Wind-driven transport pathways for Eurasian Arctic river discharge

Distributions of temperature, salinity, and barium in near-surface waters ( depth less than or equal to 50 m) of the Laptev Sea and adjacent areas of t he Arctic Ocean are presented for the summers of 1993, 1995, and 1996. The tracer data indicate that while fluvial discharge was largely confined to t he shelf region bf the Laptev Sea in the summer of 1993, surface waters con taining a significant fluvial component extended beyond the shelf break and over the slope and basin areas north of the Laptev Sea in the summers of 1 995 and 1996. These distributions of fluvial discharge are consistent with local winds and suggest two principal pathways by which river waters can en ter the central Arctic basins from the Laptev Sea. When southerly to southe asterly wind conditions prevail, river waters are transported northward bey ond the shelf break and over the slope and adjacent basin areas. These wate rs can then enter the interior Arctic Ocean via upper layer flow in the vic inity of the Lomonosov Ridge. Under other wind conditions, river waters are steered primarily along the inner Laptev shelf and into the East Siberian Sea as part of the predominantly eastward coastal current system. These wat ers then appear to cross the shelf and enter the interior Arctic Ocean via upper layer flow aligned roughly along the Mendeleyev Ridge. The extent to which either pathway is favored in a given year is largely determined by lo cal wind patterns during the summer months, when fluvial discharge is great est and shelf waters are at the lowest salinity of their annual cycle.