A survey of dissolved barium in the estuaries of major Arctic rivers and adjacent seas

Abstract

Analyses for dissolved Ba have been performed on water samples obtained from the estuaries of major Arctic rivers and adjacent seas between 1993 and 1996. Complex behavior was observed in the mixing zones between fluvial and oceanic waters. In these areas, riverine dissolved Ba signals were altered by mixing with different shelf water masses and by non-conservative processes such as uptake in association with biological activity and desorption from suspended riverine particles. Despite this complexity, dissolved Ba concentrations [Ba d] measured in samples associated with the Mackenzie River (138–574 nmol L -1) were clearly much higher than those measured in samples associated with any of the Eurasian Arctic rivers (12–175 nmol L -1). While the [Ba d] signatures of Arctic rivers are subject to temporal and seasonal variability, such variability appears to be much smaller than the overall difference between [Ba d] in the Mackenzie River and Eurasian Arctic rivers. These results suggest that Ba can be used to distinguish between North American and Eurasian components of fluvial discharge to the Arctic and thus provide information not available from other oceanographic tracers currently in use.