We investigate the freshwater composition of the shelf
and slope of the Arctic Ocean north of the New Siberian
Islands using geochemical tracer data (δ¹⁸O, Ba, and PO₄*)
collected following the extreme summer of 2007. We find
that the anomalous wind patterns that partly explained the sea
ice minimum at this time also led to significant quantities of
Pacific-derived surface water in the westernmost part of the
Makarov Basin. We also find larger quantities of meteoric
water near Lomonosov Ridge than were found in 1995.
Dissolved barium is depleted in the upper layers in one region
of our study area, probably as a result of biological activity in
open waters. Increasingly ice-free conditions compromise
the quantitative use of barium as a tracer of river water in the
Arctic Ocean.Keywords: Arctic, dissolved barium, stable isotope
