AOSN-II August 2003

General simulation description

Data collected by the research vessel Point Sur and WHOI and Scripps gliders from 2-6 August 2003 were analyzed to provide an estimate for the synoptic conditions at that time. This estimate of synoptic conditions provided the initialization conditions for the Harvard Ocean Prediction System (HOPS) model simulations. Subsequently, each simulation has been restarted from the simulation which preceeded it.

Additional data from 7-19 August from Woods Hole Oceanographic Institution and Scripps Institute of Oceanography autonomous underwater vehicles (gliders) have been assimilated into the ongoing simulation. In addition, SST from a Naval Postgraduate School aircraft flight has been assimilated on 15 August. The complete data coverage during the exercise through 14 August is shown for the Scripps and the WHOI gliders.


Model Simulation Results (0000 UTC 20-22 August 2003)
[Monterey Bay Zoom]
Temperature Salinity

The product package includes nowcast and forecast maps of temperature (oC) and salinity (PSU) with superimposed vectors of sub-tidal velocity at three depth levels: 0m, 10 and 30m. These levels are: the surface (0m), within the mixed layer (10m), and the middle of the thermocline (30m). All products are for 0000Z of the respective day. Clicking on "Temperature" or "Salinity" in the table above accesses the products for that variable.


Simulation analysis

Atmospheric forcing for the PE model is derived from the US Navy operational COAMPS (Jim Doyle) at 3km resolution. Early August winds were generally not upwelling favorable. Winds were light and variable, leading to relaxation conditions. During the relaxation conditions, upwelling along the coast diminished and warm off-shore water moved on-shore. From 7 August through 19 August winds were upwelling favorable. The anomalous warming of Monterey Bay was replaced by cooler waters and significantly upwelling off Points Ano Nuevo and Sur occurred. The upwelled water was transported southwards across the mouth of Monterey Bay.

In this simulation, a general warming takes place due to reduced winds and upwelling at both Points Ano Nuevo and Sur appear to be significantly reduced or essentially stop. Circulation in Monterey Bay remains cyclonic but the "across-the-mouth" circulation moves both on-shore and has an increasing towards-shore component. The significant southward velocities near Point Sur have been reduced. The excessive warming on forecast day 2 (22 August) at the surface and 10m has been determined to be as a result of the input model forcing conditions ending prior to 22 August and inappropriate heating being persisted in the simulation.


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