Multi‐year sea‐ice conditions in the western Canadian arctic archipelago region of the northwest passage: 1968–2006

2008 ◽  
Vol 46 (2) ◽  
pp. 229-242 ◽  
Author(s):  
Stephen E.L. Howell ◽  
Adrienne Tivy ◽  
John J. Yackel ◽  
Steve McCourt
2006 ◽  
Vol 44 ◽  
pp. 329-338 ◽  
Author(s):  
Bea Alt ◽  
Katherine Wilson ◽  
Tom Carrières

AbstractThis case Study attempts to quantify the amount and timing of the import, export and through-flow of old ice in the Peary Channel–sverdrup Channel area of the northern Canadian Arctic Archipelago during the period 1998–2005. The Study combines quantitative weekly area-averaged ice coverage evaluations from the Canadian Ice Service (CIS) Digital Archive with detailed analysis of Radarsat imagery and ice-motion results from the CIS ice-motion algorithm. The results Show that in 1998 more than 70% of the old ice in Peary–sverdrup was lost, half by melt and export to the South and the other half by export north into the Arctic Ocean, and that no Arctic Ocean old ice was imported into Peary–sverdrup. A net import of 10% old ice was Seen in 1999, with Some indication of through-flow into Southern channels. In 2000, no net import of old ice occurred in Peary–sverdrup, but there was Significant through-flow, with evidence of old ice reaching the Northwest Passage by November. Full recovery of the old-ice regime was complete by the end of 2001. More than two-thirds of the recovery was due to the in Situ formation of Second-year ice. Conditions in the following 3 years were near normal.


2013 ◽  
Vol 7 (2) ◽  
pp. 1313-1358 ◽  
Author(s):  
S. E. L. Howell ◽  
T. Wohlleben ◽  
A. Komarov ◽  
L. Pizzolato ◽  
C. Derksen

Abstract. Record low mean September sea ice area in the Canadian Arctic Archipelago (CAA) was observed in 2011 (146 × 103 km2), a level that was nearly exceeded in 2012 (150 × 103 km2). These values eclipsed previous September records set in 1998 (200 × 103 km2) and 2007 (220 × 103 km2) and are ∼60% lower than the 1981–2010 mean September climatology. In this study, the driving processes contributing to the extreme light years of 2011 and 2012 were investigated, compared to previous extreme minima of 1998 and 2007, and contrasted against historic summer seasons with above average September ice area. The 2011 minimum was driven by positive July surface air temperature (SAT) anomalies that facilitated rapid melt, coupled with atmospheric circulation in July and August that restricted multi-year ice (MYI) inflow from the Arctic Ocean into the CAA. The 2012 minimum was also driven by positive July SAT anomalies (with coincident rapid melt) but further ice decline was temporarily mitigated by atmospheric circulation in August and September which drove Arctic Ocean MYI inflow into the CAA. Atmospheric circulation was comparable between 2011 and 1998 (impeding Arctic Ocean MYI inflow) and 2012 and 2007 (inducing Arctic Ocean MYI inflow). However, evidence of both preconditioned thinner Arctic Ocean MYI flowing into CAA and maximum landfast first-year ice (FYI) thickness within the CAA was more apparent leading up to 2011 and 2012 than 1998 and 2007. The rapid melt process in 2011 and 2012 was more intense than observed in 1998 and 2007 because of the thinner ice cover being more susceptible to positive SAT forcing. The thinner sea ice cover within the CAA in recent years has also helped counteract the processes that facilitate extreme heavy ice years. The recent extreme light years within the CAA are associated with a longer navigation season within the Northwest Passage.


2018 ◽  
Author(s):  
Bindu Panikkar ◽  
Benjamin Lemmond ◽  
Brent Else ◽  
Maribeth Murray

Sea ice throughout the Arctic is undergoing profound and rapid change. While ice conditions in the Canadian Arctic Archipelago have historically been more stable than conditions in the open ocean, a growing body of evidence indicates that the major thoroughfares in much of the western and central Canadian Arctic, including the Northwest Passage, are increasingly vulnerable to climatic forcing events. This is confirmed by the observations of Inuit elders and experienced hunters in the communities of Cambridge Bay, a hamlet along Dease Strait, and Kugluktuk, a hamlet situated at the mouth of the Coppermine River where it meets Coronation Gulf. People in these hamlets now face new navigational challenges due to sea-ice change. Navigation practices described by elders and hunters reflect an intimate knowledge of the land and ice topography, currents, and weather conditions for hundreds of kilometers around their communities, although people reported increasing unpredictable weather and ice conditions, making travel more treacherous. Many emphasized the importance of traditional knowledge and survival skills as necessary to adapt to ongoing and impending changes. They expressed particular concern that younger generations are untrained in traditional navigation practices, landscape- and weather-reading abilities, and survival practices. However, elders and hunters also stressed the need for more localized weather information derived from weather stations to help with navigation, as current weather and ice conditions are unprecedented in their lifetimes.


2013 ◽  
Vol 7 (6) ◽  
pp. 1753-1768 ◽  
Author(s):  
S. E. L. Howell ◽  
T. Wohlleben ◽  
A. Komarov ◽  
L. Pizzolato ◽  
C. Derksen

Abstract. Remarkably low mean September sea ice area in the Canadian Arctic Archipelago (CAA) was observed in 2011 (146 × 103 km2), a record-breaking level that was nearly exceeded in 2012 (150 × 103 km2). These values were lower than previous September records set in 1998 (200 × 103 km2) and 2007 (220 × 103 km2), and are ∼60% lower than the 1981–2010 mean September climatology. In this study, the processes contributing to the extreme light years of 2011 and 2012 were investigated, compared to previous extreme minima of 1998 and 2007, and contrasted against historic summer seasons with above average September ice area. The 2011 minimum was associated with positive June through September (JJAS) surface air temperature (SAT) and net solar radiation (K*) anomalies that facilitated rapid melt, coupled with atmospheric circulation that restricted multi-year ice (MYI) inflow from the Arctic Ocean into the CAA. The 2012 minimum was also associated with positive JJAS SAT and K* anomalies with coincident rapid melt, but further ice decline was temporarily mitigated by atmospheric circulation which drove Arctic Ocean MYI inflow into the CAA. Atmospheric circulation was comparable between 2011 and 1998 (impeding Arctic Ocean MYI inflow) and 2012 and 2007 (inducing Arctic Ocean MYI inflow). However, preconditioning was more apparent leading up to 2011 and 2012 than 1998 and 2007. The rapid melt process in 2011 and 2012 was more intense than observed in 1998 and 2007 because of the thinner ice cover being more susceptible to anomalous thermodynamic forcing. The thinner sea ice cover within the CAA in recent years has also helped counteract the processes that facilitate extreme heavy ice years. The recent extreme light years within the CAA are associated with a longer navigation season within the Northwest Passage.


2020 ◽  
Vol 61 (82) ◽  
pp. 154-163
Author(s):  
Qing Li ◽  
Chunxia Zhou ◽  
Lei Zheng ◽  
Tingting Liu ◽  
Xiaotong Yang

AbstractThe evolution of melt ponds on Arctic sea ice in summer is one of the main factors that affect sea-ice albedo and hence the polar climate system. Due to the different spectral properties of open water, melt pond and sea ice, the melt pond fraction (MPF) can be retrieved using a fully constrained least-squares algorithm, which shows a high accuracy with root mean square error ~0.06 based on the validation experiment using WorldView-2 image. In this study, the evolution of ponds on first-year and multiyear ice in the Canadian Arctic Archipelago was compared based on Sentinel-2 and Landsat 8 images. The relationships of pond coverage with air temperature and albedo were analysed. The results show that the pond coverage on first-year ice changed dramatically with seasonal maximum of 54%, whereas that on multiyear ice changed relatively flat with only 30% during the entire melting period. During the stage of pond formation, the ponds expanded rapidly when the temperature increased to over 0°C for three consecutive days. Sea-ice albedo shows a significantly negative correlation (R = −1) with the MPF in melt season and increases gradually with the refreezing of ponds and sea ice.


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