FY 1978

Winter circulation and hydrography over the continental shelf of the northwest Gulf of Alaska

Schumacher, J.D., R. Sillcox, D. Dreves, and R.D. Muench

NOAA Tech. Report ERL 404-PMEL 31, NTIS: PB-296914/AS, 16 pp (1978)

During winter 1977 temperatures and salinity were measured in the shelf region east of Kodiak Island and in the Shelikof Strait. Two subsurface cores of warm, saline water were observed; one was coincident with the shelf break and one extended northwestward from the break into the Amatuli Trough. The temperatures characteristic of these cores indicated that they were nonlocal, advective features perhaps originating in the Alaska current and that they reflected a bifurcation of this flow upstream. Current records for Shelikof Strait showed a strong southwesterly flow with no reversals, which suggested a barotropic component driven by an axial pressure difference and resulting in hydraulic flow. The forcing by the Alaska Current was augmented at times by a weak westward baroclinic flow resulting from local freshwater input.