U.S. Dept. of Commerce / NOAA /
OAR / PMEL
New Ideas on Marine Productivity in the Gulf of Alaska: Results from
Models and Observations from the SALMON Project and GLOBEC
Dave Musgrave, University of Alaska, Fairbanks
Abstract
Our ideas have changed significantly about the mechanisms
of marine production on the shelf in the northern Gulf of Alaska. Dynamical
theory and observations originally focused on cross-shelf variation of
currents and oceanographic variables driven by freshwater runoff and wind-driven
downwelling. Observations from a variety of platforms now indicate that
along-shelf variation in properties is as great as the cross-shelf. Kate
Hedstrom at ARSC has been running the Regional Ocean Model System (ROMS)
in the Gulf of Alaska. The model results qualitatively agree with observations
. To the extent that the results are accurate, they show that variability
over short time scales (four to seven days) adds another form of complexity
to the currents on the shelf. The possibility of a new dimension of variability
(time) has profound implications for any observing or modeling program
that attempts to look at the spatial and temporal variability of the marine
productivity. This summer the
GLOBEC Mesoscale Survey
will test the model results using new sophisticated technologies for
rapid, highly resolved (spatially) measurements of sea surface temperature
(AVHRR
), surface currents
, in situ currents, and oceanographic variables.
