Based on hydrographic data collected since 1955, Mediterranean outflow waters present in the eastern North Atlantic show a density compensated increase in both temperature and salinity. With an increase in temperature of 0.101 ± 0.024°C/decade and an increase in salinity of 0.0283 ± 0.0067 psu/decade in the Mediterranean outflow waters, the heat content gain from 1955 to 1993 is calculated to be 2.02 ± 0.31 × 106 J/m3, which surpasses the average gain in heat content of the North Atlantic basin over the latter half of the 20th century. This suggests that the Mediterranean outflow waters are an important contributor to climatological changes at intermediate depths within the mid‐latitude North Atlantic.

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.

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