Abstract:
[Abstract]
For the purpose of detecting the effects of human activities on
climate change, it is important to document natural change in past
climate. In this context, it has proved particularly difficult to
study the variability in the occurrence of extreme climate events,
such as storms with exceptional rainfall. Previous investigations have
established storm
... chronologies using sediment cores from single lakes,
but such studies can be susceptible to local environmental bias. Here
we date terrigenous inwash layers in cores from 13 lakes, which show
that the frequency of storm-related floods in the northeastern United
States has varied in regular cycles during the past 13,000 years (13
kyr), with a characteristic period of about 3 kyr. Our data show four
peaks in storminess during the past 14 kyr, approximately 2.6, 5.8,
9.1 and 11.9 kyr ago. This pattern is consistent with long-term
changes in the average sign of the Arctic Oscillation, suggesting that
modulation of this dominant atmospheric mode may account for a
significant fraction of Holocene climate variability in North America
and Europe. 
