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

Robert Pickart, Woods Hole Oceanographic Institution

Abstract

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 24 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.