Gangopadhyay, Avijit
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Abstract In this project, our goal is to probe the connections between Calanus finmarchicus distributions and the physical oceanographic properties, climate variability, and basin-scale circulation changes that are likely to affect the copepod's transport onto Georges Bank. We will do this using a combination of numerical model simulations and observational data. Our initial focus is on completing the basin-scale simulations for the North Atlantic, which was started as part of an ongoing NASA-IDS project. We presented the initial results from the NASA project first. A major development in our current NASA-funded work is the systematic computation of a heat flux product for the low-NAO period (1958-1971). The NCEP reanalysis product was shown to be overestimating the heat loss in the high latitude regions by Josey, 2001 and by Visbeck et al., 2003. Comparison of the NCEP reanalysis during 1980-1993 with the Southampton Oceanographic Center's (SOC) product during the same period resulted in a regression model for the high NAO period. These regression model coefficients were then used to calibrate the low-NAO period NCEP data to generate realistic low-NAO heat flux climatology. To the best of our knowledge, this product is unique and will be very valuable for forcing our eddy-resolving simulations. Preliminary results with these new fields are encouraging with realistic Gulf Stream and eddy activities. It is expected that these simulations for 1990s will be completed by December, 2006. High resolution field generation via multi-scale synthesis of GOMGB feature model derived synthetic profiles (FORMS, Gangopadhyay et al., 2003) and basin-scale simulated fields (from ROMS) for the GLOBEC years will then begin. An example of this synthesis methodology was presented. Our proposed biological simulations will then utilize the high-resolution fields with individual-based models to investigate the Lagrangian pathways for zooplankton behavior in different climatic conditions. The biological IBM simulations will be analyzed for understanding impact of climate and BSV on calfin seeding and production. |