Last century warming over the Canadian Atlantic shelves linked to weak
Atlantic Meridional Overturning Circulation
The Atlantic meridional overturning circulation (AMOC) is a key
component of the global climate system. Many models predict a weakening
or even a collapse of the AMOC under future climate change. Recent
studies suggested a 20th century weakening of the AMOC of unprecedented
amplitude ( 15%) over the last millennium. Here, we present δ18O of
benthic foraminifera in a sediment core from the Laurentian Channel and
demonstrate that the δ18O trend is linked to the strength of the AMOC.
In this 100-year record, the AMOC signal decrease steadily to reach its
minimum value in the late 1970’s. The weakest AMOC signal is constant
until 2000. We present a longer δ18O record of 1,500 years and highlight
the uniqueness of these high δ18O values over that period. Moreover, the
long record is also characterized by statistically heavier δ18O during
the Little Ice age suggesting a relatively weak AMOC.