S. J. Bograd, R. Mendelssohn, F. B. Schwing and A. J. Miller,
Spatial heterogeneity of sea surface temperature trends in the Gulf of Alaska.
Atmosphere-Ocean, 43, 241-247.
State-space models were used to derive nonparametric sea
surface temperature (SST) trends from 26 locations in
and around the Gulf of Alaska for the period 1950-97.
The SST trends reflect important large-scale climate impacts
associated with El Nino events and regime shifts.
But they also reveal significant spatial heterogeneity across
the region. The SST trends cluster into five distinct regions
that define a robust zonal and meridional asymmetry. The
meridional differences reflect the relative impact of El
Nino events, while the zonal differences reflect variations
in the timing and amplitude of a region-wide post-1970
warming trend. The 1976 regime shift is evident primarily as an
accelerated warming in the northern and eastern portions of
the Gulf of Alaska. The climate signals identified in
the SST series are of sufficient magnitude and duration to
potentially foster changes in lower trophic productivity and structure,
which could lead to a broader ecosystem
reorganization. Regional differences in Steller
sea lion population trends may have resulted from
a spatially heterogeneous upper-ocean response to large-scale climate variability.