Sea ice extent near both poles was again below average, but higher than in recent years for most of the month. In the Arctic, seasonal sea ice loss began more slowly in May than in the recent years as air temperatures were closer to the 1981 to 2010 average. In the Antarctic, a slowdown in ice growth late in the month quickly brought sea ice extent levels close to record lows.

Overview of conditions

Figure 1. Arctic sea ice extent for May 2022 was 12.88 million square kilometers (4.97 million square miles). The magenta line shows the 1981 to 2010 average extent for that month. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

Average Arctic sea ice extent for May 2022 was 12.88 million square kilometers (4.97 million square miles) (Figure 1). This was 410,000 square kilometers (158,000 square miles) below the 1981 to 2010 average, yet it was the highest May extent since 2013. As was the case for April, sea ice extent was slow to decline, losing only 1.28 million square kilometers (494,000 square miles) during the month. Ice loss in May occurred primarily in the Bering Sea, the Barents Sea, and within Baffin Bay and Davis Strait. However, several openings, or polynyas, in the pack ice have started to form, particularly within the eastern Beaufort Sea, the Chukchi Sea, the Laptev Sea, and around Franz Joseph Land in the northern Barents Sea. Ice also started to pull back from the shores of Russia in the Kara Sea. In Hudson Bay, the ice started to melt out in the south within James Bay and off of Southampton Island in the north. Overall, the daily sea ice extent tracked within the interdecile range (encompassing 90 percent of the 1981 to 2010 daily values) for much of the month. By the end of the month, extent was close to the sea ice extent observed in late May 2012.

Conditions in context

Figure 2a. The graph above shows Arctic sea ice extent as of June 5, 2022, along with daily ice extent data for four previous years and the record low year. 2022 is shown in blue, 2021 in green, 2020 in orange, 2019 in brown, 2018 in magenta, and 2012 in dashed brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
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Figure 2b. This plot shows the departure from average air temperature in the Arctic at the 925 hPa level, in degrees Celsius, for May 2022. Yellows and reds indicate higher than average temperatures; blues and purples indicate lower than average temperatures.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Laboratory
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Figure 2c. This plot shows average sea level pressure in the Arctic in millibars for May 2022. Yellows and reds indicate high air pressure; blues and purples indicate low pressure.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Laboratory
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Through May, sea ice extent was tracking above levels not seen since 2013. The relatively extensive ice cover for this time of year was largely the result of lower than average temperatures in Baffin Bay. Winds from the north also slowed the retreat of ice in the Bering and Barents Seas. Within the Arctic Ocean, air temperatures at the 925 mb level (about 2,500 feet above the surface) were near average over most of the region in May, and 1 to 5 degrees Celsius (2 to 9 degrees Fahrenheit) above the 1981 to 2010 average along the coast of the Kara and East Siberian Seas, the East Greenland Sea, and the Canadian Archipelago (Figure 2b). Areas where openings formed within the ice cover were dominated by off-shore ice motion, pushing ice poleward as well as toward Fram Strait. This offshore ice motion is largely driven by a pattern of low sea level pressure over Eurasia coupled with high pressure over the Pacific sector of the Arctic (Figure 2c).

May 2022 compared to previous years

Figure 3. Monthly May ice extent for 1979 to 2022 shows a decline of 2.5 percent per decade.

Credit: National Snow and Ice Data Center
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May sea ice extent declined by 1.28 million square kilometers (494,000 square miles), or at a rate of 41,200 square kilometers (15,900 square miles) per day, which was slower than the 1981 to 2010 average. This resulted in an average May extent that ranked fourteenth lowest in the satellite record. The downward linear trend in May sea ice extent over the 44-year-satellite record is 33,700 square kilometers (13,000 square miles) per year, or 2.5 percent per decade relative to the 1981 to 2010 average (Figure 3). Based on the linear trend, since 1979, May has lost 450,000 square kilometers (174,000 square miles) of sea ice. This is equivalent to the size of the state of California.

Polynyas help kick-start seasonal ice loss

Figure 4a. This NASA Worldview image from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) on May 29, 2022 shows polynyas forming off the coast of Siberia.

Credit: NASA
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Figure 4b. This plot shows the relationship between averaged sea ice extent from July through October (in blue) and the regional average fire-favorable weather index (FFWI) over the western United States the following autumn and early winter (September to December, in red).

Credit: Zou et al., 2021
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Polynyas have begun to form, providing open water regions that strongly absorb the sun’s energy, warming the near-surface ocean mixed layer, and enhancing lateral ice melt from the sides. One of the larger polynyas is in the Laptev Sea to the west of the New Siberian Islands (Figure 4a). Despite the thin cloud cover, polynyas can be seen at the edge of the landfast ice, ice fastened to the coastline, to the west of the New Siberian Islands as well off the coast of the Taymyr Peninsula between the Kara and Laptev Seas.

A consequence of summer sea ice loss is that the ocean absorbs more of the sun’s energy. Before the ice can form again in the fall and winter, this heat has to be released back to the atmosphere. This is one of the reasons why the Arctic is warming more strongly than the global average, particularly in the fall season. Studies have suggested this amplified Arctic warming may be impacting weather systems at lower latitudes. One hypothesis is that the warm air released from the surface propagates up through the atmosphere and disrupts the polar vortex in the stratosphere. This can lead to cold air outbreaks, such as in February 2021 when cold Arctic air reached as far south as Texas, causing the failure of the power grid, billions of dollars in damage, and loss of lives. Proposed links between Arctic warming and mid-latitude weather nevertheless remain controversial and are far from settled.

Another recent study reveals a correlation between Arctic sea ice extent (averaged from July to October) and conditions favoring California wildfires after removing the long-term trend in both the sea ice and a regional fire-favorable weather conditions index. However, correlation is not causation. This study addresses the potential physical link by examining sensitivity simulations using low and high sea ice years and comparing the atmospheric conditions from climate model runs. The results suggest that during low sea ice minimum years there is tendency for low sea level air pressure over Alaska and high sea level pressure over the western United States. This results in dry and hot air flowing from the south and southwest over California, conditions favorable for wildfires there in the following autumn and early winter (Figure 4b).

Mapping volume of ice and snow over Antarctic sea ice proves difficult

Figure 5a. The graph above shows Antarctic sea ice extent as of June 5, 2022, along with daily ice extent data for four previous years and the record high year. 2022 is shown in blue, 2021 in green, 2020 in orange, 2019 in brown, 2018 in magenta, and 2014 in dashed brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
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Figure 5b. This image shows dual frequency Ku- and Ka-band radar (KuKa) deployed over Antarctic pancake sea ice.

Credit: Povl Abrahamsen
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As reported in a previous post, this year, Antarctic sea ice shrank to the lowest extent in the satellite record at 1.92 million square kilometers (741,000 square miles) on February 25. This event was set against the background of several low minimum extents since 2014. During the month of May, sea ice tracked slightly below the 1981 to 2010 reference period, until late in the month when sea ice autumn growth slowed significantly (Figure 5a). Stronger than average winds from the north and northeast in the Belligshausen and Amundsen Sea regions led to warm conditions near the sea ice edge, inhibiting growth. At month’s end, Antarctic sea ice extent was above only 1980, 1986, 2017, and 2019 in the 44-year record. Sea ice is particularly low in the Amundsen and Weddell Seas.

Reliable information on Antarctic sea ice thickness, important for gaining a fuller understanding of the Antarctic sea ice system, remains elusive. In the Arctic, sea ice thickness can be more accurately estimated using satellite altimeters. However, studies suggest that satellite altimeters may be over-estimating ice thickness compared to ship-based observations. This may be because of the way snow cover on the ice affects the measurements. There are still large uncertainties in the Antarctic snow and sea ice thickness, and hence the overall sea ice volume.

A United Kingdom-led project, called Drivers and Effects of Fluctuations in sea Ice in the ANTarctic (DEFIANT), aims to address this problem. The DEFIANT team is particularly interested in learning how radar waves interact with the snow that covers Antarctic sea ice. A recent DEFIANT field campaign involved three scientists travelling to the Weddell Sea with a radar designed to mimic those mounted on satellites. They investigated radar penetration into snow of different ages, densities, and surface roughness (Figure 5b). The results will help the research community better understand how to measure the underlying sea ice thickness using satellites. In 2023, two DEFIANT-affiliated scientists will spend the entire winter in Antarctica with the same radar instrument, monitoring the snow cover and its radar-reflective properties.

References

Zou, Y., P. J. Rasch, H. Wang, et al. 2021. Increasing large wildfires over the western United States linked to diminishing sea ice in the Arctic. Nature Communications. doi:10.1038/s41467-021-26232-9

Arctic spring melt has begun. Ice extent declined most substantially in the Bering Sea and the Sea of Okhotsk. Overall decline was slower than average through the month.

Overview of conditions

Figure 1. Arctic sea ice extent for April 2022 was 14.06 million square kilometers (5.43 million square miles). The magenta line shows the 1981 to 2010 average extent for that month. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

Average Arctic sea ice extent for April 2022 was 14.06 million square kilometers (5.43 million square miles) (Figure 1). This was 630,000 square kilometers (243,000 square miles) below the 1981 to 2010 average and ranked eleventh lowest in the 44-year satellite record. Extent declined slowly through the beginning of the month, with only 87,000 square kilometers (33,600 square miles) of ice loss between April 1 and April 10. The decline then proceeded at an average pace for this time of year through the reminder of the month. Reductions in sea ice extent during April occurred primarily in the Bering Sea and the Sea of Okhotsk. Other regions had small losses at most. The southern Barents Sea lost some ice, but the channel of open water north of Novaya Zemlya that persisted for much of the winter closed during April. Overall, the daily sea ice extent tracked just below the interdecile range (below 90 percent of past daily values) for the month.

Conditions in context

Figure 2a. The graph above shows Arctic sea ice extent as of May 2, 2022, along with daily ice extent data for four previous years and the record low year. 2022 is shown in blue, 2021 in green, 2020 in orange, 2019 in brown, 2018 in magenta, and 2012 in dashed brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
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Figure 2b. This plot shows the departure from average air temperature in the Arctic at the 925 hPa level, in degrees Celsius, for April 2022. Yellows and reds indicate higher than average temperatures; blues and purples indicate lower than average temperatures.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Laboratory
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Figure 2c. This plot shows average sea level pressure in the Arctic in millibars for April 2022. Yellows and reds indicate high air pressure; blues and purples indicate low pressure.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Laboratory
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Figure 2d. This animation (click to see animation) shows the polynyas, or openings in the ice cover, that formed in the Chukchi Sea from April 12 to 30, 2022. In April, strong offshore winds over the northwest coast of Alaska led to the formation of these polynyas. 

Credit: Agnieszka Gautier, National Snow and Ice Data Center
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During April, temperatures at the 925 mb level (about 2,500 feet above the surface) over the Arctic Ocean were above average. Most areas were 2 to 3 degrees Celsius (4 to 5 degrees Fahrenheit) above average, but in the Beaufort Sea, April temperatures were up to 5 to 6 degrees Celsius (9 to 11 degrees Fahrenheit) above average (Figure 2b). This was accompanied by a strong Beaufort High pressure cell through the month (Figure 2c).

Strong offshore winds over the northwest coast of Alaska led to openings in the ice cover, called polynyas. The first pulse of winds began on March 21. At that time, surface air temperatures were still well below freezing, and the water in the coastal polynya quickly refroze. By April 9, the offshore push of the ice ceased and the polynya iced over completely. However, starting on April 12, a second round of offshore wind pushed the ice away from the coast, initiating another polynya. Refreezing began anew in the open water areas, but the ice growth was noticeably slower, reflecting the higher surface air temperatures by the end of the month (Figure 2d).

April 2022 compared to previous years

Figure 3. Monthly April ice extent for 1979 to 2022 shows a decline of 2.6 percent per decade.

Credit: National Snow and Ice Data Center
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The downward linear trend in April sea ice extent over the 44-year-satellite record is 37,900 square kilometers (14,600 square miles) per year, or 2.6 percent per decade relative to the 1981 to 2010 average (Figure 3). Based on the linear trend, since 1979, April has lost 1.68 million square kilometers (649,000 square miles) of sea ice. This is equivalent to the size of the state of Alaska.

Sea ice age

Figure 4. This map shows the age of Arctic sea ice for the March 12 to 18 period in (a) 1985 and (b) 2022. The oldest ice, greater than 4 years old, is in red. Plot (c) shows the timeseries from 1985 through 2022 of percent cover of the Arctic Ocean domain (inset, purple region) by different sea ice ages during the March 12 to 18 period.

Credit: M. Tschudi, W. Meier, and Stewart, NASA NSIDC DAAC
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With the onset of spring, it is time again for a check-in on sea ice age—the number of years that a parcel of ice has survived summer melt. As noted in previous posts, ice age provides a qualitative assessment of thickness, as older ice has more chances to thicken through ridging, rafting, and bottom ice growth (accretion) during winter. The coverage of the old, thick ice has a significant control on how much total ice survives the summer melt season—the first-year ice that grows thermodynamically over winter is more easily melted away during summer. That which survives through the summer melt season grows in age by one year. The extent of old ice declines through the winter when it drifts out of the Arctic through the Fram or Nares Strait. At the end of last summer, the extent of the oldest ice (greater than 4 years old) tied with 2012 for the lowest in the satellite record. This spring, we continue to see a dominance of first-year ice (Figure 4). The percentage of the greater than 4-year-old ice, which once comprised over 30 percent of the Arctic Ocean, now makes up only 3.1 percent of the ice cover.

Bering Sea crabs

Figure 5. The fishing boat Pinnacle travels through a Bering Sea ice floe on January 25, 2022. Crab fishing is dangerous work due to frequently rough seas, icing, and dense pack ice.

Credit: Loren Holmes/Anchorage Daily News.
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The Bering Sea is an important crab fishery, with several species represented. Crab fishing is dangerous work because of frequently rough seas, icing on the ship’s superstructure, and dense pack ice (Figure 5). This past winter, the population of lucrative snow crabs was down substantially. This decline in crabs appears to be related to low sea ice extent during the 2018 and 2019 winters. Snow crabs prefer cold bottom water that protects the young from predators. The cold-water pool on the Bering Sea floor is caused by winter ice formation where dense, cold, and salty water sinks as the ice grows. However, in 2018 and 2019 there was very little ice. This opened young crabs to more predation, and far fewer survived to maturity.

Antarctica rising

Figure 6. Antarctic sea ice extent for April 2022 was 5.84 million square kilometers (2.25 million square miles). The magenta line shows the 1981 to 2010 average extent for that month. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

After the record low minimum Antarctic sea ice extent at the end of February and the strong heat wave that followed in mid-March, conditions in the Southern Ocean have calmed down. Ice extent remains low for this time of year below the interdecile range, but is above 2017, 2018, and 2019, as well as 1980. Extent remained below average in the Weddell, eastern Ross, and western Amundsen-Bellingshausen regions, but near average around the rest of the continent (Figure 6). Through April, ice extent increases in all regions around the continent, but with relatively slower growth in the Amundsen-Bellingshausen Seas.

First Multidisciplinary Drifting Observatory for the Study of Arctic Climate science team meeting

Figure 7. The first in-person Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) science conference was held at the end of April in Potsdam, Germany. This was the first chance to present findings from the year-long expedition and pave the way for future analysis and collaboration.

Credit: Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition
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The Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition took place during 2019 and 2020 when the German icebreaker, Polarstern, was frozen into the ice and drifted across the Arctic for nearly a year. During the year, numerous observations were taken of the atmosphere, ocean, sea ice, and biogeochemistry. The scientific analysis is ongoing, and exciting results are starting to be reported.

The first in-person MOSAiC science conference was held at the end of April in Potsdam, Germany (Figure 7). This was the first chance to present findings from the year-long expedition and pave the way for future analysis and collaboration. Science teams from each discipline (atmosphere, ocean, sea ice, snow, remote sensing, ecosystem, biogeochemistry) discussed initial research results. Key to the success of MOSAiC is the strong interdisciplinary collaboration of the projects needed to provide a holistic understanding of Arctic Ocean changes and their impacts. NSIDC scientist Julienne Stroeve presented on the impacts of a rain-on-snow event in mid-September and the potential impact this would have on satellite retrievals of sea ice concentration, snow depth, and ice thickness. In January 2023, all MOSAiC data collected will be made available to the wider science community.

David Barber

Figure 8. Polar scientist David Barber of the University of Manitoba passed away on April 15, 2022.

Credit: University of Manitoba
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It is with sadness that we note the passing of one of the world’s pre-eminent polar scientists, David Barber, of the University of Manitoba, who died on April 15, 2022. He was a force in Canadian science, leading several large projects that increased understanding of sea ice and the Arctic.

References

Bernton, H., and L. Holmes. 2022. A crab boat’s quest for snow crab in a Bering Sea upended by climate change. The Seattle Times. https://pulitzercenter.org/stories/crab-boats-quest-snow-crab-bering-sea-upended-climate-change

Rascoe, A. 2022. Snow crabs in the Bering Sea have been hard to find — partially due to climate change. National Public Radio. https://www.npr.org/2022/04/10/1091927681/snow-crabs-in-the-bering-sea-have-been-hard-to-find-partially-due-to-climate-cha.

Thoman, Jr., R. L., U .S. Bhatt, P. A. Bieniek, B. R. Brettschneider, M. Brubaker, S. L. Danielson, Z. Labe, R. Lader, W. N. Meier, G. Sheffield, and J. E. Walsh. 2020. The record low Bering Sea ice extent in 2018: Context, impacts, and an assessment of the role of anthropogenic climate change. Bulletin of the American Meteorological Society. doi:10.1175/BAMS-D-19-0175.1.

University of Manitoba. 2022. Mourning the loss of visionary Arctic researcher, Dr. David Barber. UM Today News. https://news.umanitoba.ca/mourning-the-loss-of-visionary-arctic-researcher-dr-david-barber/.

Sea ice age data sets from the NSIDC DAAC: Quicklook Arctic Weekly EASE-Grid Sea Ice Age, Version 1 and EASE-Grid Sea Ice Age, Version 4.

After reaching its seasonal maximum extent of 14.88 million square kilometers (5.75 million square miles) on February 25, the seasonal decline in Arctic sea ice extent through March proceeded in fits and starts. By the end of the month, extent saw little change, ending up at 14.50 million square kilometers (5.60 million square miles). The middle of March saw excitement, with several extreme warm events over the Arctic Ocean associated with large transports of water vapor into the region. The Antarctic region also experienced unusual warmth and break up of a small ice shelf.

Overview of conditions

Figure 1. Arctic sea ice extent for March 2022 was 14.59 million square kilometers (5.63 million square miles). The magenta line shows the 1981 to 2010 average extent for that month. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
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Average Arctic sea ice extent for March 2022 was 14.59 million square kilometers (5.63 million square miles), ranking ninth lowest in the satellite record (Figure 1a). The 2022 March extent was 840,000 square kilometers (324,000 square miles) below the 1981 to 2010 average. While extent tracked below the interdecile range of the satellite record throughout the entire month, the total decline, after a series of small ups and downs, was only 250,000 square kilometers (96,500 square miles). Following the pattern seen in February, sea ice extent was below average in the Sea of Okhotsk. Extent in the Bering, Barents, and East Greenland Seas was near average for March.

Conditions in context

Figure 2a. The graph above shows Arctic sea ice extent as of April 4, 2022, along with daily ice extent data for four previous years and the record low year. 2021 to 2022 is shown in blue, 2020 to 2021 in green, 2019 to 2020 in orange, 2018 to 2019 in brown, 2017 to 2018 in magenta, and 2011 to 2012 in dashed brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
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Figure 2b. This plot shows the departure from average air temperature in the Arctic at the 925 hPa level, in degrees Celsius, for March 2022. Yellows and reds indicate higher than average temperatures; blues and purples indicate lower than average temperatures.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Laboratory
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Figure 2c. This plot shows average sea level pressure in the Arctic in millibars for March 2022. Yellows and reds indicate high air pressure; blues and purples indicate low pressure.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Laboratory
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Counter to what might be expected given the very slow rate of sea ice loss over the month as a whole, air temperatures at the 925 millibar level (about 2,500 feet above the surface) were above average over all of the Arctic Ocean (Figure 2b). March temperatures were up to 9 degrees Celsius (16 degrees Fahrenheit) higher than average north of the Canadian Arctic Archipelago, up to 6 degrees Celsius (11 degrees Fahrenheit) above average in the East Siberian Sea, but up to 5 degrees Celsius (9 degrees Fahrenheit) above average over a wide area. The key features of the sea level pressure pattern were high pressure (an anticyclone) over the central Arctic Ocean, a trough of low pressure extending into the Barents Sea, and an unusually high pressure over Northern Europe (Figure 2c). While having an anticyclone over the central Arctic Ocean is quite typical for this time of year, the combination of the high pressure over northern Europe and the pressure trough to the west led to a strong pressure gradient, leading to strong winds from south through the Norwegian and Barents Seas. As discussed below, this can be tied to the extreme warm event over the Arctic Ocean seen in the middle of the month, associated with strong water vapor transport and the passage of several strong cyclones.

March 2022 compared to previous years

Figure 3. Monthly March ice extent for 1979 to 2022 shows a decline of 2.5 percent per decade.

Credit: National Snow and Ice Data Center
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The downward linear trend in March sea ice extent over the 44-year-satellite record is 39,200 square kilometers (15,100 square miles) per year, or 2.5 percent per decade relative to the 1981 to 2010 average. Based on the linear trend, since 1979, March has seen a loss of 1.74 million square kilometers (672,000 square miles). This is equivalent to about the size of Alaska.

Extreme events

Figure 4a. Click on the figure to view the animation of sea level pressure and integrated vapor transport (IVT) near the Greenland Sea. The animation runs from March 11, 2022, through March 17, 2022. Arrows indicate direction and magnitude of transport, while shading indicates the magnitude of the water vapor transport.

Credit: Jessica Voveris, University of Colorado Boulder
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Figure 4b. These maps show sea ice concentration off the eastern coast of Greenland in the Greenland Sea. The map on the left shows sea ice on March 13, 2022, prior to the atmospheric river event passing through. The map on the right is after the event past on March 17, 2022.

Credit: Gunnar Spreen, University of Bremen
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On March 14, air temperatures at the 925 hPa level northwest of Greenland were up to 15 degrees Celsius (27 degrees Fahrenheit) above average. This was part of a series of warm pulses of air moving into the Arctic Ocean from the northern North Atlantic. For example, on March 17, temperatures over the Kara Sea reached 15 degrees Celsius (27 degrees Fahrenheit) above average. Quite often, such warm events are tied to strong transport of water vapor and associated cloud cover. In the animation (Figure 4a-click to view), arrows indicate the direction and magnitude of the integrated vapor transport (IVT) along with sea level pressure from March 11 through March 17, 2022. The shading indicates the magnitude of the transport. Several periods of very strong vapor transport from the northern North Atlantic directly into the Arctic Ocean occurred mid-month; this is consistent with the pattern of strong surface winds from the south through the Norwegian and Barents Seas as implied by the monthly averaged sea level pressure field (Figure 2c). The periods of strong vapor transport are linked to the passage of cyclones (low pressure systems) into the Arctic Ocean. While further analysis is needed, the narrow ribbons of strong water vapor transport into the Arctic Ocean appears to be linked to what are known as atmospheric rivers, which can carry an amount of water vapor far in excess of the discharge of the Mississippi River at its mouth. Atmospheric rivers form in the warm subtropics. The atmospheric circulation pulls the water vapor and forms a narrow band that can be thousands of miles long. When atmospheric rivers reach a coast or flow inland over mountains, the moist air is forced upwards, the water vapor condenses, and heavy precipitation may fall as rain or snow.

There is also evidence, presented at the Arctic Science Summit Week by colleague Gunnar Spreen of the University of Bremen, that the cyclones associated with the strong vapor transport churned up the sea ice in the East Greenland Seas (Figure 4b). Ice concentrations from the University of Bremen AMSR2 product show lower ice concentrations on March 17 compared to March 13 as the passing cyclone broke up ice cover. The result was reduced sea ice concentration and the opening up of numerous leads in the area.

A further look at the Endurance using NSIDC’s Sea Ice Tracking Utility

Figure 5. This map shows ice drift trajectories from January 2010 (green) using NSIDC’s Sea Ice Tracking Utility (SITU) tool. Each track encompasses a two-year period. The drift trajectories are based on observations over the last 40 years or more. The left-most track, for January 2018 through December 2019, follows the actual drift (yellow) of the Endurance in January 1915 to April 1916, but the recent drift tracks are considerably slower. The positions of Elephant Island, where the crew rowed to after leaving the ice, and South Georgia Island, where Shackleton and five others were eventually able to reach civilization, are denoted by stars.

Credit: Walt Meier, NSIDC
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As mentioned in last month’s post, the wreck of the Endurance was found on the floor of the Weddell Sea. The Endurance became trapped in the ice on January 18, 1915, at 76.57 degrees South latitude and 328.5 degrees East longitude. It drifted with the ice over the ensuing months until the ice closed in and began crushing the ship in October. The crew abandoned ship on October 27, 1915, and the Endurance finally sank on November 21, 1915, at 68.64 degrees South latitude, 53.0 West longitude. The crew camped and drifted with the ice until the ice began to break up. They launched lifeboats on April 9, 1916. Fortunately, they were close enough to row to the small uninhabited Elephant Island that at least provided some shelter. Expedition leader Earnest Shackleton and five others then sailed by lifeboat to South Georgia Island, several hundred miles away. After landing, they had to cross by foot over a mountain chain before finally reaching a whaling station. They were eventually able to secure a rescue ship to the rest of the crew on Elephant Island. All crew members were saved.

While the leadership of Earnest Shackleton and the fortitude of the crew where essential to their rescue, they were also fortunate in that the ice drift brought them west as well as north, putting them in proximity of islands off of the Antarctic Peninsula. NSIDC’s Sea Ice Tracking Utility (SITU) is a tool that allows us to investigate the drift of the ice based on observations over the last 40 or more years. The tool was developed at NSIDC in collaboration with colleagues Stephanie Pfirman (Arizona State University), Bruno Tremblay (McGill University), and Bob Newton (Columbia University). We can examine whether the drift of Shackleton’s ship was a common or rare occurrence using the SITU record. It appears that the drift of the Endurance was rare within the observational record. Starting from the location for the Endurance’s wreck, only one of the drift tracks in the SITU record, from January 2018 through December 2020, would have taken the crew so far north and west—toward the potential haven of Elephant Island. Other SITU tracks would have taken the crew further from land and toward the open ocean. Additionally, the drift of the Shackleton crew was particularly fast—they came out of the ice within about 14 months. The observed drift from 1979 through 2020 in SITU would keep them in the ice for at least two years. This means that the crew would not have been able to get to Elephant Island in late spring but would have had to winter over on the ice, possibly for several more months.

Strong warming event brings record-setting temperatures to East Antarctica

Figure 6a. These weather maps show the heat wave event of March 16 to 18 in Antarctica. Map (a) shows temperature difference from average for the date; map (b) shows wind pattern at 500 millibar (about 18,000 feet) showing the far southern excursion of the westerly wind belt over Wilkes Land and far up onto the East Antarctic Plateau.

Credit: University of Maine, National Oceanic and Atmospheric Administration (NOAA)
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Figure 6b. This weather map shows the atmospheric river event over Antarctica on March 16, 2022. At 16:00 Coordinated Universal Time (UTC) the atmospheric river of water vapor flowed onto the East Antarctic coast.

Credit: University of Maine, National Oceanic and Atmospheric Administration (NOAA)
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Between March 16 and 18, a combination of an unusual high-pressure region southeast of New Zealand and a strong low pressure south of Perth, Australia, led to a pulse of warm and moist air from east Australia (the Tasman Sea) to the Antarctic coastline and up onto the East Antarctic Plateau (Figure 6a). As the pulse of air, another example of what appears to be an atmospheric river, reached the coast, sustained periods of above-freezing temperatures and rain were observed at the coastal bases (Figure 6b). Air temperatures at Casey and Dumont D’Urville Stations, were above freezing for nearly two days at 6 degrees Celsius (43 degrees Fahrenheit) and 4 degrees Celsius (39 degrees Fahrenheit), respectively. Because of the high moisture content of the air mass, temperatures remained high as the air climbed onto the ice sheet. Precipitation, and the heat released by condensation of moisture, kept the air warm as it moved up onto the plateau, bringing temperatures far above those typical for mid-March. Temperatures at high-elevation stations such as Russia’s Vostok Station and the European station at Dome Concordia, were more than 35 degrees Celsius (63 degrees Fahrenheit) above average for this time of year.

Ice shelf in eastern Wilkes Land breaks up

Figure 7. These images from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on the NASA Terra Satellite show the before and after details of the Conger Ice Shelf break up. Images are 188 kilometers (117 miles) on a side, north is to the lower right. Conger Ice Shelf is near 66 degrees South, 103 degrees East longitude.

Credit: NASA Worldview
High-resolution image

After many years of rifting and small calvings, the Conger Ice Shelf, at the eastern end of the Wilkes Land coast and just east of the Shackleton Ice Shelf, has calved into several large pieces and two named icebergs, C-37 and C-38. The ice shelf was about 1,200 square kilometers (463 square miles) in area towards the end but had been losing area over several years. The flow of the glacier pushed the ice shelf front against a small island, Bowman Island, just off the coast of Antarctica. The stress of the floating ice shelf being pushed against the snow-covered rock island caused large rifts to form and eventually forced pieces to break away. This is an example of what happens when a strong force (continental ice sheet flow) impinges on an immovable object (a rocky island). The event does not appear to be directly related to the recent record low sea ice extent in Antarctica, or the recent heat wave. In fact, the break up occurred just before the warm event.

Reference

Campbell, G. G., S. Pfirman, B. Tremblay, R. Newton, P. DeRepentigny, W. Meier, and C. Fowler. The Ice Tracker. http://icemotion.labs.nsidc.org/SITU

Arctic sea ice has likely reached its maximum extent for the year, at 14.88 million square kilometers (5.75 million square miles) on February 25. The 2022 maximum is the tenth lowest in the 44-year satellite record. On the same day, on the other pole, Antarctic sea ice reached a record minimum extent, at 1.92 million square kilometers (741,000 square miles).

Overview of conditions

Figure 1. Arctic sea ice extent for February 25, 2022, was 14.88 million square kilometers (5.75 million square miles). The orange line shows the 1981 to 2010 average extent for that day. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

On February 25, 2022, Arctic sea ice likely reached its maximum extent for the year, at 14.88 million square kilometers (5.75 million square miles), the tenth lowest extent in the satellite record. This year’s maximum extent is 770,000 square kilometers (297,000 square miles) below the 1981 to 2010 average maximum of 15.65 million square kilometers (6.04 million square miles) and 470,000 square kilometers (182,000 square miles) above the lowest maximum of 14.41 million square kilometers (5.56 million square miles) set on March 7, 2017. Prior to 2019, the four lowest maximum extents occurred from 2015 to 2018.

The date of the maximum this year, February 25, was fifteen days earlier than the 1981 to 2010 average date of March 12. Only two years had an earlier maximum, 1987 and 1996, both on February 24. This year is the second earliest date on the satellite record, tying with 2015, which also reached its maximum extent on February 25.

Conditions in context

Figure 2. The graph above shows Arctic sea ice extent on February 25, 2022, along with daily ice extent data for four previous years and the record low year. 2021 to 2022 is shown in blue, 2020 to 2021 in green, 2019 to 2020 in orange, 2018 to 2019 in brown, 2017 to 2018 in magenta, and 2012 to 2013 in dashed brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
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The ice growth season ended with near average sea ice extent in the Bering Sea, above average in Baffin Bay and off the coast of south-eastern Greenland, and below average in the Barents Sea with a narrow open-water wedge north of Novaya Zemlya. Extent was well below average in the Gulf of St. Lawrence and the Sea of Okhotsk.

Since the maximum on February 25, extent has dropped about 390,000 square kilometers (151,000 square miles), with losses primarily in the Sea of Okhotsk and the Barents Sea. These losses have been offset by gains in the Bering Sea, Baffin Bay, and the Labrador Sea.

Table 1. Ten lowest maximum Arctic sea ice extents (satellite record, 1979 to present)

For the Arctic maximum, which typically occurs in March, the uncertainty range is ~34,000 square kilometers (13,000 square miles), meaning that extents within this range must be considered effectively equal.

The Antarctic minimum

Figure 3. Antarctic sea ice extent for February 25, 2022, was 1.92 million square kilometers (741,000 square miles). The orange line shows the 1981 to 2010 average extent for that day. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

As noted in our previous post, in the Southern Hemisphere, sea ice reached its record minimum extent for the year on the same day, February 25. For the first time in the satellite record, which began in 1979, extent fell below 2 million square kilometers (772,000 square miles) at 1.92 million square kilometers (741,000 square miles). This year’s minimum extent was 190,000 square kilometers (73,400 square miles) below the previous record set on March 3, 2017. The Antarctic minimum extent is 930,000 square kilometers (359,000 square miles) below the 1981 to 2010 average minimum of 2.85 million square kilometers (1.10 million square miles).

The February 25 timing of the minimum was only a day later than the 1981 to 2010 median date of February 24 for the minimum. Over the satellite record, the Antarctic minimum has occurred as early as February 15 and as late as March 6.

Average austral summer air temperatures at the 925 mb level (about 2,500 feet above sea level) over Antarctic sea ice regions have been near average. However, winds have been much stronger and generally in a more northward direction, helping to break up the ice and melt it in warmer ocean waters. One exception was the Weddell Sea, where winds came more from the north, but that served to push the ice edge southward, reducing extent near the Antarctic Peninsula.

Since the minimum on February 25, ice growth has progressed at a near-average rate with growth around most of the continent, except off the coast of Dronning Maud Land and Enderby Land, which lie to the south of Africa.

Final analysis pending

Please note this is a preliminary announcement. At the beginning of April, NSIDC scientists will release a full analysis of winter conditions in the Arctic, along with monthly data for March.

Arctic sea ice is approaching its seasonal peak, with below-average sea ice extent in the Barents Sea and the Sea of Okhotsk, but near-average ice extent elsewhere. Antarctic sea ice extent set a record low minimum for the satellite data era. However, two regions of high interest to researchers remained locked in ice: Thwaites Glacier and the central Weddell Sea.

Overview of conditions

Figure 1a. Arctic sea ice extent for February 2022 was 14.61 million square kilometers (5.64 million square miles). The magenta line shows the 1981 to 2010 average extent for that month. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

Figure 1b. The graph above shows Arctic sea ice extent as of March 7, 2022, along with daily ice extent data for four previous years and the record low year. 2021 to 2022 is shown in blue, 2020 to 2021 in green, 2019 to 2020 in orange, 2018 to 2019 in brown, 2017 to 2018 in magenta, and 2012 to 2013 in dashed brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
High-resolution image

Average Arctic sea ice extent for February 2022 was 14.61 million square kilometers (5.64 million square miles), ranking fourteenth lowest in the satellite record. The 2022 extent was 690,000 square kilometers (266,000 square miles) below the 1981 to 2010 average. Through most of February, extent hovered near the interdecile range, roughly at the lowest 10 percent of the measured extents for those days. Regionally, the sea ice extent was near average in the Bering Sea but continued to be well below average in the Sea of Okhotsk. In the Barents Sea, extent was below average, and a narrow open-water area extended north of Novaya Zemlya. Extent also remained below average in the Gulf of St. Lawrence and along the eastern Greenland coast. As is generally the case near the maximum sea ice extent, there are ups and downs in extent associated with storms moving the ice around, melt along the southern ice margins, and subsequent regrowth.

Conditions in context

Figure 2a. This plot shows the departure from average air temperature in the Arctic at the 925 hPa level, in degrees Celsius, for February 2022. Yellows and reds indicate higher than average temperatures; blues and purples indicate lower than average temperatures.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Laboratory
High-resolution image

Figure 2b. This plot shows average sea level pressure in the Arctic in millibars for February 2022. Yellows and reds indicate high air pressure; blues and purples indicate low pressure.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Laboratory
High-resolution image

In February 2022, temperatures at the 925 hPa level (about 2,500 feet above sea level) ranged from 1 to over 8 degrees Celsius (2 to 14 degrees Fahrenheit) above the 1981 to 2010 average along the Eurasian coast and across the central Arctic Ocean (Figure 2a). However, cool conditions prevailed over much of Canada and Baffin Bay; temperatures were generally 2 to 7 degrees Celsius (4 to 13 degrees Fahrenheit) below average. The sea level air pressure pattern in February was marked by strong low pressure centered over the North Atlantic and high pressure over central Asia, acting to drive air northward from Eastern Europe to the central Arctic, consistent with the above average temperatures there (Figure 2b). In North America, low pressure over the North Atlantic, extending over Baffin Bay, drew Arctic air southward over eastern Canada, bringing cool conditions to the area.

February 2022 compared to previous years

Figure 3. Monthly February ice extent for 1979 to 2022 shows a decline of 2.8 percent per decade.

Credit: National Snow and Ice Data Center
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The downward linear trend in February sea ice extent over the 44-year satellite record is 42,500 square kilometers (16,400 square miles) per year, or 2.8 percent per decade relative to the 1981 to 2010 average. Based on the linear trend, since 1979, February has seen a loss of 1.82 million square kilometers (703,000 square miles). This is equivalent to about seven times the area of Oregon.

Antarctic sea ice minimum sets a record

Figure 4a. Before 2022, the previous record low Antarctic sea ice extent was observed on March 3, 2017. This figure shows the difference in sea ice extent from that date (shown in white) compared with the new record low on February 25, 2022 (shown in dark blue). Ice present on both dates is shown in light blue.

Credit: National Snow and Ice Data Center
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Figure 4b. This figure shows the pattern of the 2021 to 2022 Antarctic sea ice decline since the September winter maximum. Each panel shows the sea ice extent for the two dates in the legend, with the earlier date extent in white and the later date extent in light blue.

Credit: National Snow and Ice Data Center
High-resolution image

In the south, Antarctic sea ice recently reached its late-summer minimum, dropping below all previous minimum ice extents in the satellite record (Figure 4a). For the first time since the satellite record began in 1979, extent fell below 2 million square kilometers (772,000 square miles), reaching a minimum extent of 1.92 million square kilometers (741,000 square miles) on February 25. Ice extent declined at a near-average rate through most of the month at about 40,000 square kilometers (15,400 square miles) per day, but the decline significantly slowed to about 15,000 square kilometers (5,800 square miles) per day towards the end of the month.

Following the unusually early and above average sea ice maximum extent on September 1, there was a rapid decline in ice extent through the austral spring and summer, with the most notable feature being the clearing out of ice from the Ross and Amundsen Sea sectors during January and February as well as the loss of ice from the northwestern Weddell Sea region during that period (Figure 4b). Much of the Antarctic coast is still ice-free and sea ice remains well below average in the eastern Ross Sea, western Bellingshausen Sea, and northwestern Weddell Sea. However, persistent patches of high concentration sea ice in the area of Pine Island Bay and in the central Weddell Sea are obstructing research groups trying to work in those areas. The RV Nathaniel B Palmer, operated by the National Science Foundation (NSF), and the RV Araon, operated by South Korea’s Korean Polar Research Institute (KOPRI), have been attempting to conduct research near the outlet of Thwaites Glacier. The research teams were forced to work at an adjacent region to the west, the Dotson Ice Shelf, to avoid the heavy ice conditions near Thwaites.

Ups and downs in the southern ice

Figure 5a. This plot shows the annual Antarctic minimum daily (5-day running average) extent for 1979 to 2022 (black) and the 1979 to 2022 trend line (blue). For the first time since the satellite record began in 1979, sea ice in the Southern Hemisphere fell below 2 million square kilometers (772,000 square miles), reaching a minimum of 1.92 million square kilometers (741,000 square miles) on February 25.

Credit: National Snow and Ice Data Center
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Figure 5b. This plot shows the changes in the trend of seasonal sea ice minimums over the satellite record for Antarctic sea ice, beginning with the trend after ten years and proceeding year-by-year. For much of the satellite monitoring period, the trend has been towards increasing ice, but the vertical bars show that the high variability in the records means that the trend is not statistically significant. As of 2022, the net trend is very close to zero.

Credit: National Snow and Ice Data Center
High-resolution image

The Antarctic sea ice is notable for its variability, both seasonally, losing over 80 percent of its ice cover from its maximum to its annual minimum extent, and from year to year. While 2022 had a record low minimum, the highest minimum in the satellite record was observed as recently as 2015 (Figure 5a). The effect of this large year to year variability on computed trends is evident when plotting how the trend has changed over time (Figure 5b). We calculated the trend for the period of 1979 to 1988, then 1979 to 1989, then 1979 to 1990, and so forth.

The trend is initially positive for the 1979 to 1988 period, but then dips negative for a couple years, then bounces between positive and negative until the year 2001, after which it remained positive through 2021. Also plotted is the 2 standard deviation range of the trend as the vertical “whiskers” for each year; this is a measure of how confident one should be in the trend values. If the 2 standard deviation range for a computed trend crosses the zero line (i.e., encompasses both positive and negative values), it means that the trend value may simply be due to the year-to-year swings in the extent. Phrased differently, it means that the trend does not meet the 95 percent confidence level for statistical significance. So while the trend in minimum extent has been largely positive over the past two decades, it has not been significant except the three-year period, 2014 to 2016. Through 2022, the trend starting in 1979 is ever so slightly negative again: -18 square kilometers (-6.94 square miles) per year. But it is still not a significant trend. Variability in summer continues to rule Antarctic sea ice extent.

Eos recently published an article that summarizes three different modeling studies that attempt to explain the causes of the variability and the (until this year) positive trend in Antarctic sea ice extent. The article finds that while winds and sea surface temperature are important contributors to the growth of Antarctic sea ice over the last 30+ years, there are likely additional factors at play.

Search for the Endurance

Figure 6a. Mrs. Chippy, the resident cat of Endurance, the vessel that carried Ernest Shackleton and his team to Antarctica in 1914, stands on the shoulder of a crewmember. Mrs. Chippy did not survive the expedition.

Credit: Perce Blackborow
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Figure 6b. These images show the stern of the Endurance, the ship used by Ernest Shackleton to reach the Weddell Sea on his ill-fated Imperial Trans-Antarctic Expedition. The ship was found in 3,000 meters (10,000 feet) of water in the northwestern Weddell Sea by a search expedition using uncrewed submersible vehicles.

Credit: Falklands Maritime Heritage Trust and National Geographic.
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In the Weddell Sea, the South African research icebreaker RV Agulhas II has been attempting to find the wreck of the Endurance on the seafloor. The Endurance is the vessel that brought Ernest Shackleton and his team to Antarctica in 1914, only to be blocked by sea ice. The ice later crushed the ship and the team was forced to trek across the sea ice and sail to a small, uninhabited island near the tip of the Antarctic Peninsula. Shackleton and five others then sailed in a lifeboat over 1,600 kilometers (1,000 miles) to South Georgia Island, one of the greatest polar voyages in history, to reach civilization. They then returned in a Chilean ship, the Yelcho, to rescue the rest of the expeditioners on Elephant Island. Miraculously, all of the human crew were successfully rescued. However, several sled dogs and one male cat, Mrs. Chippy, did not survive (Figure 6a).

On March 5, the Endurance was found by undersea drones operating from the South African ice breaker (Figure 6b). This was after just two weeks of searching in the area where the navigator of the 1915 expedition, Frank Worsely, noted its last location. It was found in 3,000 meters (10,000 feet) of water in near-pristine condition because of the absence of wood-boring worms in the Weddell benthic ecosystem. The ship was found just 6 kilometers (4 miles) from the last reported location, made on November 21, 1915, with sextant and chronometer.

Further reading

Alexander, C., and J. Dorman. 2003. The Endurance: Shackleton’s Legendary Antarctic Expedition. Columbia TriStar.

Amos, J. 2022. Endurance: Shackleton’s lost ship is found in Antarctic. BBC. https://www.bbc.com/news/science-environment-60662541

Blanchard-Wrigglesworth, E., I. Eisenman, S. Zhang, S. Sun, and A. Donohoe. 2022. New Perspectives on the Enigma of Expanding Antarctic Sea Ice. Eos.
https://eos.org/science-updates/new-perspectives-on-the-enigma-of-expanding-antarctic-sea-ice

Davidson, L. 2022. The Adventures of Mrs. Chippy, Shackleton’s Seafaring Cat. History Hit. https://www.historyhit.com/mrs-chippy-shackletons-seafaring-cat/

Sir Ernest Shackleton Endurance Expedition Trans-Antarctica 1914-1917 – 1, Departure. Cool Antarctica. https://www.coolantarctica.com/Antarctica%20fact%20file/History/Shackleton-Endurance-Trans-Antarctic_expedition.php

Worsley, F. A. 1998. Shackleton’s boat journey. WW Norton & Company.

Update

When we first published this post, the Endurance had not yet been found. We updated this post on March 9, 2022, to include the information about the discovery of the Endurance. 

While January began with sea ice extent below average, by the end of the month, extent increased. January 2022 finished as the sixteenth lowest extent in the satellite record above all years since 2009. This illustrates the large natural variability in sea ice conditions. However, winter ice extent is a poor indicator of what the ice extent will look like this coming September.

Overview of conditions

Figure 1a. Arctic sea ice extent for January 2022 was 13.88 million square kilometers (5.36 million square miles). The magenta line shows the 1981 to 2010 average extent for that month. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

Figure 1b. The graph above shows Arctic sea ice extent as of February 2, 2022, along with daily ice extent data for four previous years and the record low year. 2021 to 2022 is shown in blue, 2020 to 2021 in green, 2019 to 2020 in orange, 2018 to 2019 in brown, 2017 to 2018 in magenta, and 2012 to 2013 in dashed brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
High-resolution image

Average Arctic sea ice extent for January 2022 was 13.88 million square kilometers (5.36 million square miles), ranking sixteenth lowest in the satellite record (Figure 1a). The 2022 extent was 540,000 square kilometers (208,000 square miles) below the 1981 to 2010 average. Throughout most of January, extent tracked within the interdecile range of the satellite record, falling below the interdecile range on January 26 (Figure 1b). Regionally, the sea ice extent was above average in the Bering Sea, yet below average in the Sea of Okhotsk and the Barents Sea. Extent also remained lower than average in the Gulf of St. Lawrence. At the end of the month, sea ice extent was above all years since 2009.

Conditions in context

Figure 2a. This plot shows the departure from average air temperature in the Arctic at the 925 hPa level, in degrees Celsius, for January 2022. Yellows and reds indicate higher than average temperatures; blues and purples indicate lower than average temperatures.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Laboratory
High-resolution image

Figure 2b. This plot shows the departure from average sea level pressure in the Arctic in millibars for January 2022. Yellows and reds indicate higher than average air pressures; blues and purples indicate lower than average air pressures.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Laboratory
High-resolution image

Air temperatures for January 2022 at the 925 millibar level (about 2,500 feet above the surface) were above average over all of the Arctic Ocean. Temperatures were up to 7 degrees Celsius (13 degrees Fahrenheit) higher than average north of the Canadian Archipelago, with more modest departures in other areas (Figure 2a). The corresponding sea level pressure pattern for January 2022 featured the characteristic Siberian high pressure region that typically forms over eastern Siberia in autumn and winter. However, sea level pressure was up to 8 millibars above average over eastern Siberia, stretching across the Bering Sea and into western Alaska (Figure 2b). This was coupled with below average sea level pressure over Eurasia and Hudson Bay. Generally, when the Siberian High is strong, advection of warm air from eastern Europe leads to mild conditions over the Kara and Laptev Seas. The high over Siberia was also complemented by low pressure south of the Aleutians. This pattern led to winds bringing cold air that enhanced freezing in the Bering Sea and pushed ice southward, leading to the higher extent in the Bering Sea.

January 2022 compared to previous years

Figure 3. Monthly January ice extent for 1979 to 2022 shows a decline of 3.0 percent per decade.

Credit: National Snow and Ice Data Center
High-resolution image

The downward linear trend in January sea ice extent over the 44-year satellite record is 42,800 square kilometers (16,500 square miles) per year, or 3.0 percent per decade relative to the 1981 to 2010 average. Based on the linear trend, since 1979, January has seen a loss of 1.86 million square kilometers (718,000 square miles). This is equivalent to about four times the area of California.

Role of North Atlantic Heat Transport on Barents Sea ice

Figure 4a. The left map of the Arctic Ocean shows the simulated average transport of water volume in Sverdrups (Sv: equal to one million cubic meters per second, or about 260 million gallons per second). The right map show the heat loss in terawatts (TW; equal to one trillion watts) for individual regions. The values shown are average annual values for 1900 to 2000.

Credit: Smedsrud et al. 2022
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Figure 4b. Annual ocean temperatures averaged between 50 and 200 meters (164 and 656 feet) depth from 1977 through 2020 showing the variation of ocean heat in the western Barents Sea.

Credit: Institute of Marine Research, Norway
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The northward flow of warm Atlantic Water along the coast of Norway is a primary oceanic heat source for the Arctic Ocean (Figure 4a). During periods when there is increased transport of Atlantic Water, there is reduced winter sea ice in northern Barents Sea and increased ocean heat loss, leading to denser water. The northward flow of Atlantic water towards the Arctic has been high in recent decades. According to colleagues at the Geophysical Institute in Bergen, Norway, the oceanic heat transport to the Arctic Ocean is 30 percent higher today than it was around 1900.  However, over a shorter time-frame, there is no distinct trend in warm water flow between 1995 and 2020. The total annual transport of ocean heat, a combination of water volume and the temperature of that water, started to decrease after 2015 (Figure 4b). However, while the volume of Atlantic Water through the Barents Sea opening started to drop in 2015, northern Norway experienced several strong storms from the south, that may have broken up the ice cover or kept it from advancing southward. The wind-driven changes in northward movement of Atlantic Water is likely a result of natural climate variability, including both upstream ocean circulation changes and large-scale atmospheric circulation patterns such as the Arctic Oscillation; however, some researchers think that sea ice loss in the Arctic may also be affecting wind patterns.

Antarctic sea ice taking the plunge

Figure 5a. The graph above shows Antarctic sea ice extent as of February 2, 2022, along with daily ice extent data for five previous years. 2021 to 2022 is shown in blue, 2020 to 2021 in green, 2019 to 2020 in orange, 2018 to 2019 in brown, 2017 to 2018 in magenta, and 2013 to 2014 in dashed brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
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Figure 5b. These graphs show Antarctic sea ice extent in square kilometers in five different regions as well as Antarctica’s overall sea ice extent.

Credit: Robbie Mallet, University College London
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During the southern hemisphere spring in 2016, Antarctic sea ice suddenly shrank, leading to a series of months (extending into the 2016 to 2017 austral summer) with the lowest monthly average extents in the satellite data record. This January, Antarctic sea ice was the second lowest ice extent in the 44-year record (Figure 5a). Regionally, ice extent is tracking below levels observed for 2017 in the Indian and Pacific sectors, but above levels for that year in other sectors (Figure 5b). In 2017, only the Ross Sea region had record low extent, so it was the driver of the overall record low hemispheric extent. Similarly, this year none of the individual regions have record low extents, but all are well below average leading to the second lowest Antarctic sea ice in the satellite record, above 2017.

The more moderate extent levels since the record lows in 2016 to 2017 result in a small, not statistically significant (at the 95 percent level) positive trend. Climate models simulating the response to anthropogenic greenhouse gas emissions suggest that Antarctic sea ice should be decreasing. So there is a seeming contradiction between the observations and the models. One possibility is that natural variability is higher than the models indicate and that natural variability may still dominate the Antarctic sea ice trends. A new study led by R. Fogt looked at an ensemble of reconstructions of Antarctic sea ice extent since 1905 using sea level pressure, air temperatures, and indices of climate variability. This study argues that the seasonally observed positive trends since 1979 are unusual over the twentieth century, and that a shift occurred around 1960, before routine satellite observations began. This hints that there is indeed pronounced decadal scale variability in ocean and atmospheric conditions that influence Antarctic sea ice. Whether the low ice conditions of recent years represent a new decadal-scale shift remains to be seen.

References

Årthun, M., T. Eldevik, and L. H. Smedsrud. 2019. The Role of Atlantic Heat Transport in Future Arctic Winter Sea Ice Loss, Journal of Climate, 32(11), 3327-3341. Retrieved Feb 3, 2022, from https://journals.ametsoc.org/view/journals/clim/32/11/jcli-d-18-0750.1.xml.

Fogt, R.L., A. M. Sleinkofer, M. N. Raphael, et al. 2022. A regime shift in seasonal total Antarctic sea ice extent in the twentieth century. Nature Climate Chang. 12, 54–62. doi:10.1038/s41558-021-01254-9.

Helland-Hansen, B. and F. Nansen. 1909. The Norwegian Sea: Its physical oceanography based upon the Norwegian researches 1900–1904. Det Mallingske bogtrykkeri.

Orvik, K. A. 2022. Long-term moored current and temperature measurements of the Atlantic inflow into the Nordic Seas in the Norwegian Atlantic Current; 1995-2020. Geophysical Research Letters, 49, e2021GL096427. doi:10.1029/2021GL096427

Smedsrud, L. H., M. Muilwijk, A. Brakstad, E. Madonna, S. K. Lauvset, C. Spensberger, C., et al. 2022. Nordic Seas heat loss, Atlantic inflow, and Arctic sea ice cover over the last century. Reviews of Geophysics, 60, e2020RG000725. doi:10.1029/2020RG000725.

Erratum

On February 9, 2022, a user informed the ASINA team of an error in the text, which stated, “January 2022 finished as the sixteenth lowest extent in the satellite record above all years since 2009, with the exception of 2013 and 2014.” The correct text should state that “January 2022 finished as the sixteenth lowest extent in the satellite record above all years since 2009.” The correction has been made.

By early January 2022, Arctic sea ice extent, while well below average, was within the lowest decile of recorded extents of the 1981 to 2010 reference period. Sea ice now completely covers Hudson Bay; the only area with substantially below average extent is in southern Baffin Bay and north of Labrador.

Overview of conditions

Figure 1. Arctic sea ice extent for December 2021 was 12.19 million square kilometers (4.71 million square miles). The magenta line shows the 1981 to 2010 average extent for that month. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
High-resolution image

Average Arctic sea ice extent for December 2021 was 12.19 million square kilometers (4.71 million square miles), which ranked thirteenth lowest in the satellite record. The 2021 extent was 650,000 square kilometers (251,000 square miles) below the 1981 to 2010 average. As of early January 2022, sea ice completely covers Hudson Bay. The only area with extent remarkably below normal is southern Baffin Bay and off the coast of Labrador, where the December sea ice extent ranked fourth lowest.

Conditions in context

Figure 2a. The graph above shows Arctic sea ice extent as of January 4, 2022, along with daily ice extent data for four previous years and the record low year. 2021 to 2022 is shown in blue, 2020 to 2021 in green, 2019 to 2020 in orange, 2018 to 2019 in brown, 2017 to 2018 in magenta, and 2012 to 2013 in dashed brown. The 1981 to 2010 median is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data. Sea Ice Index data.

Credit: National Snow and Ice Data Center
High-resolution image

Figure 2b. This plot shows the departure from average air temperature in the Arctic at the 925 hPa level, in degrees Celsius, for December 2021. Yellows and reds indicate higher than average temperatures; blues and purples indicate lower than average temperatures.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Laboratory
High-resolution image

Figure 2c. This plot shows average sea level pressure in the Arctic in millibars for December 2021. Yellows and reds indicate high air pressure; blues and purples indicate low pressure.

Credit: NSIDC courtesy NOAA Earth System Research Laboratory Physical Sciences Laboratory
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The air temperature pattern averaged for December 2021 at the 925 millibar level (about 2,500 feet above the surface) was characterized by above average temperatures. Temperatures were up to 6 degrees Celsius (11 degrees Fahrenheit) above average over Greenland, north of the Canadian Arctic Archipelago, and the East Greenland Sea. Three areas of below average temperatures were found over western and eastern Eurasia and northwestern Canada (Figure 2b). The corresponding sea level pressure pattern for December 2021 featured fairly low pressures (less than 1,015 millibars) encompassing essentially all of the Arctic except for the Laptev Sea region (Figure 2c). These pressures were nevertheless not substantially unusual compared to average—at most 6 to 7 millibars below average. The notable exception is south of the Aleutian Islands, where the sea level pressure was up to 24 millibars above average.

December 2021 compared to previous years

Figure 3. Monthly December ice extent for 1979 to 2021 shows a decline of 3.5 percent per decade.

Credit: National Snow and Ice Data Center
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The downward linear trend in December sea ice extent over the 43-year satellite record is 45,000 square kilometers (17,400 square miles) per year, or 3.5 percent per decade relative to the 1981 to 2010 average. Based on the linear trend, since 1979, December has seen a loss of 1.88 million square kilometers (726,000 square miles). This is equivalent to about three times the size of Texas.

Hudson Bay ices over

Figure 4. This NASA Worldview image shows the last part of  Hudson Bay freezing up along the southeast coast as of December 23, 2021. After a late freeze up, Hudson Bay is completely ice covered as of early January 2022.

Credit: NASA
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In our previous post, we noted that by the end of November, the northern half of Hudson Bay is usually completely iced over. As of the end of November 2021, only the far north was frozen over; the rest of the bay was ice free except for a narrow band of ice along the western coastline. However, as lower temperatures kicked in and the upper ocean lost the heat that it had gained in summer, the entire bay subsequently froze over. The ice cover is now complete.

Antarctic notes

Figure 5. Antarctic sea ice extent for December 2021 was 9.2 million square kilometers (3.55 million square miles). The magenta line shows the 1981 to 2010 average extent for that month. Sea Ice Index data. About the data

Credit: National Snow and Ice Data Center
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Antarctic sea ice extent for December 2021 was low overall, tracking at similar extents seen in 2017. Regionally, extent was particularly low in the Weddell Sea and southern Ross Sea regions. Several large polynyas formed in the eastern Weddell Sea; the Maud Rise Polynya opened in late November and then spread east to northeast. This is unusual; normally, the polynya extends south and west of its initiation point. The Southern Annular Mode (SAM) was in a strong positive phase through the first half of the month, indicating strong westerly winds and a strong low-pressure area in the Amundsen Sea. Sea ice conditions are not yet favorable for two planned cruises near Thwaites Glacier, one by the US Antarctic research program (RV Nathaniel B. Palmer) and the other by the South Korean (RV Araon). Ships are due to arrive in late January.

Killer whales in the Arctic

Bowhead whales have played an integral role in the cultural and subsistence life of Inuit communities for millennia. New research at the University of Washington analyzing acoustic data has found that the loss of sea ice has allowed killer whales, also known as Orcas, to venture into waters that were once inaccessible to them. The expanding range of killer whales, a top predator, has potential ramification for the Arctic food web and especially bowhead whales. Indigenous Arctic communities have noted an increased number of carcasses of bowhead whales in the Chukchi and Beaufort seas that were preyed upon by Orcas. Normally, bowheads can avoid predation by retreating into protective areas of heavy sea ice that the smaller Orcas cannot break through to breathe. If the bowheads must spend more time in thick ice, this can be a problem because feeding opportunities are more limited. Calves that cannot break through the ice may also drown.