A Comparison of Arctic Ocean Sea Ice Export Between Nares Strait and the Canadian Arctic Archipelago

Abstract

The recent decline in the Arctic Ocean sea ice extent during the summer months (e.g., Parkinson & DiGirolamo, 2021) is one of the most visible features of a warmer Arctic. However, identifying the processes responsible for the Arctic's sea ice decline is challenging because ice is very dynamic and does not always melt locally. While a considerable amount of sea ice does melt locally in the Arctic Ocean (Babb et al., 2022;Kwok & Cunningham, 2010;Perovich et al., 2008), a large amount is also transported out of the Arctic Ocean to southern latitudes where it melts and delivers a considerable volume of freshwater to the global ocean (Kwok, 2004(Kwok, , 2009. The major passageways for southward Arctic Ocean ice export are Fram Strait, Nares Strait, the channels within the Canadian Arctic Archipelago (CAA), and the Bering Strait. There is inter-annual variability in Arctic Ocean ice export at these passageways but in general Fram Strait has historically provided the largest contribution with an average area ice export of 880 × 10 3 km 2 (Smedsrud et al., 2017). Arctic Ocean ice area export through Nares Strait and the CAA have been an order of magnitude lower than Fram Strait over the satellite observation era, with respective annual means between 42X10 3 km 2 and 87 × 10 km 2 (

The Stepwise Reduction of Multiyear Sea Ice Area in the Arctic Ocean Since 1980

“…Ice export through these channels is limited by the seasonal formation of ice arches (also known as ice bridges or barriers; Hibler et al, 2006;Kirillov et al, 2021;Melling, 2002) that impede ice motion, yet as the Arctic warms these arches are forming for shorter periods and occasionally not forming at all, allowing increased ice export (Howell et al, 2023;Howell & Brady, 2019;. Annual ice export into Nares Strait increased from 33,000 km 2 between 1996 and 2002 (Kwok, 2005) to 87,000 km 2 between 2019 and 2021 and more recently 95,000 km 2 between 2017 and 2021 (Howell et al, 2023). Meanwhile, annual ice export into the QEI increased from 8,000 km 2 between 1997 and 2002 (Kwok, 2006) to 25,000 km 2 between 1997 and 2018 (Howell & Brady, 2019), with a recent peak of 120,000 km 2 in 2020 (Howell et al, 2023).…”

“…For large channels like Fram Strait, and channels into the Kara and Barents Seas, F was calculated weekly using fields of sea ice drift and concentration from the NSIDC data sets Total ice export into the QEI has been quantified for the period from 1997 to 2002 (Kwok, 2006), 1997-2018(Howell & Brady, 2019, and more recently 2017-2021 (Howell et al, 2023). MYI flux was also determined during the latter period and revealed that MYI comprises 85% of the total ice flux into the QEI.…”

“…MYI can be exported across any of the open boundaries of the Arctic Ocean, though it is primarily exported through Fram Strait (87%; Kuang et al, 2022). A lesser amount is exported seasonally into Nares Strait (Howell et al, 2023;Kwok, 2005; and into the Queen Elizabeth Islands (QEI) of the CAA (Howell & Brady, 2019;Howell et al, 2023), while MYI has occasionally been exported into the Barents Sea (Kwok et al, 2005) and through the Bering Strait (Babb et al, 2013).…”

“…MYI export into Nares Strait and the QEI is an order of magnitude lower than MYI export through Fram Strait, yet export is increasing through both channels. This is particularly important because the oldest and thickest MYI in the Arctic is exported through these channels (Howell et al, 2023;Moore et al, 2019). Furthermore, increasing MYI export through these channels has implications for ships operating downstream along the Northwest Passage (Howell et al, 2022;Pizzolato et al, 2014) and as far south as Newfoundland (Barber et al, 2018).…”

“…Due to the limitations with quantifying MYI deformation, and the assumption that it is a relatively small term, we focus on the other three terms. To-date MYI export, replenishment, and melt have been examined in different works over different periods of time and for different regions (i.e., Babb et al, 2022;Howell et al, 2023;Kuang et al, 2022;Kwok, 2004bKwok, , 2007Kwok, , 2009Kwok & Cunningham, 2010;Ricker et al, 2018), yet they have not been coherently analyzed to produce a long-term MYI budget of the Arctic Ocean and examine MYI loss. Regan et al (2023) recently examined MYI area and volume loss from 2000 to 2018 in terms of MYI export, melt, replenishment, and ridging using the neXtSIM ice-ocean model, yet the model performs poorly during some years (i.e., 2016;Boutin et al, 2023) and is limited to an 18 year period at which point MYI had already declined considerably.…”