Growth increments of coralline red alga Clathromorphum compactum capture
sea-ice variability links to Atlantic Multidecadal and Arctic
Oscillations (1805 - 2015)
Abstract
The Atlantic Multidecadal Oscillation (AMO), Arctic Oscillation (AO),
and related North Atlantic Oscillation (NAO) have been linked to
multidecadal, decadal, and/or interannual sea-ice variability in the
arctic, but their relative influences are still under evaluation. While
instrumental AMO and reliable AO records are available since the
mid-1800s and 1958, respectively, satellite sea-ice concentration
datasets start only in 1979, limiting the shared timespan to study their
interplay. Growth increments of the coralline algae, Clathromorphum
compactum, can provide sea-ice proxy information for years prior to
1979. We present a seasonal 210-year algal record from Lancaster Sound
in the Canadian Arctic Archipelago capturing low frequency AMO
variability and high frequency interannual AO/NAO prior to 2000. We
suggest that sea-ice variability here is strongly coupled to these
large-scale climate processes, and that sea-ice cover was greater and
the AO more negative in the early and late 19th century compared to the
20th.