Synthesis of Physical Measurements from the Pacific Arctic Group: Flux of Pacific Water through Barrow Canyon, Chukchi Sea

Pacific water flowing northward through Bering Strait has profound impacts on the physical state
and ecosystem of the Western Arctic Ocean. The cold, dense water fluxed northward in winter
and spring ventilates the upper halocline and provides nutrients that fuel primary production and
impact the carbon cycle.The warm water penetrating northward in summer melts the seasonal ice
and is contributing to the decline of the perennial ice pack. As such, it is crucial that we
understand the pathways, modifications, and dynamics of the Pacific water as it penetrates the
Arctic domain. The six nations comprising the Pacific Arctic Group (PAG) have carried out
coordinated fieldwork, data sharing, and scientific analysis in the western Arctic for over a
decade. Since the establishment of the Distributed Biological Observatory (DBO) in 2010, ships
from these nations have been occupying a set of key transects in the Pacific Arctic domain on
cruises of opportunity. The DBO transect across Barrow Canyon, in the northeast Chukchi Sea,
has been occupied a total of 19 times with hydrographic measurements. This data set thus
provides a unique opportunity to investigate the circulation, water mass structure, and seasonal to
interannual variability at a key choke point where much of the Pacific water passes on its way to
the deep basin. Herein it is proposed to use the hydrographic/nutrient transects across Barrow
Canyon collected by the PAG group from 2010-12 to advance our understanding of the role of
the canyon in channeling and modifying the northward-flowing Pacific water.