Ice

Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaque bluish-white color.

The most common phase transition to ice Ih occurs when liquid water is cooled below 0 °C (273.15 K, 32 °F) at standard atmospheric pressure.

[6] An unusual property of water is that its solid form—ice frozen at atmospheric pressure—is approximately 8.3% less dense than its liquid form; this is equivalent to a volumetric expansion of 9%.

Instead, a sheltered environment for animal and plant life is formed beneath the floating ice, which protects the underside from short-term weather extremes such as wind chill.

[10] When sea water freezes, the ice is riddled with brine-filled channels which sustain sympagic organisms such as bacteria, algae, copepods and annelids.

[12][8] As with water, ice absorbs light at the red end of the spectrum preferentially as the result of an overtone of an oxygen–hydrogen (O–H) bond stretch.

Since absorption is cumulative, the color effect intensifies with increasing thickness or if internal reflections cause the light to take a longer path through the ice.

[21] With care, at least fifteen of these phases (one of the known exceptions being ice X) can be recovered at ambient pressure and low temperature in metastable form.

However, the significance of this hypothesis is disputed by experiments showing a high coefficient of friction for ice using atomic force microscopy.

[42][43] The World Meteorological Organization defines several kinds of ice depending on origin, size, shape, influence and so on.

As they become somewhat larger and more consistent in shape and cover, the water surface begins to look "oily" from above, so this stage is called grease ice.

They form within eddy currents, and their position results in asymmetric melting, which makes them continuously rotate at a low speed.

This kind of ice may contain large air pockets under a thin surface layer, which makes it particularly hazardous to walk across it.

In the United States, a quarter of winter weather events produce glaze ice, and utilities need to be prepared to minimize damages.

[76] Hail forms in storm clouds when supercooled water droplets freeze on contact with condensation nuclei, such as dust or dirt.

Ice pellets typically form alongside freezing rain, when a wet warm front ends up between colder and drier atmospheric layers.

[93] More generally, water vapor depositing onto surfaces due to high relative humidity and then freezing results in various forms of atmospheric icing, or frost.

[95] In Antarctica, the temperatures can be so low that electrostatic attraction is increased to the point hoarfrost on snow sticks together when blown by wind into tumbleweed-like balls known as yukimarimo.

[101][102] In recent decades, irrigation sprinklers have been calibrated to spray just enough water to preemptively create a layer of ice that would form slowly and so avoid a sudden temperature shock to the plant, and not be so thick as to cause damage with its weight.

Yakhchals often included a qanat and a system of windcatchers that could lower internal temperatures to frigid levels, even during the heat of the summer.

[106][107] There were thriving industries in 16th–17th century England whereby low-lying areas along the Thames Estuary were flooded during the winter, and ice harvested in carts and stored inter-seasonally in insulated wooden houses as a provision to an icehouse often located in large country houses, and widely used to keep fish fresh when caught in distant waters.

[115] Most commercial icemakers produce three basic types of fragmentary ice: flake, tubular and plate, using a variety of techniques.

[119] Whenever there is freezing rain or snow which occurs at a temperature near the melting point, it is common for ice to build up on the windows of vehicles.

[120] A thin layer of ice crystals can also form on the inside surface of car windows during sufficiently cold weather.

It operated in the winters of 1941–1942 and 1942–1943, when it was the only land route available to the Soviet Union to relieve the Siege of Leningrad by the German Army Group North.

Firstly, spray and freezing rain can produce an ice build-up on the superstructure of a vessel sufficient to make it unstable, potentially to the point of capsizing.

[128] Secondly, icebergs – large masses of ice floating in water (typically created when glaciers reach the sea) – can be dangerous if struck by a ship when underway.

In 1919, during the first non-stop flight across the Atlantic, the British aviators Captain John Alcock and Lieutenant Arthur Whitten Brown encountered such icing conditions – Brown left the cockpit and climbed onto the wing several times to remove ice which was covering the engine air intakes of the Vickers Vimy aircraft they were flying.

[140] Greenhouse gas emissions from human activities unbalance the Earth's energy budget and so cause an accumulation of heat.

[158][159] The West Antarctic ice sheet is highly vulnerable and will likely disappear even if the warming does not progress further,[164][165][166][167] although it could take around 2,000 years before its loss is complete.

The three-dimensional crystal structure of H 2 O ice I h (c) is composed of bases of H 2 O ice molecules (b) located on lattice points within the two-dimensional hexagonal space lattice (a). [ 4 ] [ 5 ]
Frozen waterfall in southeast New York
Log-lin pressure-temperature phase diagram of water. The Roman numerals correspond to some ice phases listed below.
An alternative formulation of the phase diagram for certain ices and other phases of water [ 15 ]
Takahiko Kozuka figure skating - an act which is only possible due to ice's low frictional properties
Frozen landscape in the Northwest Territories of Canada . A large ice circle can be clearly seen floating on water. [ 40 ] [ 41 ]
NASA image of the Antarctic ice sheet
A small frozen rivulet
Candle ice in Lake Otelnuk, Quebec, Canada
A large hailstone, about 6 cm (2.4 in) in diameter
Soft hail, or graupel, in Nevada
An accumulation of ice pellets
Different stages of ice melt in a pond
The melting of floating ice
A schematic showing how the ancient yakhchals used ice to provide radiative cooling
Harvesting ice on Lake St. Clair in Michigan , c. 1905
Layout of a late 19th-century ice factory
Ice formation on exterior of vehicle windshield
1943 US propaganda film explaining how the ice of Lake Ladoga became the Road of Life during WWII
Channel through ice for ship traffic on Lake Huron with ice breakers in background
Rime ice on the leading edge of an aircraft wing. When the build-up is too large, the black deicing boot inflates to shake it off [ 131 ] [ 132 ]
Skating fun by 17th century Dutch painter Hendrick Avercamp
Ice pier during 1983 cargo operations. McMurdo Station , Antarctica.
An ice-made dining room of the Kemi 's SnowCastle ice hotel in Finland
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. [ 151 ] The rate of ice loss has risen by 57% since the 1990s−from 0.8 to 1.2 trillion tonnes per year. [ 151 ]
On average, climate change has lowered the thickness of land ice with every year, and reduced the extent of sea ice cover. [ 151 ]
Potential regional warming caused by the loss of all land ice outside of East Antarctica, and by the disappearance of Arctic sea ice every year starting from June. [ 156 ] While plausible, consistent sea ice loss would likely require relatively high warming, [ 157 ] and the loss of all ice in Greenland would require multiple millennia. [ 158 ] [ 159 ]
Possible equilibrium states of the Greenland 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). [ 162 ]