Cryosphere

Overview of the cryosphere and its larger components[1]

The cryosphere (from the Greek κρύος kryos, "cold", "frost" or "ice" and σφαῖρα sphaira, "globe, ball"[2]) is an all-encompassing term for the portions of Earth's surface where water is in solid form, including sea ice, lake ice, river ice, snow cover, glaciers, ice caps, ice sheets, and frozen ground (which includes permafrost). Thus, there is a wide overlap with the hydrosphere. The cryosphere is an integral part of the global climate system with important linkages and feedbacks generated through its influence on surface energy and moisture fluxes, clouds, precipitation, hydrology, atmospheric and oceanic circulation.

Through these feedback processes, the cryosphere plays a significant role in the global climate and in climate model response to global changes. Approximately 10% of the Earth's surface is covered by ice, but this is rapidly decreasing.[3] The term deglaciation describes the retreat of cryospheric features.

Overall interactions[edit]

The cryosphere is one of five components of the climate system. The others are the atmosphere, the hydrosphere, the lithosphere and the biosphere.[4]: 1451 

Frozen water is found on the Earth’s surface primarily as snow cover, freshwater ice in lakes and rivers, sea ice, glaciers, ice sheets, and frozen ground and permafrost (permanently frozen ground). The residence time of water in each of these cryospheric sub-systems varies widely. Snow cover and freshwater ice are essentially seasonal, and most sea ice, except for ice in the central Arctic, lasts only a few years if it is not seasonal. A given water particle in glaciers, ice sheets, or ground ice, however, may remain frozen for 10–100,000 years or longer, and deep ice in parts of East Antarctica may have an age approaching 1 million years.[citation needed]

Most of the world's ice volume is in Antarctica, principally in the East Antarctic Ice Sheet. In terms of areal extent, however, Northern Hemisphere winter snow and ice extent comprise the largest area, amounting to an average 23% of hemispheric surface area in January. The large areal extent and the important climatic roles of snow and ice, related to their unique physical properties, indicate that the ability to observe and model snow and ice-cover extent, thickness, and physical properties (radiative and thermal properties) is of particular significance for climate research.[citation needed]

There are several fundamental physical properties of snow and ice that modulate energy exchanges between the surface and the atmosphere. The most important properties are the surface reflectance (albedo), the ability to transfer heat (thermal diffusivity), and the ability to change state (latent heat). These physical properties, together with surface roughness, emissivity, and dielectric characteristics, have important implications for observing snow and ice from space. For example, surface roughness is often the dominant factor determining the strength of radar backscatter.[5] Physical properties such as crystal structure, density, length, and liquid water content are important factors affecting the transfers of heat and water and the scattering of microwave energy.

The surface reflectance of incoming solar radiation is important for the surface energy balance (SEB). It is the ratio of reflected to incident solar radiation, commonly referred to as albedo. Climatologists are primarily interested in albedo integrated over the shortwave portion of the electromagnetic spectrum (~300 to 3500 nm), which coincides with the main solar energy input. Typically, albedo values for non-melting snow-covered surfaces are high (~80–90%) except in the case of forests.[citation needed] The higher albedos for snow and ice cause rapid shifts in surface reflectivity in autumn and spring in high latitudes, but the overall climatic significance of this increase is spatially and temporally modulated by cloud cover. (Planetary albedo is determined principally by cloud cover, and by the small amount of total solar radiation received in high latitudes during winter months.) Summer and autumn are times of high-average cloudiness over the Arctic Ocean so the albedo feedback associated with the large seasonal changes in sea-ice extent is greatly reduced. It was found that snow cover exhibited the greatest influence on Earth's radiative balance in the spring (April to May) period when incoming solar radiation was greatest over snow-covered areas.[6]

The thermal properties of cryospheric elements also have important climatic consequences.[citation needed] Snow and ice have much lower thermal diffusivities than air. Thermal diffusivity is a measure of the speed at which temperature waves can penetrate a substance. Snow and ice are many orders of magnitude less efficient at diffusing heat than air. Snow cover insulates the ground surface, and sea ice insulates the underlying ocean, decoupling the surface-atmosphere interface with respect to both heat and moisture fluxes. The flux of moisture from a water surface is eliminated by even a thin skin of ice, whereas the flux of heat through thin ice continues to be substantial until it attains a thickness in excess of 30 to 40 cm. However, even a small amount of snow on top of the ice will dramatically reduce the heat flux and slow down the rate of ice growth. The insulating effect of snow also has major implications for the hydrological cycle. In non-permafrost regions, the insulating effect of snow is such that only near-surface ground freezes and deep-water drainage is uninterrupted.[7]

While snow and ice act to insulate the surface from large energy losses in winter, they also act to retard warming in the spring and summer because of the large amount of energy required to melt ice (the latent heat of fusion, 3.34 x 105 J/kg at 0 °C). However, the strong static stability of the atmosphere over areas of extensive snow or ice tends to confine the immediate cooling effect to a relatively shallow layer, so that associated atmospheric anomalies are usually short-lived and local to regional in scale.[8] In some areas of the world such as Eurasia, however, the cooling associated with a heavy snowpack and moist spring soils is known to play a role in modulating the summer monsoon circulation.[9]

Climate change feedback mechanisms[edit]

There are numerous cryosphere-climate feedbacks in the global climate system. These operate over a wide range of spatial and temporal scales from local seasonal cooling of air temperatures to hemispheric-scale variations in ice sheets over time scales of thousands of years. The feedback mechanisms involved are often complex and incompletely understood. For example, Curry et al. (1995) showed that the so-called "simple" sea ice-albedo feedback involved complex interactions with lead fraction, melt ponds, ice thickness, snow cover, and sea-ice extent.[citation needed]

The role of snow cover in modulating the monsoon is just one example of a short-term cryosphere-climate feedback involving the land surface and the atmosphere.[9][citation needed]

Components[edit]

Glaciers and ice sheets[edit]

Representation of glaciers on a topographic map
The Taschachferner glacier in the Ötztal Alps in Austria. The mountain to the left is the Wildspitze (3.768 m), second highest in Austria. To the right is an area with open crevasses where the glacier flows over a kind of large cliff.[10]

Ice sheets and glaciers are flowing ice masses that rest on solid land. They are controlled by snow accumulation, surface and basal melt, calving into surrounding oceans or lakes and internal dynamics. The latter results from gravity-driven creep flow ("glacial flow") within the ice body and sliding on the underlying land, which leads to thinning and horizontal spreading.[11] Any imbalance of this dynamic equilibrium between mass gain, loss and transport due to flow results in either growing or shrinking ice bodies.

Aerial view of the ice sheet on Greenland's east coast

Relationships between global climate and changes in ice extent are complex. The mass balance of land-based glaciers and ice sheets is determined by the accumulation of snow, mostly in winter, and warm-season ablation due primarily to net radiation and turbulent heat fluxes to melting ice and snow from warm-air advection[12][13] Where ice masses terminate in the ocean, iceberg calving is the major contributor to mass loss. In this situation, the ice margin may extend out into deep water as a floating ice shelf, such as that in the Ross Sea.

A glacier (US: /ˈɡlʃər/; UK: /ˈɡlæsiər, ˈɡlsiər/) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as crevasses and seracs, as it slowly flows and deforms under stresses induced by its weight. As it moves, it abrades rock and debris from its substrate to create landforms such as cirques, moraines, or fjords. Although a glacier may flow into a body of water, it forms only on land and is distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water.

On Earth, 99% of glacial ice is contained within vast ice sheets (also known as "continental glaciers") in the polar regions, but glaciers may be found in mountain ranges on every continent other than the Australian mainland, including Oceania's high-latitude oceanic island countries such as New Zealand. Between latitudes 35°N and 35°S, glaciers occur only in the Himalayas, Andes, and a few high mountains in East Africa, Mexico, New Guinea and on Zard-Kuh in Iran.[14] With more than 7,000 known glaciers, Pakistan has more glacial ice than any other country outside the polar regions.[15][16] Glaciers cover about 10% of Earth's land surface. Continental glaciers cover nearly 13 million km2 (5 million sq mi) or about 98% of Antarctica's 13.2 million km2 (5.1 million sq mi), with an average thickness of ice 2,100 m (7,000 ft). Greenland and Patagonia also have huge expanses of continental glaciers.[17] The volume of glaciers, not including the ice sheets of Antarctica and Greenland, has been estimated at 170,000 km3.[18]

Glacial ice is the largest reservoir of fresh water on Earth, holding with ice sheets about 69 percent of the world's freshwater.[19][20] Many glaciers from temperate, alpine and seasonal polar climates store water as ice during the colder seasons and release it later in the form of meltwater as warmer summer temperatures cause the glacier to melt, creating a water source that is especially important for plants, animals and human uses when other sources may be scant. However, within high-altitude and Antarctic environments, the seasonal temperature difference is often not sufficient to release meltwater.

In glaciology, an ice sheet, also known as a continental glacier,[21] is a mass of glacial ice that covers surrounding terrain and is greater than 50,000 km2 (19,000 sq mi).[22] The only current ice sheets are the Antarctic ice sheet and the Greenland ice sheet. Ice sheets are bigger than ice shelves or alpine glaciers. Masses of ice covering less than 50,000 km2 are termed an ice cap. An ice cap will typically feed a series of glaciers around its periphery.

Although the surface is cold, the base of an ice sheet is generally warmer due to geothermal heat. In places, melting occurs and the melt-water lubricates the ice sheet so that it flows more rapidly. This process produces fast-flowing channels in the ice sheet — these are ice streams.

In previous geologic time spans (glacial periods) there were other ice sheets: during the Last Glacial Period at Last Glacial Maximum, the Laurentide Ice Sheet covered much of North America, the Weichselian ice sheet covered Northern Europe and the Patagonian Ice Sheet covered southern South America.

Sea ice[edit]

Broken pieces of Arctic sea ice with a snow cover
Satellite image of sea ice forming near St. Matthew Island in the Bering Sea

Sea ice covers much of the polar oceans and forms by freezing of sea water. Satellite data since the early 1970s reveal considerable seasonal, regional, and interannual variability in the sea ice covers of both hemispheres. Seasonally, sea-ice extent in the Southern Hemisphere varies by a factor of 5, from a minimum of 3–4 million km2 in February to a maximum of 17–20 million km2 in September.[23][24] The seasonal variation is much less in the Northern Hemisphere where the confined nature and high latitudes of the Arctic Ocean result in a much larger perennial ice cover, and the surrounding land limits the equatorward extent of wintertime ice. Thus, the seasonal variability in Northern Hemisphere ice extent varies by only a factor of 2, from a minimum of 7–9 million km2 in September to a maximum of 14–16 million km2 in March.[24][25]

The ice cover exhibits much greater regional-scale interannual variability than it does hemispherical. For instance, in the region of the Sea of Okhotsk and Japan, maximum ice extent decreased from 1.3 million km2 in 1983 to 0.85 million km2 in 1984, a decrease of 35%, before rebounding the following year to 1.2 million km2.[24] The regional fluctuations in both hemispheres are such that for any several-year period of the satellite record some regions exhibit decreasing ice coverage while others exhibit increasing ice cover.[26]

Frozen ground and permafrost[edit]

Map showing extent and types of permafrost in the Northern Hemisphere

Permafrost (from perma- 'permanent', and frost) is soil or underwater sediment which continuously remains below 0 °C (32 °F) for two years or more: the oldest permafrost had been continuously frozen for around 700,000 years.[27] While the shallowest permafrost has a vertical extent of below a meter (3 ft), the deepest is greater than 1,500 m (4,900 ft).[28] Similarly, the area of individual permafrost zones may be limited to narrow mountain summits or extend across vast Arctic regions.[29] The ground beneath glaciers and ice sheets is not usually defined as permafrost, so on land, permafrost is generally located beneath a so-called active layer of soil which freezes and thaws depending on the season.[30]

Around 15% of the Northern Hemisphere or 11% of the global surface is underlain by permafrost,[31] with the total area of around 18 million km2 (6.9 million sq mi).[32] This includes substantial areas of Alaska, Greenland, Canada, and Siberia. It is also located in high mountain regions, with the Tibetan Plateau a prominent example. Only a minority of permafrost exists in the Southern Hemisphere, where it is consigned to mountain slopes like in the Andes of Patagonia, the Southern Alps of New Zealand, or the highest mountains of Antarctica.[29][27]

Permafrost contains large amounts of dead biomass that have accumulated throughout millennia without having had the chance to fully decompose and release their carbon, making tundra soil a carbon sink.[29] As global warming heats the ecosystem, frozen soil thaws and becomes warm enough for decomposition to start anew, accelerating the permafrost carbon cycle. Depending on conditions at the time of thaw, decomposition can either release carbon dioxide or methane, and these greenhouse gas emissions act as a climate change feedback.[33][34][35] The emissions from thawing permafrost will have a sufficient impact on the climate to impact global carbon budgets. Exact estimates of permafrost emissions are hard to model because of the uncertainty about different thaw processes. There is a widespread agreement they will be smaller than human-caused emissions and not large enough to result in "runaway warming".[36] Instead, projected annual permafrost emissions have been compared to global emissions from deforestation, or to annual emissions of large countries such as Russia, the United States or China.[37]

Snow cover[edit]

Snow-covered trees in Kuusamo, Finland
Snow drifts forming around downwind obstructions

Most of the Earth's snow-covered area is located in the Northern Hemisphere, and varies seasonally from 46.5 million km2 in January to 3.8 million km2 in August.[38]

Snow cover is an extremely important storage component in the water balance, especially seasonal snowpacks in mountainous areas of the world. Though limited in extent, seasonal snowpacks in the Earth’s mountain ranges account for the major source of the runoff for stream flow and groundwater recharge over wide areas of the midlatitudes. For example, over 85% of the annual runoff from the Colorado River basin originates as snowmelt. Snowmelt runoff from the Earth's mountains fills the rivers and recharges the aquifers that over a billion people depend on for their water resources.[citation needed]

Furthermore, over 40% of the world's protected areas are in mountains, attesting to their value both as unique ecosystems needing protection and as recreation areas for humans.[citation needed]

Lake ice and river ice[edit]

Ice forms on rivers and lakes in response to seasonal cooling. The sizes of the ice bodies involved are too small to exert anything other than localized climatic effects. However, the freeze-up/break-up processes respond to large-scale and local weather factors, such that considerable interannual variability exists in the dates of appearance and disappearance of the ice. Long series of lake-ice observations can serve as a proxy climate record, and the monitoring of freeze-up and break-up trends may provide a convenient integrated and seasonally-specific index of climatic perturbations. Information on river-ice conditions is less useful as a climatic proxy because ice formation is strongly dependent on river-flow regime, which is affected by precipitation, snow melt, and watershed runoff as well as being subject to human interference that directly modifies channel flow, or that indirectly affects the runoff via land-use practices.[citation needed]

Lake freeze-up depends on the heat storage in the lake and therefore on its depth, the rate and temperature of any inflow, and water-air energy fluxes. Information on lake depth is often unavailable, although some indication of the depth of shallow lakes in the Arctic can be obtained from airborne radar imagery during late winter (Sellman et al. 1975) and spaceborne optical imagery during summer (Duguay and Lafleur 1997). The timing of breakup is modified by snow depth on the ice as well as by ice thickness and freshwater inflow.[citation needed]

Declines caused by climate change[edit]

Earth lost 28 trillion tonnes of ice between 1994 and 2017, with melting grounded ice (ice sheets and glaciers) raising the global sea level by 34.6 ±3.1 mm.[39] The rate of ice loss has risen by 57% since the 1990s−from 0.8 to 1.2 trillion tonnes per year.[39]
Melting of glacial mass is approximately linearly related to temperature rise.[40]
Shrinkage of snow cover duration in the Alps, starting ca. end of the 19th century, highlighting climate change adaptation needs[41]
The cryosphere, the area of the Earth covered by snow or ice, is extremely sensitive to changes in global climate.[42] There has been an extensive loss of snow on land since 1981. Some of the largest declines have been observed in the spring.[43] During the 21st century, snow cover is projected to continue its retreat in almost all regions.[44]: 39–69 

Ice sheet melt[edit]

2023 projections of how much the Greenland ice sheet may shrink from its present extent by the year 2300 under the worst possible climate change scenario (upper half) and of how much faster its remaining ice will be flowing in that case (lower half)[45]
Potential equilibrium states of the ice sheet in response to different equilibrium carbon dioxide concentrations in parts per million. Second and third states would result in 1.8 m (6 ft) and 2.4 m (8 ft) of sea level rise, while the fourth state is equivalent to 6.9 m (23 ft).[46][47]

The Greenland ice sheet is an ice sheet which forms the second largest body of ice in the world. It is an average of 1.67 km (1.0 mi) thick, and over 3 km (1.9 mi) thick at its maximum.[48] It is almost 2,900 kilometres (1,800 mi) long in a north–south direction, with a maximum width of 1,100 kilometres (680 mi) at a latitude of 77°N, near its northern edge.[49] The ice sheet covers 1,710,000 square kilometres (660,000 sq mi), around 80% of the surface of Greenland, or about 12% of the area of the Antarctic ice sheet.[48] The term 'Greenland ice sheet' is often shortened to GIS or GrIS in the scientific literature.[50][51][52][53]

A narrated tour about Greenland's ice sheet.
If all 2,900,000 cubic kilometres (696,000 cu mi) of the ice sheet were to melt, it would increase global sea levels by ~7.4 m (24 ft).[48] Global warming between 1.7 °C (3.1 °F) and 2.3 °C (4.1 °F) would likely make this melting inevitable.[53] However, 1.5 °C (2.7 °F) would still cause ice loss equivalent to 1.4 m (4+12 ft) of sea level rise,[54] and more ice will be lost if the temperatures exceed that level before declining.[53] If global temperatures continue to rise, the ice sheet may disappear within 1,000[55] to 10,000 years.[56][57]
The West Antarctic ice sheet is likely to melt completely,[58][59][60]unless temperatures are reduced by 2 °C (3.6 °F) below the levels of the year 2020.[61] The loss of this ice sheet would take between 2,000 and 13,000 years,[62][63] although several centuries of high emissions could shorten this timeframe to 500 years.[64] A sea-level rise of 3.3 m (10 ft 10 in) would occur if the ice sheet collapses leaving ice caps on the mountains and 4.3 m (14 ft 1 in) if those ice caps also melt.[65] Isostatic rebound may contribute an additional 1 m (3 ft 3 in) to global sea levels over another 1,000 years.[64] In contrast, the East Antarctic ice sheet is far more stable and may only cause a sea-level rise of 0.5 m (1 ft 8 in) - 0.9 m (2 ft 11 in) from the current level of warming, a small fraction of the 53.3 m (175 ft) contained in the full ice sheet.[66] With a global warming of around 3 °C (5.4 °F), vulnerable areas like the Wilkes Basin and Aurora Basin may collapse over a period of around 2,000 years,[62][63] potentially adding up to 6.4 m (21 ft 0 in) to sea levels.[64] The complete melting of the East Antarctic ice sheet, which would result in a global warming scenario between 5 °C (9.0 °F) and 10 °C (18 °F), would require at least 10,000 years to disappear.[62][63]


Glaciers decline[edit]

Example of a glacier retreat: White Chuck Glacier, Washington
Glacier in Glacier Peak Wilderness, 1973
White Chuck Glacier in the United States in 1973
White Chuck Glacier in 2006; the glacier has retreated 1.9 kilometres (1.2 mi).
Same vantage point in 2006. The glacier retreated 1.9 kilometres (1.2 mi) in 33 years.

The retreat of glaciers since 1850 is well documented and is one of the effects of climate change. The retreat of mountain glaciers, notably in western North America, Asia, the Alps and tropical and subtropical regions of South America, Africa and Indonesia, provide evidence for the rise in global temperatures since the late 19th century. The acceleration of the rate of retreat since 1995 of key outlet glaciers of the Greenland and West Antarctic ice sheets may foreshadow a rise in sea level, which would affect coastal regions. Excluding peripheral glaciers of ice sheets, the total cumulated global glacial losses over the 26-year period from 1993 to 2018 were likely 5500 gigatons, or 210 gigatons per yr.[67]: 1275 

Deglaciation occurs naturally at the end of ice ages, but glaciologists find the current glacier retreat is accelerated by the measured increase of atmospheric greenhouse gases and is thus effect of climate change. Glacier mass balance is the key determinant of the health of a glacier. If the amount of frozen precipitation in the accumulation zone exceeds the quantity of glacial ice lost due to melting or in the ablation zone a glacier will advance; if the accumulation is less than the ablation, the glacier will retreat. Glaciers in retreat will have negative mass balances, and if they do not find an equilibrium between accumulation and ablation, will eventually disappear.

Sea ice decline[edit]

Reporting the reduction in Antarctic sea ice extent in mid 2023, researchers concluded that a "regime shift" may be taking place "in which previously important relationships no longer dominate sea ice variability".[68]

Sea ice reflects 50% to 70% of the incoming solar radiation back into space. Only 6% of incoming solar energy is reflected by the ocean.[69] As the climate warms, the area covered by snow or sea ice decreases. After sea ice melts, more energy is absorbed by the ocean, so it warms up. This ice-albedo feedback is a self-reinforcing feedback of climate change.[70] Large-scale measurements of sea ice have only been possible since satellites came into use.[71]

Sea ice in the Arctic has declined in recent decades in area and volume due to climate change. It has been melting more in summer than it refreezes in winter. The decline of sea ice in the Arctic has been accelerating during the early twenty-first century. It has a rate of decline of 4.7% per decade. It has declined over 50% since the first satellite records.[72][73][74] Ice-free summers are expected to be rare at 1.5 °C (2.7 °F) degrees of warming. They are set to occur at least once every decade with a warming level of 2 °C (3.6 °F).[75]: 8  The Arctic will likely become ice-free at the end of some summers before 2050.[76]: 9 

Sea ice extent in Antarctica varies a lot year by year. This makes it difficult to determine a trend, and record highs and record lows have been observed between 2013 and 2023. The general trend since 1979, the start of the satellite measurements, has been roughly flat. Between 2015 and 2023, there has been a decline in sea ice, but due to the high variability, this does not correspond to a significant trend.[77]

Permafrost thaw[edit]

Recently thawed Arctic permafrost and coastal erosion on the Beaufort Sea, Arctic Ocean, near Point Lonely, Alaska in 2013.

Globally, permafrost warmed by about 0.3 °C (0.54 °F) between 2007 and 2016, with stronger warming observed in the continuous permafrost zone relative to the discontinuous zone. Observed warming was up to 3 °C (5.4 °F) in parts of Northern Alaska (early 1980s to mid-2000s) and up to 2 °C (3.6 °F) in parts of the Russian European North (1970–2020). This warming inevitably causes permafrost to thaw: active layer thickness has increased in the European and Russian Arctic across the 21st century and at high elevation areas in Europe and Asia since the 1990s.[78]: 1237  Between 2000 and 2018, the average active layer thickness had increased from ~127 centimetres (4.17 ft) to ~145 centimetres (4.76 ft), at an average annual rate of ~0.65 centimetres (0.26 in).[79] In Yukon, the zone of continuous permafrost might have moved 100 kilometres (62 mi) poleward since 1899, but accurate records only go back 30 years. The extent of subsea permafrost is decreasing as well; as of 2019, ~97% of permafrost under Arctic ice shelves is becoming warmer and thinner.[80][36]: 1281  Based on high agreement across model projections, fundamental process understanding, and paleoclimate evidence, it is virtually certain that permafrost extent and volume will continue to shrink as the global climate warms, with the extent of the losses determined by the magnitude of warming.[78]: 1283 

Permafrost thaw is associated with a wide range of issues, and International Permafrost Association (IPA) exists to help address them. It convenes International Permafrost Conferences and maintains Global Terrestrial Network for Permafrost, which undertakes special projects such as preparing databases, maps, bibliographies, and glossaries, and coordinates international field programmes and networks.[81]

Snow cover decrease[edit]

Studies in 2021 found that Northern Hemisphere snow cover has been decreasing since 1978, along with snow depth.[82] Paleoclimate observations show that such changes are unprecedented over the last millennia in Western North America.[83][84][82]

North American winter snow cover increased during the 20th century,[85][86] largely in response to an increase in precipitation.[87]

Because of its close relationship with hemispheric air temperature, snow cover is an important indicator of climate change.[citation needed]

Global warming is expected to result in major changes to the partitioning of snow and rainfall, and to the timing of snowmelt, which will have important implications for water use and management.[citation needed] These changes also involve potentially important decadal and longer time-scale feedbacks to the climate system through temporal and spatial changes in soil moisture and runoff to the oceans.(Walsh 1995). Freshwater fluxes from the snow cover into the marine environment may be important, as the total flux is probably of the same magnitude as desalinated ridging and rubble areas of sea ice.[88] In addition, there is an associated pulse of precipitated pollutants which accumulate over the Arctic winter in snowfall and are released into the ocean upon ablation of the sea ice.[citation needed]

Related scientific disciplines[edit]

"Cryospheric sciences" is an umbrella term for the study of the cryosphere. As an interdisciplinary Earth science, many disciplines contribute to it, most notably geology, hydrology, and meteorology and climatology; in this sense, it is comparable to glaciology.

The term deglaciation describes the retreat of cryospheric features.

See also[edit]

References[edit]

  1. ^ "Cryosphere - Maps and Graphics at UNEP/GRID-Arendal". 2007-08-26. Archived from the original on 2007-08-26. Retrieved 2023-09-25.
  2. ^ σφαῖρα Archived 2017-05-10 at the Wayback Machine, Henry George Liddell, Robert Scott, A Greek-English Lexicon, on Perseus
  3. ^ "Global Ice Viewer – Climate Change: Vital Signs of the Planet". climate.nasa.gov. Retrieved 27 November 2021.
  4. ^ Planton, S. (2013). "Annex III: Glossary" (PDF). In Stocker, T.F.; Qin, D.; Plattner, G.-K.; Tignor, M.; Allen, S.K.; Boschung, J.; Nauels, A.; Xia, Y.; Bex, V.; Midgley, P.M. (eds.). Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.
  5. ^ Hall, Dorothy K. (1985). Remote Sensing of Ice and Snow. Dordrecht: Springer Netherlands. ISBN 978-94-009-4842-6.
  6. ^ Groisman, Pavel Ya.; Karl, Thomas R.; Knight, Richard W. (14 January 1994). "Observed Impact of Snow Cover on the Heat Balance and the Rise of Continental Spring Temperatures". Science. 263 (5144): 198–200. Bibcode:1994Sci...263..198G. doi:10.1126/science.263.5144.198. PMID 17839175. S2CID 9932394. Retrieved 25 February 2022.
  7. ^ Lynch-Stieglitz, M., 1994: The development and validation of a simple snow model for the GISS GCM. J. Climate, 7, 1842–1855.
  8. ^ Cohen, J., and D. Rind, 1991: The effect of snow cover on the climate. J. Climate, 4, 689–706.
  9. ^ a b Vernekar, A. D., J. Zhou, and J. Shukla, 1995: The effect of Eurasian snow cover on the Indian monsoon. J. Climate, 8, 248–266.
  10. ^ Google Maps: Distance between Wildspitze and Hinterer Brochkogel, cf. image scale at lower edge of screen
  11. ^ Greve, R.; Blatter, H. (2009). Dynamics of Ice Sheets and Glaciers. Springer. doi:10.1007/978-3-642-03415-2. ISBN 978-3-642-03414-5.
  12. ^ Paterson, W. S. B., 1993: World sea level and the present mass balance of the Antarctic ice sheet. In: W.R. Peltier (ed.), Ice in the Climate System, NATO ASI Series, I12, Springer-Verlag, Berlin, 131–140.
  13. ^ Van den Broeke, M. R., 1996: The atmospheric boundary layer over ice sheets and glaciers. Utrecht, Universitiet Utrecht, 178 pp.
  14. ^ Post, Austin; LaChapelle, Edward R (2000). Glacier ice. Seattle: University of Washington Press. ISBN 978-0-295-97910-6.
  15. ^ Staff (June 9, 2020). "Millions at risk as melting Pakistan glaciers raise flood fears". Al Jazeera. Retrieved 2020-06-09.
  16. ^ Craig, Tim (2016-08-12). "Pakistan has more glaciers than almost anywhere on Earth. But they are at risk". The Washington Post. ISSN 0190-8286. Retrieved 2020-09-04. With 7,253 known glaciers, including 543 in the Chitral Valley, there is more glacial ice in Pakistan than anywhere on Earth outside the polar regions, according to various studies.
  17. ^ National Geographic Almanac of Geography, 2005, ISBN 0-7922-3877-X, p. 149.
  18. ^ "170'000 km cube d'eau dans les glaciers du monde". ArcInfo. Aug 6, 2015. Archived from the original on August 17, 2017.
  19. ^ "Ice, Snow, and Glaciers and the Water Cycle". www.usgs.gov. Retrieved 2021-05-25.
  20. ^ Brown, Molly Elizabeth; Ouyang, Hua; Habib, Shahid; Shrestha, Basanta; Shrestha, Mandira; Panday, Prajjwal; Tzortziou, Maria; Policelli, Frederick; Artan, Guleid; Giriraj, Amarnath; Bajracharya, Sagar R.; Racoviteanu,, Adina (November 2010). "HIMALA: Climate Impacts on Glaciers, Snow, and Hydrology in the Himalayan Region". Mountain Research and Development. 30 (4). International Mountain Society: 401–404. doi:10.1659/MRD-JOURNAL-D-10-00071.1. hdl:2060/20110015312. S2CID 129545865.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  21. ^ American Meteorological Society, Glossary of Meteorology Archived 2012-06-23 at the Wayback Machine
  22. ^ "Glossary of Important Terms in Glacial Geology". Archived from the original on 2006-08-29. Retrieved 2006-08-22.
  23. ^ Zwally, H. J., J. C. Comiso, C. L. Parkinson, W. J. Campbell, F. D. Carsey, and P. Gloersen, 1983: Antarctic Sea Ice, 1973–1976: Satellite Passive-Microwave Observations. NASA SP-459, National Aeronautics and Space Administration, Washington, D.C., 206 pp.
  24. ^ a b c Gloersen, P., W. J. Campbell, D. J. Cavalieri, J. C. Comiso, C. L. Parkinson, and H. J. Zwally, 1992: Arctic and Antarctic Sea Ice, 1978–1987: Satellite Passive-Microwave Observations and Analysis. NASA SP-511, National Aeronautics and Space Administration, Washington, D.C., 290 pp.
  25. ^ Parkinson, C. L., J. C. Comiso, H. J. Zwally, D. J. Cavalieri, P. Gloersen, and W. J. Campbell, 1987: Arctic Sea Ice, 1973–1976: Satellite Passive-Microwave Observations, NASA SP-489, National Aeronautics and Space Administration, Washington, D.C., 296 pp.
  26. ^ Parkinson, C. L., 1995: Recent sea-ice advances in Baffin Bay/Davis Strait and retreats in the Bellinshausen Sea. Annals of Glaciology, 21, 348–352.
  27. ^ a b McGee, David; Gribkoff, Elizabeth (4 August 2022). "Permafrost". MIT Climate Portal. Retrieved 27 September 2023.
  28. ^ "What is Permafrost?". International Permafrost Association. Retrieved 27 September 2023.
  29. ^ a b c Denchak, Melissa (26 June 2018). "Permafrost: Everything You Need to Know". Natural Resources Defense Council. Retrieved 27 September 2023.
  30. ^ Cooper, M. G.; Zhou, T.; Bennett, K. E.; Bolton, W. R.; Coon, E. T.; Fleming, S. W.; Rowland, J. C.; Schwenk, J. (4 January 2023). "Detecting Permafrost Active Layer Thickness Change From Nonlinear Baseflow Recession". Water Resources Research. 57 (1): e2022WR033154. Bibcode:2023WRR....5933154C. doi:10.1029/2022WR033154. S2CID 255639677.
  31. ^ Obu, J. (2021). "How Much of the Earth's Surface is Underlain by Permafrost?". Journal of Geophysical Research: Earth Surface. 126 (5): e2021JF006123. Bibcode:2021JGRF..12606123O. doi:10.1029/2021JF006123.
  32. ^ Sayedi, Sayedeh Sara; Abbott, Benjamin W; Thornton, Brett F; Frederick, Jennifer M; Vonk, Jorien E; Overduin, Paul; Schädel, Christina; Schuur, Edward A G; Bourbonnais, Annie; Demidov, Nikita; Gavrilov, Anatoly (22 December 2020). "Subsea permafrost carbon stocks and climate change sensitivity estimated by expert assessment". Environmental Research Letters. 15 (12): B027-08. Bibcode:2020AGUFMB027...08S. doi:10.1088/1748-9326/abcc29. S2CID 234515282.
  33. ^ Schuur, T. (November 22, 2019). "Permafrost and the Global Carbon Cycle". Natural Resources Defense Council – via NOAA.
  34. ^ Koven, Charles D.; Ringeval, Bruno; Friedlingstein, Pierre; Ciais, Philippe; Cadule, Patricia; Khvorostyanov, Dmitry; Krinner, Gerhard; Tarnocai, Charles (6 September 2011). "Permafrost carbon-climate feedbacks accelerate global warming". Proceedings of the National Academy of Sciences. 108 (36): 14769–14774. Bibcode:2011PNAS..10814769K. doi:10.1073/pnas.1103910108. PMC 3169129. PMID 21852573.
  35. ^ Galera, L. A.; Eckhardt, T.; Beer C., Pfeiffer E.-M.; Knoblauch, C. (22 March 2023). "Ratio of in situ CO2 to CH4 production and its environmental controls in polygonal tundra soils of Samoylov Island, Northeastern Siberia". Journal of Geophysical Research: Biogeosciences. 128 (4): e2022JG006956. Bibcode:2023JGRG..12806956G. doi:10.1029/2022JG006956. S2CID 257700504.
  36. ^ a b Fox-Kemper, B., H.T. Hewitt, C. Xiao, G. Aðalgeirsdóttir, S.S. Drijfhout, T.L. Edwards, N.R. Golledge, M. Hemer, R.E. Kopp, G. Krinner, A. Mix, D. Notz, S. Nowicki, I.S. Nurhati, L. Ruiz, J.-B. Sallée, A.B.A. Slangen, and Y. Yu, 2021: Chapter 9: Ocean, Cryosphere and Sea Level Change. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1211–1362.
  37. ^ Schuur, Edward A.G.; Abbott, Benjamin W.; Commane, Roisin; Ernakovich, Jessica; Euskirchen, Eugenie; Hugelius, Gustaf; Grosse, Guido; Jones, Miriam; Koven, Charlie; Leshyk, Victor; Lawrence, David; Loranty, Michael M.; Mauritz, Marguerite; Olefeldt, David; Natali, Susan; Rodenhizer, Heidi; Salmon, Verity; Schädel, Christina; Strauss, Jens; Treat, Claire; Turetsky, Merritt (2022). "Permafrost and Climate Change: Carbon Cycle Feedbacks From the Warming Arctic". Annual Review of Environment and Resources. 47: 343–371. doi:10.1146/annurev-environ-012220-011847. S2CID 252986002.
  38. ^ Robinson, D. A., K. F. Dewey, and R. R. Heim, 1993: Global snow cover monitoring: an update. Bull. Amer. Meteorol. Soc., 74, 1689–1696.
  39. ^ a b Slater, Thomas; Lawrence, Isobel R.; Otosaka, Inès N.; Shepherd, Andrew; Gourmelen, Noel; Jakob, Livia; Tepes, Paul; Gilbert, Lin; Nienow, Peter (25 January 2021). "Review article: Earth's ice imbalance". The Cryosphere. 15 (1): 233–246. Bibcode:2021TCry...15..233S. doi:10.5194/tc-15-233-2021. hdl:20.500.11820/df343a4d-6b66-4eae-ac3f-f5a35bdeef04. Fig. 4.
  40. ^ Rounce, David R.; Hock, Regine; Maussion, Fabien; Hugonnet, Romain; et al. (5 January 2023). "Global glacier change in the 21st century: Every increase in temperature matters". Science. 379 (6627): 78–83. Bibcode:2023Sci...379...78R. doi:10.1126/science.abo1324. PMID 36603094. S2CID 255441012.
  41. ^ Carrer, Marco; Dibona, Raffaella; Prendin, Angela Luisa; Brunetti, Michele (February 2023). "Recent waning snowpack in the Alps is unprecedented in the last six centuries". Nature Climate Change. 13 (2): 155–160. Bibcode:2023NatCC..13..155C. doi:10.1038/s41558-022-01575-3. hdl:11577/3477269. ISSN 1758-6798.
  42. ^ Getting to Know the Cryosphere Archived 15 December 2019 at the Wayback Machine, Earth Labs
  43. ^ Thackeray, Chad W.; Derksen, Chris; Fletcher, Christopher G.; Hall, Alex (2019-12-01). "Snow and Climate: Feedbacks, Drivers, and Indices of Change". Current Climate Change Reports. 5 (4): 322–333. Bibcode:2019CCCR....5..322T. doi:10.1007/s40641-019-00143-w. ISSN 2198-6061. S2CID 201675060.
  44. ^ IPCC, 2019: Technical Summary [H.-O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, E. Poloczanska, K. Mintenbeck, M. Tignor, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.)]. In: IPCC Special Report on the Ocean and Cryosphere in a Changing Climate [H.- O. Pörtner, D.C. Roberts, V. Masson-Delmotte, P. Zhai, M. Tignor, E. Poloczanska, K. Mintenbeck, A. Alegría, M. Nicolai, A. Okem, J. Petzold, B. Rama, N.M. Weyer (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 39–69. doi:10.1017/9781009157964.002
  45. ^ Beckmann, Johanna; Winkelmann, Ricarda (27 July 2023). "Effects of extreme melt events on ice flow and sea level rise of the Greenland Ice Sheet". The Cryosphere. 17 (7): 3083–3099. Bibcode:2023TCry...17.3083B. doi:10.5194/tc-17-3083-2023.
  46. ^ Höning, Dennis; Willeit, Matteo; Calov, Reinhard; Klemann, Volker; Bagge, Meike; Ganopolski, Andrey (27 March 2023). "Multistability and Transient Response of the Greenland Ice Sheet to Anthropogenic CO2 Emissions". Geophysical Research Letters. 50 (6): e2022GL101827. doi:10.1029/2022GL101827. S2CID 257774870.
  47. ^ Bochow, Nils; Poltronieri, Anna; Robinson, Alexander; Montoya, Marisa; Rypdal, Martin; Boers, Niklas (18 October 2023). "Overshooting the critical threshold for the Greenland ice sheet". Nature. 622 (7983): 528–536. Bibcode:2023Natur.622..528B. doi:10.1038/s41586-023-06503-9. PMC 10584691. PMID 37853149.
  48. ^ a b c "How Greenland would look without its ice sheet". BBC News. 14 December 2017. Archived from the original on 7 December 2023. Retrieved 7 December 2023.
  49. ^ Greenland Ice Sheet. 24 October 2023. Archived from the original on 30 October 2017. Retrieved 26 May 2022.
  50. ^ Tan, Ning; Ladant, Jean-Baptiste; Ramstein, Gilles; Dumas, Christophe; Bachem, Paul; Jansen, Eystein (12 November 2018). "Dynamic Greenland ice sheet driven by pCO2 variations across the Pliocene Pleistocene transition". Nature Communications. 9 (1): 4755. doi:10.1038/s41467-018-07206-w. PMC 6232173. PMID 30420596.
  51. ^ Noël, B.; van Kampenhout, L.; Lenaerts, J. T. M.; van de Berg, W. J.; van den Broeke, M. R. (19 January 2021). "A 21st Century Warming Threshold for Sustained Greenland Ice Sheet Mass Loss". Geophysical Research Letters. 48 (5): e2020GL090471. Bibcode:2021GeoRL..4890471N. doi:10.1029/2020GL090471. hdl:2268/301943. S2CID 233632072.
  52. ^ Höning, Dennis; Willeit, Matteo; Calov, Reinhard; Klemann, Volker; Bagge, Meike; Ganopolski, Andrey (27 March 2023). "Multistability and Transient Response of the Greenland Ice Sheet to Anthropogenic CO2 Emissions". Geophysical Research Letters. 50 (6): e2022GL101827. doi:10.1029/2022GL101827. S2CID 257774870.
  53. ^ a b c Bochow, Nils; Poltronieri, Anna; Robinson, Alexander; Montoya, Marisa; Rypdal, Martin; Boers, Niklas (18 October 2023). "Overshooting the critical threshold for the Greenland ice sheet". Nature. 622 (7983): 528–536. Bibcode:2023Natur.622..528B. doi:10.1038/s41586-023-06503-9. PMC 10584691. PMID 37853149.
  54. ^ Christ, Andrew J.; Rittenour, Tammy M.; Bierman, Paul R.; Keisling, Benjamin A.; Knutz, Paul C.; Thomsen, Tonny B.; Keulen, Nynke; Fosdick, Julie C.; Hemming, Sidney R.; Tison, Jean-Louis; Blard, Pierre-Henri; Steffensen, Jørgen P.; Caffee, Marc W.; Corbett, Lee B.; Dahl-Jensen, Dorthe; Dethier, David P.; Hidy, Alan J.; Perdrial, Nicolas; Peteet, Dorothy M.; Steig, Eric J.; Thomas, Elizabeth K. (20 July 2023). "Deglaciation of northwestern Greenland during Marine Isotope Stage 11". Science. 381 (6655): 330–335. Bibcode:2023Sci...381..330C. doi:10.1126/science.ade4248. PMID 37471537. S2CID 259985096.
  55. ^ Aschwanden, Andy; Fahnestock, Mark A.; Truffer, Martin; Brinkerhoff, Douglas J.; Hock, Regine; Khroulev, Constantine; Mottram, Ruth; Khan, S. Abbas (19 June 2019). "Contribution of the Greenland Ice Sheet to sea level over the next millennium". Science Advances. 5 (6): 218–222. Bibcode:2019SciA....5.9396A. doi:10.1126/sciadv.aav9396. PMC 6584365. PMID 31223652.
  56. ^ Armstrong McKay, David; Abrams, Jesse; Winkelmann, Ricarda; Sakschewski, Boris; Loriani, Sina; Fetzer, Ingo; Cornell, Sarah; Rockström, Johan; Staal, Arie; Lenton, Timothy (9 September 2022). "Exceeding 1.5°C global warming could trigger multiple climate tipping points". Science. 377 (6611): eabn7950. doi:10.1126/science.abn7950. hdl:10871/131584. ISSN 0036-8075. PMID 36074831. S2CID 252161375. Archived from the original on 14 November 2022. Retrieved 22 October 2022.
  57. ^ Armstrong McKay, David (9 September 2022). "Exceeding 1.5°C global warming could trigger multiple climate tipping points – paper explainer". climatetippingpoints.info. Archived from the original on 18 July 2023. Retrieved 2 October 2022.
  58. ^ Carlson, Anders E; Walczak, Maureen H; Beard, Brian L; Laffin, Matthew K; Stoner, Joseph S; Hatfield, Robert G (10 December 2018). Absence of the West Antarctic ice sheet during the last interglaciation. American Geophysical Union Fall Meeting.
  59. ^ Lau, Sally C. Y.; Wilson, Nerida G.; Golledge, Nicholas R.; Naish, Tim R.; Watts, Phillip C.; Silva, Catarina N. S.; Cooke, Ira R.; Allcock, A. Louise; Mark, Felix C.; Linse, Katrin (21 December 2023). "Genomic evidence for West Antarctic Ice Sheet collapse during the Last Interglacial". Science. 382 (6677): 1384–1389. Bibcode:2023Sci...382.1384L. doi:10.1126/science.ade0664. PMID 38127761. S2CID 266436146.
  60. ^ A. Naughten, Kaitlin; R. Holland, Paul; De Rydt, Jan (23 October 2023). "Unavoidable future increase in West Antarctic ice-shelf melting over the twenty-first century". Nature Climate Change. 13 (11): 1222–1228. Bibcode:2023NatCC..13.1222N. doi:10.1038/s41558-023-01818-x. S2CID 264476246.
  61. ^ Garbe, Julius; Albrecht, Torsten; Levermann, Anders; Donges, Jonathan F.; Winkelmann, Ricarda (2020). "The hysteresis of the Antarctic Ice Sheet". Nature. 585 (7826): 538–544. Bibcode:2020Natur.585..538G. doi:10.1038/s41586-020-2727-5. PMID 32968257. S2CID 221885420.
  62. ^ a b c Armstrong McKay, David; Abrams, Jesse; Winkelmann, Ricarda; Sakschewski, Boris; Loriani, Sina; Fetzer, Ingo; Cornell, Sarah; Rockström, Johan; Staal, Arie; Lenton, Timothy (9 September 2022). "Exceeding 1.5°C global warming could trigger multiple climate tipping points". Science. 377 (6611): eabn7950. doi:10.1126/science.abn7950. hdl:10871/131584. ISSN 0036-8075. PMID 36074831. S2CID 252161375.
  63. ^ a b c Armstrong McKay, David (9 September 2022). "Exceeding 1.5°C global warming could trigger multiple climate tipping points – paper explainer". climatetippingpoints.info. Retrieved 2 October 2022.
  64. ^ a b c Pan, Linda; Powell, Evelyn M.; Latychev, Konstantin; Mitrovica, Jerry X.; Creveling, Jessica R.; Gomez, Natalya; Hoggard, Mark J.; Clark, Peter U. (30 April 2021). "Rapid postglacial rebound amplifies global sea level rise following West Antarctic Ice Sheet collapse". Science Advances. 7 (18). Bibcode:2021SciA....7.7787P. doi:10.1126/sciadv.abf7787. PMC 8087405. PMID 33931453.
  65. ^ Fretwell, P.; et al. (28 February 2013). "Bedmap2: improved ice bed, surface and thickness datasets for Antarctica" (PDF). The Cryosphere. 7 (1): 390. Bibcode:2013TCry....7..375F. doi:10.5194/tc-7-375-2013. S2CID 13129041. Archived (PDF) from the original on 16 February 2020. Retrieved 6 January 2014.
  66. ^ Crotti, Ilaria; Quiquet, Aurélien; Landais, Amaelle; Stenni, Barbara; Wilson, David J.; Severi, Mirko; Mulvaney, Robert; Wilhelms, Frank; Barbante, Carlo; Frezzotti, Massimo (10 September 2022). "Wilkes subglacial basin ice sheet response to Southern Ocean warming during late Pleistocene interglacials". Nature Communications. 13 (1): 5328. Bibcode:2022NatCo..13.5328C. doi:10.1038/s41467-022-32847-3. PMC 9464198. PMID 36088458.
  67. ^ Fox-Kemper, B., H.T. Hewitt, C. Xiao, G. Aðalgeirsdóttir, S.S. Drijfhout, T.L. Edwards, N.R. Golledge, M. Hemer, R.E. Kopp, G.  Krinner, A. Mix, D. Notz, S. Nowicki, I.S. Nurhati, L. Ruiz, J.-B. Sallée, A.B.A. Slangen, and Y. Yu, 2021: Chapter 9: Ocean, Cryosphere and Sea Level Change. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L.  Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, US, doi:10.1017/9781009157896.011.
  68. ^ Purich, Ariaan; Doddridge, Edward W. (13 September 2023). "Record low Antarctic sea ice coverage indicates a new sea ice state". Communications Earth & Environment. 4 (1): 314. Bibcode:2023ComEE...4..314P. doi:10.1038/s43247-023-00961-9. S2CID 261855193.
  69. ^ "Thermodynamics: Albedo | National Snow and Ice Data Center". nsidc.org. Archived from the original on 11 October 2017. Retrieved 14 October 2020.
  70. ^ "How does sea ice affect global climate?". NOAA. Retrieved 21 April 2023.
  71. ^ "Arctic Report Card 2012". NOAA. Archived from the original on 17 February 2013. Retrieved 8 May 2013.
  72. ^ Huang, Yiyi; Dong, Xiquan; Bailey, David A.; Holland, Marika M.; Xi, Baike; DuVivier, Alice K.; Kay, Jennifer E.; Landrum, Laura L.; Deng, Yi (2019-06-19). "Thicker Clouds and Accelerated Arctic Sea Ice Decline: The Atmosphere-Sea Ice Interactions in Spring". Geophysical Research Letters. 46 (12): 6980–6989. Bibcode:2019GeoRL..46.6980H. doi:10.1029/2019gl082791. hdl:10150/634665. ISSN 0094-8276. S2CID 189968828.
  73. ^ Senftleben, Daniel; Lauer, Axel; Karpechko, Alexey (2020-02-15). "Constraining Uncertainties in CMIP5 Projections of September Arctic Sea Ice Extent with Observations". Journal of Climate. 33 (4): 1487–1503. Bibcode:2020JCli...33.1487S. doi:10.1175/jcli-d-19-0075.1. ISSN 0894-8755. S2CID 210273007.
  74. ^ Yadav, Juhi; Kumar, Avinash; Mohan, Rahul (2020-05-21). "Dramatic decline of Arctic sea ice linked to global warming". Natural Hazards. 103 (2): 2617–2621. Bibcode:2020NatHa.103.2617Y. doi:10.1007/s11069-020-04064-y. ISSN 0921-030X. S2CID 218762126.
  75. ^ IPCC, 2018: Summary for Policymakers. In: Global Warming of 1.5 °C. An IPCC Special Report on the impacts of global warming of 1.5 °C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA, pp. 3-24. doi:10.1017/9781009157940.001.
  76. ^ Fox-Kemper, B., H.T. Hewitt, C. Xiao, G. Aðalgeirsdóttir, S.S. Drijfhout, T.L. Edwards, N.R. Golledge, M. Hemer, R.E. Kopp, G. Krinner, A. Mix, D. Notz, S. Nowicki, I.S. Nurhati, L. Ruiz, J.-B. Sallée, A.B.A. Slangen, and Y. Yu, 2021: Chapter 9: Ocean, Cryosphere and Sea Level Change. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, US doi:10.1017/9781009157896.011
  77. ^ "Understanding climate: Antarctic sea ice extent". NOAA Climate.gov. 14 March 2023. Retrieved 2023-03-26.
  78. ^ a b Fox-Kemper, B., H.T. Hewitt, C. Xiao, G. Aðalgeirsdóttir, S.S. Drijfhout, T.L. Edwards, N.R. Golledge, M. Hemer, R.E. Kopp, G.  Krinner, A. Mix, D. Notz, S. Nowicki, I.S. Nurhati, L. Ruiz, J.-B. Sallée, A.B.A. Slangen, and Y. Yu, 2021: Chapter 9: Ocean, Cryosphere and Sea Level Change. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L.  Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1211–1362, doi:10.1017/9781009157896.011.
  79. ^ Li, Chuanhua; Wei, Yufei; Liu, Yunfan; Li, Liangliang; Peng, Lixiao; Chen, Jiahao; Liu, Lihui; Dou, Tianbao; Wu, Xiaodong (14 June 2022). "Active Layer Thickness in the Northern Hemisphere: Changes From 2000 to 2018 and Future Simulations". JGR Atmospheres. 127 (12): e2022JD036785. Bibcode:2022JGRD..12736785L. doi:10.1029/2022JD036785. S2CID 249696017.
  80. ^ Overduin, P. P.; Schneider von Deimling, T.; Miesner, F.; Grigoriev, M. N.; Ruppel, C.; Vasiliev, A.; Lantuit, H.; Juhls, B.; Westermann, S. (17 April 2019). "Submarine Permafrost Map in the Arctic Modeled Using 1-D Transient Heat Flux (SuPerMAP)" (PDF). Journal of Geophysical Research: Oceans. 124 (6): 3490–3507. Bibcode:2019JGRC..124.3490O. doi:10.1029/2018JC014675. hdl:1912/24566. S2CID 146331663.
  81. ^ "Frozen Ground, the News Bulletin of the IPA". International Permafrost Association. 2014-02-10. Retrieved 2016-04-28.
  82. ^ a b Fox-Kemper, B.; Hewitt, H.T.; Xiao, C.; Aðalgeirsdóttir, G.; Drijfhout, S.S.; Edwards, T.L.; Golledge, N.R.; Hemer, M.; Kopp, R.E.; Krinner, G.; Mix, A. (2021). Masson-Delmotte, V.; Zhai, P.; Pirani, A.; Connors, S.L.; Péan, C.; Berger, S.; Caud, N.; Chen, Y.; Goldfarb, L. (eds.). "Ocean, Cryosphere and Sea Level Change" (PDF). Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. 2021. Cambridge University Press, Cambridge, UK and New York, NY, USA: 1283–1285. doi:10.1017/9781009157896.011. ISBN 9781009157896.
  83. ^ Pederson, Gregory T.; Gray, Stephen T.; Woodhouse, Connie A.; Betancourt, Julio L.; Fagre, Daniel B.; Littell, Jeremy S.; Watson, Emma; Luckman, Brian H.; Graumlich, Lisa J. (2011-07-15). "The Unusual Nature of Recent Snowpack Declines in the North American Cordillera". Science. 333 (6040): 332–335. Bibcode:2011Sci...333..332P. doi:10.1126/science.1201570. ISSN 0036-8075. PMID 21659569. S2CID 29486298.
  84. ^ Belmecheri, Soumaya; Babst, Flurin; Wahl, Eugene R.; Stahle, David W.; Trouet, Valerie (2016). "Multi-century evaluation of Sierra Nevada snowpack". Nature Climate Change. 6 (1): 2–3. Bibcode:2016NatCC...6....2B. doi:10.1038/nclimate2809. ISSN 1758-6798.
  85. ^ Brown, Ross D.; Goodison, Barry E.; Brown, Ross D.; Goodison, Barry E. (1996-06-01). "Interannual Variability in Reconstructed Canadian Snow Cover, 1915–1992". Journal of Climate. 9 (6): 1299–1318. Bibcode:1996JCli....9.1299B. doi:10.1175/1520-0442(1996)009<1299:ivircs>2.0.co;2.
  86. ^ Hughes, M. G.; Frei, A.; Robinson, D.A. (1996). "Historical analysis of North American snow cover extent: merging satellite and station-derived snow cover observations". Proceedings of the Annual Meeting - Eastern Snow Conference. Williamsburg, Virginia: Eastern Snow Conference. pp. 21–31. ISBN 9780920081181.
  87. ^ Groisman, P. Ya, and D. R. Easterling, 1994: Variability and trends of total precipitation and snowfall over the United States and Canada. J. Climate, 7, 184–205.
  88. ^ Prinsenberg, S. J. 1988: Ice-cover and ice-ridge contributions to the freshwater contents of Hudson Bay and Foxe Basin. Arctic, 41, 6–11.

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