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 7-20 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 22-24 August 2003)
Temperature Salinity

The product package includes nowcast and forecast maps of temperature (oC) and salinity (PSU) with superimposed vectors of sub-tidal velocity at four depth levels: 0m, 10, 30m and 200m. These levels are: the surface (0m), within the mixed layer (10m), the middle of the thermocline (30m) and within the California Undercurrent (200m). In addition, there are vertical sections of temperature off-shore from Point Ano Nuevo, Monterey bay and Point Sur. 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.

For the period 22-24 August the wind forcing is predicted to become more upwelling favorable. In the simulation, we see a resumption of upwelling at both Points Ano Nuevo and Sur, especially below the surface layer. Monterey Bay resumes a large-scale cyclonic circulation, and the flow by Monterey Peninsula starts to resume a southward flow by 24 August.


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