Abstract

Sunspot Cycle Minima and Pandemics: The Case for Vigilance?

Wickramasinghe NC, Edward J Steele, Wainwright M, Gensuke Tokoro, Manju Fernando and Jiangwen Qu

Direct records of sunspots and the solar cycle have been maintained in astronomical observatories for about 1610 AD, while indirect records derived from 14C analysis of ice cores go back to about 900 AD. Minima in the sunspot cycle present conditions conducive to the entry or activation of new pathogens and also for mutations of already circulating bacteria and viruses. Three grand minima of solar activity on record–the Sporer minimum (1450-1550 AD), Maunder minimum (1650-1700 AD) and the Dalton minimum (1800-1830) have all been marked by a preponderance of pandemics–Small Pox, English Sweats, Plague and Cholera. The sunspot numbers recorded for the present period 2002-2017 include the deepest sunspot minimum (Cycle 23-24) since records began, and a trend to declining numbers throughout the cycle. The same period has seen the resurgence of several pandemics– SARS, MERS, Zika, Ebola, Influenza A. We consider it prudent to take note of these facts whilst planning future strategies for pandemic surveillance and control.