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An introduction to the issue of temperature in antarctica

Climate The unique weather and climate of Antarctica provide the basis for its familiar appellations—Home of the Blizzard and White Desert.

Temperatures vary greatly from place to place, but direct measurements in most places are generally available only for summertime. Only at fixed stations operated since the IGY have year-round measurements been made. The glaciers and ice sheets of Antarctica may document such change, especially in West Antarctica.

Average winter temperatures on the Antarctic Peninsula have increased by 10. Map showing the extent of collapse of the Larsen Ice Shelf. Both events were caused by water from surface melting that ran down into crevasses, refroze, and wedged each shelf into pieces. Wind chill —the cooling power of wind on exposed surfaces—is the major debilitating weather factor of Antarctic expeditions.

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Fierce winds characterize most coastal regions, particularly of East Antarctica, where cold, dense air flows down the steep slopes off interior highlands. Known as katabatic windsthey are a surface flow that may be smooth if of low velocity but that may also become greatly turbulent, sweeping high any loose snowif a critical velocity is surpassed.

During one winter at Mirny Station, gusts reached more than 110 miles per hour on seven occasions. Gusts estimated at between 140 and 155 miles per hour on December 9, 1960, destroyed a Beaver aircraft at Mawson Station on the Mac.

  • The warming of the Antarctic Peninsula is causing changes to the physical and living environment of Antarctica;
  • Only at fixed stations operated since the IGY have year-round measurements been made.

Winds on the polar plateau are usually light, with monthly mean velocities at the South Pole ranging from about 9 miles per hour 4 metres per second in December summer to 17 miles per hour 8 metres per second in June and July winter. The Antarctic atmospherebecause of its low temperature, contains only about one-tenth of the water-vapour concentration found in temperate latitudes. Most of this water precipitates as snow along the continental margin.

Rain is almost unknown.

  1. Antarctica, and particularly the South Pole, attracts much interest in astronomical and astrophysical studies as well as research on the interactions between the Sun and the upper atmosphere of Earth.
  2. It is hypothesised that water from large surface melt ponds that formed on the ice shelf as a result of this warming forced open cracks and crevasses to completely fracture the shelf.
  3. The chemical reactions take place with the arrival of sunlight in spring and are facilitated by the presence of halogens chlorine and fluorine , which are mostly products of human activity. Deep ice cores have yielded evidence of major interrelated climate and cryosphere fluctuations in glacial-interglacial cycles.
  4. The Australian Antarctic glaciology program contributes to this program with cryosphere studies taking in Antarctic sea ice, the continental ice sheet including ice core climate records, subantarctic glaciers and abrupt change.

Lacking a heavy and protective water-vapour-rich atmospheric layer, which in other areas absorbs and reradiates to Earth long-wave radiationthe Antarctic surface readily loses heat energy into space.

Only a few coastal fringes lie north of the Antarctic Circle. The amount of incoming solar radiationand thus heat, depends additionally on the incident angle of the rays and therefore decreases inversely with latitude to reach a minimum at the geographic poles. These and other factors are essentially the same for both polar regions.

Impacts of climate change

The reason for their great climatic difference primarily lies in their reverse distributions of land and sea: The Arctic Oceana climate-ameliorating heat source, has no counterpart at the South Polethe great elevation and perpetually reflective snow cover of which instead intensify its polar climate. Moreover, during Antarctic winters, freezing of the surrounding sea effectively more than doubles the size of the continent and removes the oceanic heat source to nearly 1,800 miles from the central polar plateau.

Outgoing terrestrial radiation greatly exceeds absorbed incoming solar radiation. This loss results in strong surface cooling, giving rise to the characteristic Antarctic temperature inversions in which temperature increases from the surface upward to about 1,000 feet above the surface.

About 90 percent of the loss is replaced by atmospheric heat from lower latitudes, and the remainder by latent heat of water-vapour condensation. Great cyclonic storms circle Antarctica in endless west-to-east procession, exchanging atmospheric heat to the continent from sources in the southern AtlanticPacificand Indian oceans.

Australian Antarctic Division: Leading Australia’s Antarctic Program

Few storms bring snowfalls to interior regions. With few reporting stations, weather prediction has been exceedingly difficult but is now greatly aided by satellite imagery. Ozone is destroyed as the result of chemical reactions on the surfaces of particles in polar stratospheric clouds PSCs.

The chemical reactions take place with the arrival of sunlight in spring and are facilitated by the presence of halogens chlorine and fluorinewhich are mostly products of human activity. Antarctica, and particularly the South Pole, attracts much interest in astronomical and astrophysical studies as well as research on the interactions between the Sun and the upper atmosphere of Earth.

  • Many glaciers have retreated and ice shelves that formerly fringed the Peninsula have been observed to retreat in recent years and some have collapsed completely;
  • Accurate information on local, regional and global climate change and potential changes in ice sheet surface elevation are available from ice cores.

The South Pole is a unique astronomical location a station from which the Sun can be viewed continuously in summer sitting at a high geomagnetic latitude with unequaled atmospheric clarity. It possesses a thick section of pure material ice that can be used as a cosmic particle detector. CARA supports a submillimetre-wave telescopeseveral other telescopes, and a program to measure the properties of relict radiation left over from the big bang —useful in testing cosmological models.

This involves an array of hundreds of optical devices set at depths of up to 1. It is essentially a telescope built within the ice sheet to detect high-energy neutrinos that pass through the Earth from distant sources.

  1. Wind chill —the cooling power of wind on exposed surfaces—is the major debilitating weather factor of Antarctic expeditions. Ice and snow the 'cryosphere' are important components of climate, with snow in particular limiting absorption of solar energy at the surface through its high reflectivity 'albedo'.
  2. The Arctic Ocean , a climate-ameliorating heat source, has no counterpart at the South Pole , the great elevation and perpetually reflective snow cover of which instead intensify its polar climate.
  3. When the ice forms it ejects salt to the ocean, destabilising the water column and deepening the surface mixed layer.
  4. It has now been established that the Antarctic Circumpolar Current is warming more rapidly than the global ocean as a whole. Retreat of non-polar glaciers has contributed to sea level rise over the past century while also providing clear evidence of a changing climate.