Revisiting Trans-Arctic Maritime Navigability in 2011–2016 from the Perspective of Sea Ice Thickness

Xiangying Zhou,Qinghua Yang,Chao Min,Jack C Landy,Longjiang Mu,Yijun Yang

doi:10.3390/rs13142766

Abstract

Arctic navigation has become operational in recent decades with the decline in summer sea ice. To assess the navigability of trans-Arctic passages, combined model and satellite sea ice thickness (CMST) data covering both freezing seasons and melting seasons are integrated with the Arctic Transportation Accessibility Model (ATAM). The trans-Arctic navigation window and transit time are thereby obtained daily from modeled sea ice fields constrained by satellite observations. Our results indicate that the poorest navigability conditions for the maritime Arctic occurred in 2013 and 2014, particularly in the Northwest Passage (NWP) with sea ice blockage. The NWP has generally exhibited less favorable navigation conditions and shorter navigable windows than the Northern Sea Route (NSR). For instance, in 2013, Open Water (OW) vessels that can only safely resist ice with a thickness under 15 cm had navigation windows of 47 days along the NSR (45% shorter than the 2011–2016 mean) and only 13 days along the NWP (80% shorter than the 2011–2016 mean). The longest navigation windows were in 2011 and 2015, with lengths of 103 and 107 days, respectively. The minimum transit time occurred in 2012, when more northward routes were accessible, especially in the Laptev Sea and East Siberian Sea with the sea ice edge retreated. The longest navigation windows for Polar Class 6 (PC6) vessels with a resistance to ice thickness up to 120 cm reached more than 200 days. PC6 vessels cost less transit time and exhibit less fluctuation in their navigation windows compared with OW vessels because of their ice-breaking capability. Finally, we found that restricted navigation along the NSR in 2013 and 2014 was related to the shorter periods of navigable days in the East Siberian Sea and Vilkitskogo Strait, with local blockages of thick ice having a disproportionate impact on the total transit. Shorter than usual navigable windows in the Canadian Arctic Archipelago and Beaufort Sea shortened the windows for entire routes of the NWP in 2013 and 2014.

Highlights

combined model and satellite sea ice thickness (CMST) spanning from 2011 to 2016 is a reanalysis sea ice dataset, generated by a regional, coupled ice–ocean model based on the Massachusetts Institute of Technology general circulation model (MITgcm) with sea ice data assimilation [25]
With relatively lower sea ice cover along the Northern Sea Route (NSR) in 2011 and 2015, there was greater potential for Open Water (OW) vessels to sail along the NSR smoothly
The optimal trans-Arctic shipping routes (OASR) map (Figure 1b) shows higher accessibility for Polar Class 6 (PC6) vessels with a greater number of ideal routes and expanding geographic regions compared with OWs along both the NSR and Northwest Passage (NWP)

Summary

Introduction

The Arctic climate is changing rapidly and warming at more than twice the rate of lower latitudes, which is known as Arctic amplification [1,2]. Rising temperature in the Arctic is strongest on the sea surface and accompanied by sea ice melting [3]. Arctic sea ice extent (SIE) has had a steeply downward trend since the 1990s [4,5], and the ocean is likely to be seasonally ice-free by the mid-21st century [6,7,8]. Reduction of sea ice cover results in a shorter shipping distance bridging the Atlantic and the Pacific, and commercial ship sailing in the Arctic will become increasingly operational in the Remote Sens.

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Conclusion