GLOBEC: Long-Term Observation Program in the Marine Ecosystem of the Northern California Current

Oregon State University, Corvallis OR

Investigators

Abstract

GLOBEC Long-Term Observation Program in the Marine Ecosystem of the Northern California Current The goal of the Long-Term Observation Program (LTOP) within GLOBEC North East Pacific Program is to provide the fundamental seasonal description of the physical, chemical and biological environment at a few critical locations; the LTOP also aims to provide information on interannual variability and long-term changes. The specific objectives of the LTOP in the Northern California Current region are: seasonal sampling (five times per year) of two-dimensional temperature, salinity, density, velocity, dissolved oxygen, nutrient, chlorophyll and zooplankton fields through September 2003; to determine whether the domains north and south of Cape Blanco have similar interannual variability; and to determine whether the 1976 - 1977 regime shift in the large-scale climate is reflected in significant differences between contemporary (1997 - 2003) and historical (1961 - 1973) observations of the marine ecosystem off central Oregon. The PIs will sample three cross-margin transects in spring and summer to compare the upwelling regimes north and south of Cape Blanco and to estimate the large-scale alongshore gradients between 40 degrees N and 45 degrees N; only one transect will be sampled during the downwelling season (late fall and winter) when there is high alongshore homogeneity. Sampling will be enhanced during the two years (2000 and 2002) of GLOBEC Process Studies in the California Current by adding two intermediate cross-shelf sections on spring and summer cruises in those years. Sampling on all lines will include underway sampling as well as on-station sampling of the water column. WOCE-type drifters drogued at 15 m will be deployed at five locations off Newport on all spring and summer cruises. One mooring will be maintained off Newport to provide a continuous record of the temporal variability of the marine ecosystem that can be used to identify more precisely the timing of the spring and fall transitions, the onset of anomalous conditions associated with El Nino episodes, and the coastal ocean response to local wind forcing.