Extreme Space Weather Events Observed Through the Decades

Thursday, 18 December 2014: 9:07 AM
William F Denig, National Geophysical Data Center, Boulder, CO, United States
Well before satellite observations provided exquisite information regarding the variability of the space environment the research community had to rely on cruder techniques, by today’s standards, for monitoring the sun-earth system. These early techniques included published reports of aurora at low latitudes, signatures in daily magnetograms, ionospheric soundings, ground-based observations of the sun, and variations in the cosmic ray background. This talk will focus on extreme space weather events that have occurred during the last eighty years or so. We will first establish how we define an extreme geo-effective event by using the Ap-star magnetic classification scheme of Allen [see Allen and Wilkinson in Solar-Terrestrial Predictions-IV, 1992]. For the top ten events we will then present representative examples of datasets available at the time used by the scientific community to support their research objectives.