US-GLOBEC: NWA Georges Bank: :Impacts of Climate and Basin-Scale Variability on Seeding and Production of Calanus finmarchicus in the Gulf of Maine/Georges Bank Region

University Of Massachusetts, Dartmouth, North Dartmouth MA

Investigators

Abstract

The processes linking the ecosystems of Georges Bank, Scotian Shelf, Slope Sea and Gulf of Main to climate variability-induced, basin-scale circulation changes caused by large-scale atmospheric effects such as the North Atlantic Oscillation (NAO) appear to occur over both multi-decadal and interannual time scales. This project aims to elucidate how these multi-year changes in circulation within the western North Atlantic basin affect C. finmarchicus, specifically its transport onto Georges Bank. This will be accomplished via a combination of numerical model simulations and observational data. Primary tasks include: (1) Setting up and running an individual based model (IBM) for the Northwest Atlantic, using physical fields corresponding to the high-NAO (1980-1993) and low-NAO (1962-1971) periods obtained from an ongoing eddy-resolving North Atlantic simulation to understand multidecadal variability of Calanus finmarchicus seeding and production in this region; (2) Performing eddy-resolving basin-scale model simulations during 1988-1999 starting from already existing high-NAO simulations (from an ongoing NASA project) and run the IBM to study the interannual variability of C. finmarchicus seeding and production in this region; (3) Analyzing long-term in-situ physical and biological datasets and satellite-derived sea surface temperature (SST) along with in-situ physical, biological, and chemical data collected during the GLOBEC core-measurement period (1995-1999) to validate the basin-scale physical and biological fields and develop a broader understanding of C. finmarchicus seeding and production; (4) Generating four-dimensional high-resolution (5-km) physical fields using basin-scale fields and available data during 1993-1999, and running a series of IBM simulations at higher resolution in order to address questions relating ecosystem variability in the study regions to the large-scale fluctuations of the NAO. Within the GLOBEC synthesis effort, this study will enhance the scientific understanding of large-scale climatic and basin-scale forcing on the regional ecosystem of the NWA/GB region. Two graduate students will be trained. Results will be disseminated in scientific publications and presentations at national conferences while model output and several value-added fields will be made available via a website linked to the GLOBEC Georges Bank website.