GLOBEC-NEP: Topographic Control of Mesoscale Variability in the Gulf of Alaska
D. L. Musgrave and T. E. Whitledge (both at Oregon State University) and S. Pegau (Kachemak Bay Estuarine Research Reserve)

This proposal addresses studies of the physical and biological distributions and processes and their effect on juvenile salmon recruitment on the Gulf of Alaska shelf. The spatial scope of the study is from Montague Strait to west of the Chiswell Ridge. The overriding them of the proposal is that along-shelf and cross-shelf mesoscale structures are due to bathymetric control of the currents. Physical and biological oceanographic characteristics associated with the Alaska Coastal Current, its offshore excursions in the Seward Eddy and Seward Counter Eddy, the shelfbreak front, slope eddies and meanders and the deep flow. These features affect the transport and distribution of deep-water zooplankton that are alleged to be an important food source for juvenile salmon and may determine their survival. An undulating, underwater, towed vehicle (SeaSoar) will be used to continuously map salinity, temperature, depth (CTD), and biooptical parameters. Surface samples of the above (minus depth), nutrients, and chlorophyll fluorescence will be measured continuously using similar sensors. We will use an Acoustic Doppler Current Profiler (ADCP) to measure along- and cross-track velocities to 150 m. In May and July, 2003, we will conduct two to three synoptic surveys (5 days each) of cross-shelf transects spaced every 10 km alongshelf.

The broader impacts of this study include the training of two PhD students in multidisciplinary oceanography and a better understanding of the effects of oceanographic effects on salmon variability in the Gulf of Alaska.

This page was last updated on March 28, 2002.

Maintained by:
Hal Batchelder [hbatchelder@coas.oregonstate.edu
College of Oceanic & Atmospheric Sciences
Oregon State University
Corvallis, OR 97331-5503
phone: 541-737-4500; FAX 541-737-2064