An Examination of the Non-Formation of the North Water Polynya Ice Arch

Ron F Vincent

doi:10.3390/rs12172712

Abstract

The North Water (NOW), situated between Ellesmere Island and Greenland in northern Baffin Bay, is the largest recurring polynya in the Canadian Arctic. Historically, the northern border of the NOW is defined by an ice arch that forms annually in Kane Basin, which is part of the Nares Strait system. In 2007 the NOW ice arch failed to consolidate for the first time since observations began in the 1950s. The non-formation of the NOW ice arch occurred again in 2009, 2010, 2017 and 2019. Satellite Advanced Very High Resolution Radiometry data shows that large floes broke off from the normally stable landfast ice in Kane Basin for each of these years, impeding ice arch formation. A closer analysis of a 2019 event, in which 2500 km2 of ice sheared away from Kane Basin, indicates that significant tidal forces played a role. The evidence suggests that thinning ice from a warming climate combined with large amplitude tides is a key factor in the changing ice dynamics of the NOW region. The non-formation of the NOW ice arch results in an increased loss of multiyear ice through Nares Strait.

Highlights

A polynya is an area of the polar ocean that remains relatively ice-free in climatic conditions that would normally result in thick ice cover
This paper examines the non-formation of the ice arch using satellite data in the optical and thermal infrared (TIR) regime
The ice arch in Kane Basin has failed to consolidate in five seasons (2007, 2009, 2010, 2017, 2019), a phenomenon that had not been observed prior to 2007 dating back to ice reconnaissance flights in the 1950s

Summary

Introduction

A polynya is an area of the polar ocean that remains relatively ice-free in climatic conditions that would normally result in thick ice cover These anomalous areas, which significantly impact the biology, climate, and oceanography of a region, are broadly categorized as sensible or latent heat polynyas. Polynyas have an ocean-to-atmosphere heat flux approximately two orders of magnitude greater than the surrounding ice pack and dominate the regional heat budget [1]. These high latitude oases are centers of considerable biodiversity and provide important habitats for marine mammals and birds [2]

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