Sea Ice in Canada

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Sea ice is a prominent feature in the Canadian Arctic. It consists of ice that grows and melts each year (i.e., first-year ice) and ice that remains present all-year round (i.e., multi-year ice). The amount and type of sea ice present, notably the total minimum area it covers in the summer, impacts human activity and biological habitat.

Over the past five decades, the area covered by sea ice in the Canadian Arctic, measured during the summer season,Footnote [1] has been decreasing. Between 1968 and 2015, sea ice area in the Northern Canadian WatersFootnote [2] declined at a rate of 6.8% per decade. In 2015, the average sea ice area in the Northern Canadian Waters was 1.12 million square kilometres (km2) or 30% of the total area.

Average sea ice area, Northern Canadian Waters, 1968 to 2015

1968 to 2015 Scatter Chart -  See long description below.

Long description

The chart shows the annual average sea ice area in millions of square kilometres in the Northern Canadian Waters from 1968 to 2015. A line is also presented showing a decreasing trend of 6.8% per decade in sea ice area over the 48-year time period.

Data for this chart
Average sea ice area, Northern Canadian Waters, 1968 to 2015
YearNorthern Canadian Waters sea ice area (millions of square kilometres)
19681.25
19691.49
19701.47
19711.29
19721.68
19731.31
19741.46
19751.31
19761.47
19771.27
19781.68
19791.43
19801.40
19811.17
19821.34
19831.60
19841.46
19851.34
19861.54
19871.39
19881.25
19891.41
19901.44
19911.42
19921.63
19931.30
19941.34
19951.19
19961.52
19971.27
19980.86
19991.10
20001.23
20011.22
20021.27
20031.20
20041.28
20051.17
20060.98
20070.94
20080.90
20091.14
20100.83
20110.74
20120.70
20131.12
20141.04
20151.12

Download data file (Excel/CSV; 1.10 KB)

How this indicator was calculated

Note: Sea ice is measured during the summer season. For the Northern Canadian Waters, the summer season is defined as the period from June 19 to November 19 for the Hudson Bay domain and from June 25 to October 15 for the Canadian Arctic domain. A statistically significant trend is reported when the Mann-Kendall test indicated the presence of a trend at the 95% confidence level.
Source: Environment and Climate Change Canada (2016) Climate Research Division.

Arctic sea ice decline is the result of a combination of factors. Human-induced warming from greenhouse gas emissions and climate variability has resulted in an unprecedented loss of Arctic sea ice within the last 50 years in comparison to the last 1450 years.

The Arctic region is very sensitive to climate change because of feedback involving sea ice that influences the reflectivity of the Earth's surface. As sea ice area declines due to warming temperatures, darker ocean surfaces are exposed that can absorb more sunlight and in turn cause more warming and sea ice melting. This feedback cycle is an important factor in amplifying Arctic temperatures. Research has shown that the loss of Arctic sea ice is a very significant contributor to the recent amplification of Arctic temperature change compared to the global average.

Changes in the amount of sea ice, the location of ice edges and the timing of seasonal cycles have complex, cascading ecosystem impacts. Sea ice declines result in a loss of wildlife habitat, as it serves as hunting platforms for polar bears and as resting grounds and nursery areas for walruses and seals. Algae that grow on the underside of sea ice are also important to the marine food supply.

These changes also have an impact on safety of northerners who use sea ice as a transportation route or platform for hunting/fishing. More than ever, decisions on whether to go out on the ice must be made on the basis of weather and sea ice condition reports, as northerners can no longer rely on traditional knowledge of when it is safe to venture out on the ice.

Regional sea ice

In the Northern Canadian Waters, the area covered by sea ice, measured during the summer season,Footnote [1] varies by location. Some sub-regions, such as the Canadian Artic Archipelago and Kane Basin, usually remain largely covered by ice in the summer while other sub-regions, such as the four sub-regions on the Hudson Bay domain (Hudson Bay, Hudson Strait, Davis Strait and Northern Labrador Sea) are typically sea ice free.

Despite these regional variations, all sub-regions within the Northern Canada Waters have statistically significant decreasing trends in sea ice coverage over the 1968 to 2015 period, ranging from a 3% decrease per decade in the Kane Basin to a 17% decrease per decade in the Northern Labrador Sea.

Sub-region sea ice area trends, Northern Canadian Waters, 1968 to 2015

Map of Canada showing regions of Canadian Arctic and Hudson Bay with inset charts - See long description below.

Long description

The map shows the sub-regions of the Canadian Arctic and Hudson Bay domains (Northern Canadian Waters) for the regional sea ice area indicators. The five sub-regions of the Canadian Arctic domain are Baffin Bay, Foxe Basin, Kane Basin, Beaufort Sea and Canadian Arctic Archipelago. The four sub-regions of the Hudson Bay domain are the Hudson Strait, Hudson Bay, Davis Strait and Northern Labrador Sea. For each sub-region, an inset line chart shows the proportion of sea ice covering the total area of the sub-region and the sea ice area in thousands of square kilometres from 1968 to 2015. Statistically significant decreasing trends in sea ice area were found for each of the nine sub-regions.

Data for this chart
Sub-region sea ice area trends, Northern Canadian Waters, 1968 to 2015
YearFoxe Basin sea ice area (thousands of square kilometres)Kane Basin sea ice area (thousands of square kilometres)Baffin Bay sea ice area (thousands of square kilometres)Beaufort Sea sea ice area (thousands of square kilometres)Canadian Arctic Archipelago sea ice area (thousands of square kilometres)Hudson Bay sea ice area (thousands of square kilometres)Hudson Strait sea ice area (thousands of square kilometres)Davis Strait sea ice area (thousands of square kilometres)North Labrador sea ice area (thousands of square kilometres)
196883311433115429421255
1969593217243154419125345
19707434216390556130193812
1971663317735448210930319
197211733171335659223507715
1973643415737547612530493
197468348547858715427237
197553348745752010917278
1976823414742759711319417
197773352102865158415416
19781083121041264919430357
1979763313932766212722376
1980623314941758111017283
1981443112735347110414282
1982633215829955814224586
19839035187453539162388112
19846531124442538154415212
1985563085459513133272410
1986723317939762216521423
1987863018827558715826327
1988662812137949211223265
1989813517738853714120285
1990862615337759212831387
19916933108467553122273412
1992793815145061221032557
1993683121225352614221424
1994562914043751111619316
199556251692845319412140
1996613525845453812122296
1997493515631257610216173
199858321401553925510131
19995931144335458378275
20004732944065061078242
20015734102425522516181
200259347935856412615289
20035230743525561039182
2004613210131459814711160
200540301123545496410101
2006282964360436464121
20075425962424087610185
20085926921584359414240
200952226930650513917286
201039297923340833390
201145257319034059360
2012522943126353746180
2013573567339504849175
20146125522605208612135
2015653512826141814018473
1968–2015 decadal trend-7.3%-2.9%-12.7%-6.6%-4.4%-9.6%-15.1%-13.4%-16.9%

Download data file (Excel/CSV; 2.85 KB)

How this indicator was calculated

Note: Sea ice is measured during the summer season. For the Northern Canadian Waters, the summer season is defined as the period from June 19 to November 19 for the Hudson Bay domain and from June 25 to October 15 for the Canadian Arctic domain. A statistically significant trend is reported when the Mann-Kendall test indicated the presence of a trend at the 95% confidence level.
Source: Environment and Climate Change Canada (2016) Climate Research Division.

In absolute terms, the largest sea ice area loss over the 1968 to 2015 period was found in the Beaufort Sea sub-region, where about 137 000 km2 of sea ice area was lost. The Canadian Arctic Archipelago, Baffin Bay and Hudson Bay sub-regions also lost a large amount of sea ice area over the same period, with a detected loss of about 124 000 km2, 109 000 km2 and 72 000 km2, respectively.

Multi-year sea ice

Multi-year sea ice is ice that has survived at least one summer's melt. Multi-year sea ice contains less salt and is usually thicker than first-year sea ice. Because it contains less salt, it is harder and more difficult for icebreakers to navigate and clear.

In the Canadian Arctic domain, multi-year sea ice, measured during the summer season,Footnote [3] declined by 6.9% per decade over the 1968 to 2015 period, while total sea ice declined by 6.1% per decade over the same period. Overall, the Arctic is shifting from a predominantly thick multi-year ice to a thinner ice dominated by first-year ice.

Average multi-year sea ice area, Canadian Arctic domain, 1968 to 2015

Scatter chart with a decreasing trend - see long description below

Long description

The chart shows the annual average multi-year sea ice area in thousands of square kilometres in the Canadian Arctic domain from 1968 to 2015. A line is also presented showing a decreasing trend of 6.9% per decade in multi-year sea ice area over the 48-year time period.

Data for this chart
Average multi-year sea ice area, Canadian Arctic domain, 1968 to 2015
YearCanadian Arctic domain multi-year sea ice area (thousands of square kilometres)
1968487
1969659
1970513
1971490
1972454
1973537
1974498
1975631
1976625
1977503
1978548
1979626
1980671
1981484
1982368
1983576
1984528
1985492
1986539
1987557
1988580
1989545
1990616
1991669
1992680
1993603
1994596
1995496
1996671
1997619
1998392
1999334
2000414
2001569
2002486
2003516
2004534
2005556
2006489
2007370
2008260
2009351
2010344
2011250
2012201
2013295
2014405
2015391

Download data file (Excel/CSV; 1011 B)

How this indicator was calculated

Note: Sea ice is measured during the summer season. The summer season is defined as the period from June 25 to October 15 for the Canadian Arctic domain. A statistically significant trend is reported when the Mann-Kendall test indicated the presence of a trend at the 95% confidence level.
Source: Environment and Climate Change Canada (2016) Climate Research Division.

Regional multi-year sea ice

In the Canadian Arctic domain, decreasing trends in multi-year sea ice, measured during the summer season,Footnote [3] were found for the Foxe Basin, Kane Basin, Beaufort Sea and Canadian Arctic Archipelago sub-regions. The Baffin Bay sub-region showed no increasing or decreasing trends from 1968 to 2015. The sub-regions of the Hudson Bay domain were found to be free of multi-year ice over the whole time period.

Multi-year sea ice area in Canadian Arctic sub-regions, 1968 to 2015

Map of Canada showing Canadian Arctic domain with inset charts - see long description below

Long description

The map shows the sub-regions of the Canadian Arctic domain (Baffin Bay, Foxe Basin, Kane Basin, Beaufort Sea and Canadian Arctic Archipelago). For each sub-region, an inset line chart shows the proportion of multi-year sea ice covering the total area of the sub-region and the multi-year sea ice area in thousands of square kilometres from 1968 to 2015. Statistically significant decreasing trends in multi-year sea ice area were found at four sub-regions (Foxe Basin, Kane Basin, Beaufort Sea and Canadian Arctic Archipelago). The Baffin Bay sub-region did not show a statistically significant decrease or increase in multi-year sea ice area.

Data for this chart
Multi-year sea ice area in Canadian Arctic sub-regions, 1968 to 2015
YearFoxe Basin multi-year sea ice area(thousands of square kilometres)Kane Basin multi-year sea ice area(thousands of square kilometres)Baffin Bay multi-year sea ice area(thousands of square kilometres)Beaufort Sea multi-year sea ice area(thousands of square kilometres)Canadian Arctic Archipelago multi-year sea ice area(thousands of square kilometres)
19681.58178216244
19690.142328319289
19700.321423234243
19710.831616256201
19723.771411181243
19730.881915202301
19740.18166285190
19750.45165374235
19762.46179350247
19770.161415181293
19784.16149240281
19795.881510213383
19800.26188291354
19810.351618213237
19820.221216140201
19833.912144252255
19840.571416287211
19850.43132271207
19861.09119265253
19870.77138190346
19880.66108253308
19890.241710245273
19900.791751260288
19911.7467340313
19921.492812320318
19931.372460190328
19943.852013281279
19950.651743203233
19960.671848344260
19970.212222255320
19980.021732103240
19990.401313205102
20000.16158239151
20010.031712308232
20020.001810229228
20030.11148232263
20040.251816205294
20050.39147240295
20060.261312254208
20070.001327163168
20080.04111779152
20090.06910164168
20100.021427134169
20110.00129111119
20120.1013477106
20130.16125146131
20140.22115178212
20150.131512191172
1968–2015 decadal trend-18.7%-4.7%No trend-7.6%-7.1%

Download data file (Excel/CSV; 2.01 KB)

How this indicator was calculated

Note: Sea ice is measured during the summer season. The summer season is defined as the period from June 25 to October 15 for the Canadian Arctic domain. A statistically significant trend is reported when the Mann-Kendall test indicated the presence of a trend at the 95% confidence level.
Source: Environment and Climate Change Canada (2016) Climate Research Division.

Sea ice area in Canada's Northwest Passage

Canada's Northwest Passage is a system of gulfs, straits, sounds and channels in the Canadian Arctic Archipelago connecting the Beaufort Sea in the west with Baffin Bay in the east. It presents a potential deep-water Arctic shipping route between the northern Pacific and Atlantic regions that is much shorter than routes through the Panama or Suez canals. The Northwest Passage is covered by floating or land-fast sea iceFootnote [4] for most of the year, making it a navigation obstacle for ice-breaking ships and a safety hazard for non-ice strengthened ships. As illustrated below, the Northwest Passage provides two main navigation paths on its western side: a northern route and a southern route.

Canada's Northwest Passage

Map of Northwest Passage - see long description below.

Long description

The map shows the northern and southern routes of the Northwest Passage across Canada's Arctic Archipelago.

Over the 1968 to 2015 period, the amount of sea ice area covering the Northwest Passage, measured during the summer season,Footnote [3] fluctuated in a similar fashion to the rest of the Canadian Arctic Waters. Indeed, statistical decreasing trends of 3% and 7% were detected over this period for the northern and southern routes of the Northwest Passage.

For multi-year sea ice, a decreasing trend of 8% per decade was detected for the northern route, while a decreasing trend of 11% was detected for the southern route. The southern route was virtually free of multi-year sea ice for many of the years.

Average sea ice and multi-year sea ice area, Canada's Northwest Passage, 1968 to 2015

Two line charts showing average and multi-year sea ice area in the Northwest Passage - see long description below.

Long description

The line charts show the average sea ice area and the multi-year sea ice area of the northern and southern routes of the Northwest Passage from 1968 to 2015. Statistically significant decreasing trends are also presented for the northern and southern routes in both charts.

Data for this chart
Average sea ice and multi-year sea ice area, Canada's Northwest Passage, 1968 to 2015
YearNorthwest Passage northern route sea ice area (thousands of square kilometres)Northwest Passage southern route sea ice area (thousands of square kilometres)Northwest Passage northern route multi-year sea ice area (thousands of square kilometres)Northwest Passage southern route multi-year sea ice area (thousands of square kilometres)
196812781648
196913386824
197013098557
197111069407
19721461476113
1973119637719
1974132134367
1975138876512
19761381237314
1977124817722
19781591426231
19791581559242
19801391157736
1981117675310
1982131110409
19831281105017
198413894486
19851231025513
19861411376726
19871451199630
1988126628414
19891271026916
19901431147626
19911341128033
19921451208421
1993129898422
1994129888719
1995132856913
1996134906923
19971471049322
199894556019
199910770124
200011993263
200113783647
20021401115310
2003136987714
20041401229119
20051361088623
200611653667
20079858444
200810462325
200911987305
20108155216
20116950151
20127456201
201312379232
201412684328
20159159277
1968–2015 decadal trend-3.4%-7.3%-8.0%-10.9%

Download data file (Excel/CSV; 1.73 KB).

How this indicator was calculated

Note: Sea ice is measured during the summer season. The summer season is defined as the period from June 25 to October 15 for the Arctic domain. A statistically significant trend is reported when the Mann-Kendall test indicated the presence of a trend at the 95% confidence level.
Source: Environment and Climate Change Canada (2016) Climate Research Division.

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