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SUMMARY:The Carrington event not observed in most ice core nitrate records
  - Prof. Eric Wolff FRS\, British Antarctic Survey
DTSTART:20120515T143000Z
DTEND:20120515T153000Z
UID:TALK37531@talks.cam.ac.uk
CONTACT:Dr. Ailsa Benton
DESCRIPTION:The Carrington Event of 1859 is considered to be among the lar
 gest space weather events of the last 150 years. We show that only one out
  of 14 well-resolved ice core\nrecords from Greenland and Antarctica has a
  nitrate  spike dated to 1859. No sharp spikes are observed in the Antarct
 ic cores studied here. In Greenland numerous spikes are observed in the 40
  years surrounding 1859\, but where other chemistry was measured\, all lar
 ge spikes have the unequivocal signal\, including co-located spikes in amm
 onium\, formate\, black carbon and vanillic acid\, of biomass burning plum
 es. It seems certain that most spikes in an earlier core\, including that 
 claimed for 1859\, are also due to biomass burning plumes\, and not to sol
 ar energetic particle (SEP) events. We conclude that an event as large as 
 the Carrington Event did not leave an observable\, widespread imprint in n
 itrate in polar ice. Nitrate spikes cannot be used to derive the\nstatisti
 cs of SEPs.\n
LOCATION:room 330B\, British Antarctic Survey\, High Cross\, Cambridge\, C
 B3 0ET
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