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
Year Northern Canadian Waters sea ice area (millions of square kilometres)
1968 1.25
1969 1.49
1970 1.47
1971 1.29
1972 1.68
1973 1.31
1974 1.46
1975 1.31
1976 1.47
1977 1.27
1978 1.68
1979 1.43
1980 1.40
1981 1.17
1982 1.34
1983 1.60
1984 1.46
1985 1.34
1986 1.54
1987 1.39
1988 1.25
1989 1.41
1990 1.44
1991 1.42
1992 1.63
1993 1.30
1994 1.34
1995 1.19
1996 1.52
1997 1.27
1998 0.86
1999 1.10
2000 1.23
2001 1.22
2002 1.27
2003 1.20
2004 1.28
2005 1.17
2006 0.98
2007 0.94
2008 0.90
2009 1.14
2010 0.83
2011 0.74
2012 0.70
2013 1.12
2014 1.04
2015 1.12

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
Year Foxe 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)
1968 83 31 143 311 542 94 21 25 5
1969 59 32 172 431 544 191 25 34 5
1970 74 34 216 390 556 130 19 38 12
1971 66 33 177 354 482 109 30 31 9
1972 117 33 171 335 659 223 50 77 15
1973 64 34 157 375 476 125 30 49 3
1974 68 34 85 478 587 154 27 23 7
1975 53 34 87 457 520 109 17 27 8
1976 82 34 147 427 597 113 19 41 7
1977 73 35 210 286 515 84 15 41 6
1978 108 31 210 412 649 194 30 35 7
1979 76 33 139 327 662 127 22 37 6
1980 62 33 149 417 581 110 17 28 3
1981 44 31 127 353 471 104 14 28 2
1982 63 32 158 299 558 142 24 58 6
1983 90 35 187 453 539 162 38 81 12
1984 65 31 124 442 538 154 41 52 12
1985 56 30 85 459 513 133 27 24 10
1986 72 33 179 397 622 165 21 42 3
1987 86 30 188 275 587 158 26 32 7
1988 66 28 121 379 492 112 23 26 5
1989 81 35 177 388 537 141 20 28 5
1990 86 26 153 377 592 128 31 38 7
1991 69 33 108 467 553 122 27 34 12
1992 79 38 151 450 612 210 32 55 7
1993 68 31 212 253 526 142 21 42 4
1994 56 29 140 437 511 116 19 31 6
1995 56 25 169 284 531 94 12 14 0
1996 61 35 258 454 538 121 22 29 6
1997 49 35 156 312 576 102 16 17 3
1998 58 32 140 155 392 55 10 13 1
1999 59 31 144 335 458 37 8 27 5
2000 47 32 94 406 506 107 8 24 2
2001 57 34 102 425 522 51 6 18 1
2002 59 34 79 358 564 126 15 28 9
2003 52 30 74 352 556 103 9 18 2
2004 61 32 101 314 598 147 11 16 0
2005 40 30 112 354 549 64 10 10 1
2006 28 29 64 360 436 46 4 12 1
2007 54 25 96 242 408 76 10 18 5
2008 59 26 92 158 435 94 14 24 0
2009 52 22 69 306 505 139 17 28 6
2010 39 29 79 233 408 33 3 9 0
2011 45 25 73 190 340 59 3 6 0
2012 52 29 43 126 353 74 6 18 0
2013 57 35 67 339 504 84 9 17 5
2014 61 25 52 260 520 86 12 13 5
2015 65 35 128 261 418 140 18 47 3
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
Year Canadian Arctic domain multi-year sea ice area (thousands of square kilometres)
1968 487
1969 659
1970 513
1971 490
1972 454
1973 537
1974 498
1975 631
1976 625
1977 503
1978 548
1979 626
1980 671
1981 484
1982 368
1983 576
1984 528
1985 492
1986 539
1987 557
1988 580
1989 545
1990 616
1991 669
1992 680
1993 603
1994 596
1995 496
1996 671
1997 619
1998 392
1999 334
2000 414
2001 569
2002 486
2003 516
2004 534
2005 556
2006 489
2007 370
2008 260
2009 351
2010 344
2011 250
2012 201
2013 295
2014 405
2015 391

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
Year Foxe 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)
1968 1.58 17 8 216 244
1969 0.14 23 28 319 289
1970 0.32 14 23 234 243
1971 0.83 16 16 256 201
1972 3.77 14 11 181 243
1973 0.88 19 15 202 301
1974 0.18 16 6 285 190
1975 0.45 16 5 374 235
1976 2.46 17 9 350 247
1977 0.16 14 15 181 293
1978 4.16 14 9 240 281
1979 5.88 15 10 213 383
1980 0.26 18 8 291 354
1981 0.35 16 18 213 237
1982 0.22 12 16 140 201
1983 3.91 21 44 252 255
1984 0.57 14 16 287 211
1985 0.43 13 2 271 207
1986 1.09 11 9 265 253
1987 0.77 13 8 190 346
1988 0.66 10 8 253 308
1989 0.24 17 10 245 273
1990 0.79 17 51 260 288
1991 1.74 6 7 340 313
1992 1.49 28 12 320 318
1993 1.37 24 60 190 328
1994 3.85 20 13 281 279
1995 0.65 17 43 203 233
1996 0.67 18 48 344 260
1997 0.21 22 22 255 320
1998 0.02 17 32 103 240
1999 0.40 13 13 205 102
2000 0.16 15 8 239 151
2001 0.03 17 12 308 232
2002 0.00 18 10 229 228
2003 0.11 14 8 232 263
2004 0.25 18 16 205 294
2005 0.39 14 7 240 295
2006 0.26 13 12 254 208
2007 0.00 13 27 163 168
2008 0.04 11 17 79 152
2009 0.06 9 10 164 168
2010 0.02 14 27 134 169
2011 0.00 12 9 111 119
2012 0.10 13 4 77 106
2013 0.16 12 5 146 131
2014 0.22 11 5 178 212
2015 0.13 15 12 191 172
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
Year Northwest 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)
1968 127 81 64 8
1969 133 86 82 4
1970 130 98 55 7
1971 110 69 40 7
1972 146 147 61 13
1973 119 63 77 19
1974 132 134 36 7
1975 138 87 65 12
1976 138 123 73 14
1977 124 81 77 22
1978 159 142 62 31
1979 158 155 92 42
1980 139 115 77 36
1981 117 67 53 10
1982 131 110 40 9
1983 128 110 50 17
1984 138 94 48 6
1985 123 102 55 13
1986 141 137 67 26
1987 145 119 96 30
1988 126 62 84 14
1989 127 102 69 16
1990 143 114 76 26
1991 134 112 80 33
1992 145 120 84 21
1993 129 89 84 22
1994 129 88 87 19
1995 132 85 69 13
1996 134 90 69 23
1997 147 104 93 22
1998 94 55 60 19
1999 107 70 12 4
2000 119 93 26 3
2001 137 83 64 7
2002 140 111 53 10
2003 136 98 77 14
2004 140 122 91 19
2005 136 108 86 23
2006 116 53 66 7
2007 98 58 44 4
2008 104 62 32 5
2009 119 87 30 5
2010 81 55 21 6
2011 69 50 15 1
2012 74 56 20 1
2013 123 79 23 2
2014 126 84 32 8
2015 91 59 27 7
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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