Landfast Sea Ice Conditions in the Canadian Arctic: 1983 – 2009

We used Canadian Ice Service (CIS) digital charts from 1983 to 2009 to create a climatology of landfast sea ice in the Canadian Arctic. The climatology characterized the spatial distribution and variability of landfast ice through an average annual cycle and identified the mean onset date, breakup date, and duration of landfast ice. Trends in date and duration of onset and breakup were calculated over the 26-year period on the basis of CIS regions and sub-regions. In several sub-regions— particularly in the Canadian Arctic Archipelago—we calculated significant trends towards later landfast ice onset or earlier breakup, or both. These later onset and earlier breakup dates translated into significant decreases in landfast ice duration for many areas of the Canadian Arctic. For communities located in the most affected areas, including Tuktoyaktuk, Kugluktuk, Cambridge Bay, Gjoa Haven, Arctic Bay, and Pond Inlet, this shorter landfast ice season is of significant social, cultural, and economic importance. Landfast sea-ice duration in the interior of the Northwest Passage has not undergone any statistically significant decrease over the time series.Nous nous sommes appuyés sur les cartes numériques du Service canadien des glaces (SCG) pour les années 1983 à 2009 afin de produire la climatologie de la glace de mer de l’Arctique canadien. La climatologie permet de caractériser la distribution spatiale et la variabilité de la glace de mer au moyen d’un cycle annuel moyen, et de déterminer la date moyenne du commencement, la date de la débâcle et la durée de la glace de mer. Les tendances en matière de dates et de durées relativement au commencement et à la débâcle ont été calculées sur la période de 26 ans en fonction des régions visées par le SCG et des sous-régions. Dans plusieurs sous-régions — plus particulièrement dans l’archipel Arctique canadien — nous avons calculé d’importantes tendances indiquant des dates de commencement plus tardives de la glace de mer ou des dates de débâcle plus hâtives, ou les deux. Ces dates plus hâtives et plus tardives se traduisent par la réduction considérable de la durée de la glace de mer en maints endroits de l’Arctique canadien. Pour les localités situées dans la plupart des régions touchées, dont Tuktoyaktuk, Kugluktuk, Cambridge Bay, Gjoa Haven, Arctic Bay et Pond Inlet, cette saison de glace de mer plus courte revêt une grande importance sur les plans social, culturel et économique. Du point de vue statistique, la durée de la glace de mer à l’intérieur du passage du Nord-Ouest n’a pas connu de réduction importante au cours de cette période

Evaluating RADARSAT-2 for the Monitoring of Lake Ice Phenology Events in Mid-Latitudes

Lake ice is an important component in understanding the local climate as changes in temperature have an impact on the timing of key ice phenology events. In recent years, there has been a decline in the in-situ monitoring of lake ice events in Canada and microwave remote sensing imagery from synthetic aperture radar (SAR) is more widely used due to the high spatial resolution and response of backscatter to the freezing and melting of the ice surface. RADARSAT-2 imagery was used to develop a threshold-based method for determining lake ice events for mid-latitude lakes in Central Ontario from 2008 to 2017. Estimated lake ice phenology events are validated with ground-based observations and are compared against the Moderate Resolution Imaging Spectroradiometer (MODIS band 2). The threshold-based method was found to accurately identify 12 out of 17 freeze events and 13 out of 17 melt events from 2015–2017 when compared to ground-based observations. Mean absolute errors for freeze events ranged from 2.5 to 10.0 days when compared to MODIS imagery while the mean absolute error for water clear of ice (WCI) ranged from 1.5 to 7.1 days. The method is important for the study of mid-latitude lake ice due to its unique success in detecting multiple freeze and melting events throughout the ice season

Evaluation of the Interactive Multisensor Snow and Ice Mapping System (IMS) for monitoring sea ice phenology

AbstractWe present an evaluation of the Interactive Multisensor Snow and Ice Mapping System (IMS) for monitoring northern hemisphere sea ice phenology. Analysts utilize a variety of datasets to manually derive the daily extent of snow, ice, water and land, available at both 24 and 4km. The 4km IMS product was assessed for 2004–2008 against several previously established melt/freeze algorithms using Scatterometer Image Reconstruction (SIR) SeaWinds/QuikSCAT (QuikSCAT) backscatter (σ°), Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) brightness temperature (TB) measurements, data from the Special Sensor Microwave/Image data (SSM/I) and sea ice concentrations derived from DMSP Special Sensor Microwave/Imager–Special Sensor Microwave Imager Sounder (SSMI–SSMIS) data (NASATeam dataset). The resolution possible with the 4km IMS product allows for better spatial representation of sea ice along the coastlines, the ice edges and in the narrow channels of the Canadian Arctic Archipelago as compared to the microwave products. IMS detects open water earlier and freeze onset later than the automated microwave products, and also allows for the detection of opening, and the subsequent closing, of leads that the other datasets are unable to detect. Using RADARSAT-1 imagery for evaluation, IMS is shown to outperform the other datasets for the timing and extent of the first open water detection. IMS identified between 17 and 53% greater open water coverage than the other datasets in the narrow channels of the Northwest Passage (Barrow Strait). In order to further the use of IMS for sea ice applications, we derived two new spatial datasets using the full record of IMS data (4km: 2004–present, 24km: 1997–present): melt duration to open water (duration from melt onset detected with SSM/I passive microwave until open water detected by IMS) and first year ice cover duration (duration from freeze onset until open water, both detected by IMS)

Temporal and Spatial Patterns of Ship Traffic in the Canadian Arctic from 1990 to 2015 + Supplementary Appendix 1: Figs. S1–S7 (See Article Tools)

The limited availability of consistent, longitudinal data sources for marine traffic in Arctic Canada has presented significant challenges for researchers, policy makers, and planners. Temporally and spatially accurate shipping data that reveal historical and current traffic trends are vital to plan safe shipping corridors, develop infrastructure, plan and manage protected areas, and understand the potential environmental and cultural impacts of change, as well as for sovereignty and safety considerations. This study uses a recently developed geospatial database of ship traffic to provide the first synthesized overview of the spatial and temporal variability of different vessel types in Arctic Canada during the 26-year period from 1990 to 2015. This examination shows that, overall, the distance traveled by ships in Arctic Canada nearly tripled (from 364 179 km in 1990 to 918 266 km in 2015), that the largest proportion of ship traffic in the region is from general cargo vessels and government icebreakers (including research ships), and that the fastest growing vessel type by far is pleasure craft (private yachts). Spatial shifts in vessel activity over the last quarter century have favoured areas with active mine sites, as well as the southern route of the Northwest Passage. As a result, some communities, including Baker Lake, Chesterfield Inlet, Pond Inlet, and Cambridge Bay, are experiencing greater increases in ship traffic.La faible disponibilité de sources de données longitudinales cohérentes pour le trafic maritime de l’Arctique canadien pose d’importants défis aux chercheurs, aux responsables des politiques et aux planificateurs. L’existence de données d’expédition temporelles et spatiales précises qui révèlent les tendances historiques et actuelles du trafic s’avère essentielle pour planifier la sûreté des couloirs de navigation, aménager l’infrastructure, planifier et gérer les zones protégées, comprendre les incidences environnementales et culturelles potentielles découlant du changement et agir en fonction des considérations de souveraineté et de sécurité. Cette étude s’appuie sur une base de données géospatiale du trafic maritime récemment conçue pour fournir la première synthèse de la variabilité spatiale et temporelle de différents types de navires dans l’Arctique canadien au cours de la période de 1990 à 2015. L’étude démontre que, globalement, la distance parcourue par les navires dans l’Arctique canadien a presque triplé (passant de 364 179 km en 1990 à 918 266 km en 2015), que les navires de marchandises diverses et les brise-glaces gouvernementaux (y compris les navires de recherche) forment la plus grande partie du trafic maritime dans la région, et que le trafic des bateaux de plaisance (yachts privés) est, de loin, le trafic qui connaît le plus grand essor. Les changements spatiaux sur le plan de l’activité des navires au cours du dernier quart de siècle ont favorisé les zones ayant des sites miniers actifs, ainsi que la route sud du passage du Nord-Ouest. Par conséquent, certaines collectivités, dont celles de Baker Lake, Chesterfield Inlet, Pond Inlet et Cambridge Bay, connaissent une plus forte augmentation de la circulation maritime

Climate Change 2022: Impacts, Adaptation and Vulnerability: Cross-Chapter Paper 6: Polar Regions

CCP6 assesses the climate change impacts and risks to ecosystems and human systems in Polar Regions, as well as options for adaptation and climate resilient development