It is illustrated by observations and model simulations, how monthly mean sea
surface temperature anomalies (SSTA) show enhanced variance at the annual period
in the extra tropics (an annual peak in the variance spectrum). A mechanism, related
to the re-emergence of winter SST anomalies, is proposed to explain the annual peak
in SST spectrum. The idea is supported by the analysis of a hierarchy of models,
including IPCC model simulations.
The results of the model experiments further suggest that the annual peak is weak
or not present if decadal SST variability is forced by local air-sea interaction. However,
if ocean subsurface temperature variability forces decadal SST variability, the annual
peak is much stronger. Strong annual peaks may therefore be seen as an indication for
ocean forced decadal SST variability in the extra-tropics.

Full Article: http://www.ifm-geomar.de/fileadmin/personal/fb1/me/ddommenget/paper/moeller.et.al.annual.peak.accepted.pdf

Last Updated: 2007-12-13