Low-frequency storminess signal at Bermuda linked to cooling events in the North Atlantic region Academic Article uri icon

abstract

  • AbstractNorth Atlantic climate archives provide evidence for increased storm activity during the Little Ice Age (150 to 600 calibrated years (cal years) B.P.) and centered at 1700 and 3000cal years B.P., typically in centennialscale sedimentary records. Meteorological (tropical versus extratropical storms) and climate forcings of this signal remain poorly understood, although variability in the North Atlantic Oscillation (NAO) or Atlantic Meridional Overturning Circulation (AMOC) are frequently hypothesized to be involved. Here we present records of late Holocene storminess and coastal temperature change from a Bermudian submarine cave that is hydrographically circulated with the coastal ocean. Thermal variability in the cave is documented by stable oxygen isotope values of cave benthic foraminifera, which document a close linkage between regional temperature change and NAO phasing during the late Holocene. However, erosion of terrestrial sediment into the submarine cave provides a storminess signal that correlates with higherlatitude storminess archives and broader North Atlantic cooling events. Understanding the driver of this storminess signal will require higherresolution storm records to disentangle the contribution of tropical versus extratropical cyclones and a better understanding of cyclone activity during hemispheric cooling periods. Most importantly, however, the signal in Bermuda appears more closely correlated with proxybased evidence for subtle AMOC reductions than NAO phasing.

published proceedings

  • PALEOCEANOGRAPHY

altmetric score

  • 12.294

author list (cited authors)

  • van Hengstum, P. J., Donnelly, J. P., Kingston, A. W., Williams, B. E., Scott, D. B., Reinhardt, E. G., Little, S. N., & Patterson, W. P.

citation count

  • 14

complete list of authors

  • van Hengstum, Peter J||Donnelly, Jeffrey P||Kingston, Andrew W||Williams, Bruce E||Scott, David B||Reinhardt, Eduard G||Little, Shawna N||Patterson, William P

publication date

  • February 2015