Location: 46°N, 130°W
Approximate Water Depth: 2,600 m at Base
The moorings at PN3A are far from the continental shelf (>350 km) and hence this area represents an open-ocean or pelagic site in the continuum of observing scales represented in the OOI’s cabled system. Here, large-scale currents including the North Pacific Current, the subpolar gyre and the northern end of the California Current interact. These currents transport heat, salt, oxygen, and biota, all of which are crucial to the region’s ecosystem. However, their variability arises from forcing as varied as tides and wind (0.5–5 day timescales) to interannual (El Niño) to decadal (Pacific Decadal Oscillation) timescales.
Examples of relevant science questions represented in the OOI Science requirements include: 1) How, and how strongly do tidal currents break down into turbulence, and what are the feedbacks on the large scale current system? Internal tides are ubiquitous vertical motions formed by tidal currents flowing past bottom features such as Axial Seamount and the base of continental margins with steep topography. 2) What is the impact of long- and short-term forcing changes on the structure and transports of the largescale current system and what are their effects on the ecosystem? Together with the global mooring at Ocean Station Papa, these processes can be studied with observing platforms in the water column at these two sites.
Description of Infrastructure: