Bond event

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Temperature proxies from ice cores. Dansgaard-Oeschger events are seen during the last glacial; only the Younger Dryas and 8.2 kyr Bond events show.
Temperature proxies from ice cores. Dansgaard-Oeschger events are seen during the last glacial; only the Younger Dryas and 8.2 kyr Bond events show.

Bond events are North Atlantic climate fluctuations occurring every ≈1470 years throughout the Holocene. Eight such events have been identified. Bond events may be the interglacial relatives of the glacial Dansgaard-Oeschger events.

The theory of 1500-year climate cycles in the Holocene was postulated by Gerard C. Bond of the Lamont-Doherty Earth Observatory at Columbia University, mainly based on petrologic tracers of drift ice in the North Atlantic.[1][2]

The existence of climatic changes, possibly on a quasi-1500 year cycle, is well established for the last glacial period from ice cores. Less well established is the continuation of these cycles into the holocene. Bond et al. (1997) argue for a climate cyclicity close to 1470 ± 500 years in the North Atlantic region. In their view, many if not most of the Dansgaard-Oeschger events of the last ice age, conform to a 1500-year pattern, as do some climate events of later eras, like the Little Ice Age, the 8.2 kiloyear event, and the start of the Younger Dryas. Later proponents of this view include S. Fred Singer of the University of Virginia and Dennis Avery of the Hudson Institute.[3]

The North Atlantic ice-rafting events happen to correlate with most weak events of the Asian monsoon over the past 9000 years,[4][5] as well as with most aridification events in the Middle East.[6] Also, there is widespread evidence that a ≈1500 yr climate oscillation caused changes in vegetation communities across all of North America.[7]

For reasons that are unclear, the only Holocene Bond event that has a clear temperature signal in the Greenland ice cores is the 8.2 kyr event.[citation needed]

The hypothesis holds that the 1500-year cycle displays nonlinear behavior and stochastic resonance; not every instance of the pattern is a significant climate event, though some rise to major prominence in environmental history.[8] Causes and determining factors of the cycle are under study; researchers have focused attention on patterns of tides, variations in solar output, and "reorganizations of atmospheric circulation."[8]

[edit] List of Bond events

Most Bond events do not have a clear climate signal; some correspond to periods of cooling, others are coincident with aridification in some regions.

  • ≈1,400 BP (Bond event 1) — roughly correlates with the Migration Period Pessimum (450–900 AD)
  • ≈2,800 BP (Bond event 2) — roughly correlates with the Iron Age Cold Epoch (900–300 BC)
  • ≈4,200 BP (Bond event 3) — correlates with the 4.2 kiloyear event
  • ≈5,900 BP (Bond event 4) — correlates with the 5.9 kiloyear event
  • ≈8,100 BP (Bond event 5) — correlates with the 8.2 kiloyear event
  • ≈9,400 BP (Bond event 6) — correlates with the Erdalen event of glacier activity in Norway,[9] as well as with a cold event in China.[10]
  • ≈10,300 BP (Bond event 7) — unnamed event
  • ≈11,100 BP (Bond event 8) — coincides with the transition from the Younger Dryas to the Boreal

[edit] References

  1. ^ Bond, G.; et al. (1997). "A Pervasive Millennial-Scale Cycle in North Atlantic Holocene and Glacial Climates". Science 278 (5341): 1257-1266. doi:10.1126/science.278.5341.1257. 
  2. ^ Bond, G.; et al. (2001). "Persistent Solar Influence on North Atlantic Climate During the Holocene". Science 294 (5549): 2130-2136. doi:10.1126/science.1065680. 
  3. ^ Avery, Dennis T.; Singer, S. Fred (2006). Unstoppable Global Warming: Every 1500 Years. New York: Rowman & Littlefield. ISBN 9780742551176. 
  4. ^ Gupta, Anil K.; Anderson, David M.; Overpeck, Jonathan T. (2003). "Abrupt changes in the Asian southwest monsoon during the Holocene and their links to the North Atlantic Ocean". Nature 421 (6921): 354–357. doi:10.1038/nature01340. 
  5. ^ Yongjin Wang; et al. (2005). "The Holocene Asian Monsoon: Links to Solar Changes and North Atlantic Climate". Science 308 (5723): 854-857. doi:10.1126/science.1106296. 
  6. ^ Parker, Adrian G.; et al. (2006). "A record of Holocene climate change from lake geochemical analyses in southeastern Arabia". Quaternary Research 66 (3): 465–476. doi:10.1016/j.yqres.2006.07.001. 
  7. ^ Viau, André E.; et al. (2002). "Widespread evidence of 1500 yr climate variability in North America during the past 14 000 yr". Geology 30 (5): 455–458. doi:10.1130/0091-7613(2002)030<0455:WEOYCV>2.0.CO;2. 
  8. ^ a b Cox, John D. (2005). Climate Crash: Abrupt Climate Change and What It Means for Our Future. Washington DC: Joseph Henry Press, 150-155. ISBN 0309093120. 
  9. ^ Dahl, Svein Olaf; et al. (2002). "Timing, equilibrium-line altitudes and climatic implications of two early-Holocene glacier readvances during the Erdalen Event at Jostedalsbreen, western Norway". The Holocene 12 (1): 17–25. doi:10.1191/0959683602hl516rp. 
  10. ^ Zhou Jing; Wang Sumin; Yang Guishan; Xiao Haifeng (2007). "Younger Dryas Event and Cold Events in Early-Mid Holocene: Record from the sediment of Erhai Lake". Advances in Climate Change Research 3 (Suppl.): 1673–1719. 


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