Phase IIIa-CCS: Latitudinal variation of upwelling, retention, nutrient supply and freshwater effects in the California Current System

Abstract

This proposal requests funding to: a) synthesize the moored current meter, shore-based HF radar, ship-based hydrographic, and remotely sensed data from the GLOBEC Northeast Pacific (NEP) Long-Term Observation Program (LTOP) and related programs into a coherent, best description of the mesoscale variability along the Pacific Northwest coast from 42 to 48N; and b) relate this physical variability to primary production, zooplankton distributions, and salmon year-class strength in the region. The long-term moorings will allow quantification of the relevant time scales from internal waves to the inter-annual; the satellite images of sea surface temperature and chlorophyll will show the spatial scales; and the HF surface fields will allow timeand space-varying statistics of the mesoscale currents and quasi-Lagrangian pathways to be assessed. The primary scientific objective will be to characterize the alongshelf variability in the upwelling, the nutrients it supplies to the photic zone for utilization by marine organisms, and the retention times of plankton. This variability is affected by the alongshore distribution of the wind stress and fresh water input, by the changes in the bottom topography and coastline orientation, and by pre-conditioning established by inter-annual variability and climate change.