Oceanographic and atmospheric conditions on the continental shelf north of the Monterey Bay during August 2006

Authors

Steven R. Ramp, Soliton Ocean Services, Inc.Follow
Pierre F.J. Lermusiaux, Massachusetts Institute of TechnologyFollow
Igor Shulman, Stennis Space CenterFollow
Yi Chao, California Institute of Technology
Rebecca E. Wolf, Naval Postgraduate School
Frederick L. Bahr, Monterey Bay Aquarium Research InstituteFollow

Date of this Version

2011

Citation

Dynamics of Atmospheres and Oceans 52 (2011) 192– 223; doi:10.1016/j.dynatmoce.2011.04.005

Abstract

A comprehensive data set from the ocean and atmosphere was obtained just north of the Monterey Bay as part of the Monterey Bay 2006 (MB06) field experiment. The wind stress, heat fluxes, and sea surface temperature were sampled by the Naval Postgraduate School’s TWIN OTTER research aircraft. In situ data were collected using ships, moorings, gliders and AUVs. Four data-assimilating numerical models were additionally run, including the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS®) model for the atmosphere and the Harvard Ocean Prediction System (HOPS), the Regional Ocean Modeling System (ROMS), and the Navy Coastal Ocean Model (NCOM) for the ocean.

The scientific focus of the Adaptive Sampling and Prediction Experiment (ASAP) was on the upwelling/relaxation cycle and the resulting three-dimensional coastal circulation near a coastal promontory, in this case Point Año Nuevo, CA. The emphasis of this study is on the circulation over the continental shelf as estimated from the wind forcing, two ADCP moorings, and model outputs. The wind stress during August 2006 consisted of 3–10 day upwelling favorable events separated by brief 1–3 day relaxations. During the first two weeks there was some correlation between local winds and currents and the three models’ capability to reproduce the events. During the last two weeks, largely equator-ward surface wind stress forced the sea surface and barotropic poleward flow occurred over the shelf, reducing model skill at predicting the circulation. The poleward flow was apparently remotely forced by mesoscale eddies and alongshore pressure gradients, which were not well simulated by the models. The small, high-resolution model domains were highly reliant on correct open boundary conditions to drive these larger-scale poleward flows. Multiply-nested models were no more effective than well-initialized local models in this respect.