[1] A three-dimensional model of the California Current System (CCS) from 35°N to 48°N extending offshore to 134°W is coupled with a four-component trophic model. The model reproduces many conspicuous characteristics in the CCS, including: complex, filamentary, mesoscale surface features seen in the pigment and temperature from satellite imagery; wind-driven coastal upwelling at appropriate spatial and temporal scales; and the close correlation between prominent features seen in pigment and those in temperature observed by satellites (Abbott and Zion, 1985). Statistical estimates of the characteristic spatial scales of variability, as calculated from the coupled, nested model, agree with those previously estimated from satellite images (for both surface temperature and pigment Abbott, 1988, 1994)). Model estimates of the characteristic temporal scales of variability, from decorrelation times, agree with those previously estimated from satellite images. Typical model decorrelation times lie between 2 and 4 days, in agreement with calculations from earlier sequences of (Coastal Zone Color Scanner (CZCS) and advanced very high resolution radiometer (AVHRR)) satellite images Abbott, 1988, 1994).

A primitive equation ocean general circulation model is used to investigate climate impacts in the North Pacific Ocean in the 1996 to 2003 period. The objective is to assess the model ability to reproduce observed modes of variability and study their impact in the northeast Pacific. This work is done within the framework of the U.S. Global Ecosystem (GLOBEC) Northeast Pacific Program studying the links between climate variability and ecosystem dynamics. Three large‐scale events are considered: The 1997/1998 El Niño, the 1999 “regime shift,” and the 2002 cold/fresh subsurface anomalous water mass that was observed in the Gulf of Alaska and off the coast of Oregon. The circulation model is shown to generate the correct seasonal to interannual large‐scale variability and is able to represent the climatic signals of interest in the eastern Pacific. We show that the influence of the 1997/1998 El Niño reached the coastal Gulf of Alaska and induced an increase in the upper ocean heat content along the coast of North America. An analysis of the sea surface temperature for the model years shows agreement between model and data in the representation of the 1999 shift to a cold phase in the eastern and northern North Pacific. Finally, using the model results, we speculate that the origin of the 2002 cold/fresh anomaly in the northeast Pacific was due to enhanced mixing during the preceding winter in the center of the Alaska gyre. Owing to anomalous changes in the density structure of the upper ocean, this water was able to move geostrophically toward the coast and it persisted in the northeast Pacific below the mixed layer the following year.

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We used a 5 year time series of transport, temperature, and salinity from moorings at the head of Barrow Canyon to describe seasonal variations and construct a 37 year transport hindcast. The latter was developed from summer/winter regressions of transport against Bering‐Chukchi winds. Seasonally, the regressions differ due to baroclinicity, stratification, spatial, and seasonal variations in winds and/or the surface drag coefficients. The climatological annual cycle consists of summer downcanyon (positive and toward the Arctic Ocean) transport of ∼0.45 Sv of warm, freshwaters; fall (October–December) upcanyon transport of ∼−0.1 Sv of cooler, saltier waters; and negligible net winter (January–April) mass transport when shelf waters are saline and near‐freezing. Fall upcanyon transports may modulate shelf freezeup, and negligible winter transports could influence winter water properties. Transport variability is largest in fall and winter. Daily transport probability density functions are negatively skewed in all seasons and seasonal variations in kurtosis are a function of transport event durations. The latter may have consequences for shelf‐basin exchanges. The climatology implies that the Chukchi shelf circulation reorganizes annually: in summer ∼40% of the summer Bering Strait inflow leaves the shelf via Barrow Canyon, but from fall through winter all of it exits via the western Chukchi or Central Channel. We estimate a mean transport of ∼0.2 Sv; ∼50% less than estimates at the mouth of the canyon. Transport discrepancies may be due to inflows from the Beaufort shelf and the Chukchi shelfbreak, with the latter entering the western side of the canyon.