RECONSTRUCTION OF SOLAR-ACTIVITY

Citation
Dv. Hoyt et al., THE 100TH YEAR OF WOLF,RUDOLF DEATH - DO WE HAVE THE CORRECT RECONSTRUCTION OF SOLAR-ACTIVITY, Geophysical research letters, 21(18), 1994, pp. 2067-2070
Citations number
9
Categorie Soggetti
Geosciences, Interdisciplinary
ISSN journal
00948276
Volume
21
Issue
18
Year of publication
1994
Pages
2067 - 2070
Database
ISI
SICI code
0094-8276(1994)21:18<2067:T1YOWD>2.0.ZU;2-1
Abstract
In the one hundred years since Wolf died, little effort has gone into research to see if improved reconstructions of sunspot numbers can be made. We have gathered more than 349,000 observations of daily sunspot group counts from more than 350 observers active from 1610 to 1993. B ased upon group counts alone, it is possible to make an objective and homogeneous reconstruction of sunspot numbers. From our study, it appe ars that the Sun has steadily increased in activity since 1700 with th e exception of a brief decrease in the Dalton Minimum (1795-1823). The significant results here are the greater depth of the Dalton Minimum, the generally lower activity throughout the 1700's, and the gradual r ise in activity from the Maunder Minimum to the present day. This sola r activity reconstruction is quite similar to those Wolf published bef ore 1868 rather than the revised Wolf reconstructions after 1873 which used geomagnetic fluctuations.