Glaciers And Climate Change Environmental Sciences Essay

The commodity is mainly allocution about the alternation amid glaciers and distance change. Booty the Tianshan No.1 Berg as an example. Berg produces in distance and by the appulse of distance change. The glaciers change is the aftereffect of distance fluctuations. And berg changes in about-face acts on the accustomed ambiance that accord to distance change. Tianshan No.1 Berg has afflicted decidedly in the accomplished bristles decades, includes berg apparent firn characteristics, ice accession zones, ice temperature, thickness, breadth and abuttals position, etc. These berg changes accompanying to temperature rise, and acknowledge to contempo distance variation. In addition, changes in the all-around distance and ambiance acquired by berg change, such as the access of berg runoff, sea-level rise, and the abridgement of apparent albedo acquired by breadth abbreviating etc. The alternation amid berg and distance change not alone has important impacts on all-around distance variation, but additionally has abundant acceptation for the abstraction of distance and environment.

1. Introduction

Glacier is a ample assiduous anatomy of ice that forms breadth the accession of snow exceeds its ablation (melting and sublimation) over abounding years, generally centuries. Its movement acquired by the activity of gravity. Berg ice is the better backlog of freshwater, acknowledging one third of the world’s population. 11% of the world’s acreage breadth is covered by glaciers. The berg mainly broadcast in the Antarctic, the Arctic and high-altitude regions of the boilerplate and low latitudes. It is a artefact of the distance and a acceptable indicator of climate, additionally it acts on climate. The glaciers change, abnormally changes in abundance glaciers, is a barometer of all-around distance change. Precipitation, temperature is the basic distance factors that affecting glaciers. The precipitation decides berg accumulation, and temperatures adjudge ablation. Therefore, the bulk of precipitation, its administration during the year, and interannual airheadedness aftereffect berg recharge and activities. While the temperature impacts ice accession and arctic cook water. The precipitation and temperature codetermine the attributes of the glacier, development and evolution.

1.1 Berg accession balance

Glacier accession antithesis is the key agency that links berg fluctuations and distance change. Distance change leads to agnate changes in the actual antithesis accompaniment of glacier. While this affectionate of change in the accession antithesis of berg can beforehand to change in berg movement characteristics and berg thermal regime, and appropriately beforehand to changes in the berg abuttals position, admeasurement and ice reserves.

Glacier accession antithesis formular has two elements: berg accession and ablation. Berg ice accession occurs through accession of snow and alternative arctic precipitations, accommodate aperture ice, avalanching from blind glaciers on cliffs and mountainsides above, and re-freezing of berg cook baptize as superimposed ice. The ablation refers to the melting of snow or ice that runs off the glacier, evaporation, sublimation, calving, or cutting abatement of snow by wind. Air temperature is about the ascendant ascendancy of ablation with precipitation appliance accessory control. With alternating years in which accession exceeds ablation, a berg will acquaintance absolute accession balance, its abuttals will beforehand and carnality versa.

1.2 Research Significance

Current berg recession beneath the all-around abating has angry all-embracing attention. The acuteness of aerial glaciers to temperature change is begin to be abundantly amplified. The cardinal of beat glaciers has bigger significantly. For a cardinal of glaciers, abbreviating amount appears to accept accelerated aback the 1990s. Access melting dispatch of glaciers can beforehand to sea akin dispatch and submerging of some littoral areas. Moreover, it induces snow and ice accompanying disasters, for example, berg flood and avalanche, which annoyance the alive ambiance of animal beings and agrarian animals, as able-bodied as change the habits and characteristics of abounding species. On the alternative hand, the dematerialization of arctic regions on the Earth will in about-face change the all-around distance administration significantly. Ice covers, abnormally those in the Arctic Regions, can reflect a abundant accord of solar activity aback to the alien space, which helps to accrue the Earth cool. However, with the ice awning melting, the underlain acreage and the baptize will betrayal to the air, and appropriately absolutely blot abundant added solar radiation and account added ice melting. The accelerated berg recession in China is additionally actual obvious, abnormally in Northwest China, breadth berg cook baptize runoff increases, breadth of berg decreases, abuttals retreats, snow band elevates and abounding baby glaciers are disappearing. Berg is accepted as the solid backlog and the cradle of haven in the barren regions in Northwest China. It is the aloft baptize antecedent for animal alive and development.

Study area

Tianshan No.1 Glacier(43°6′N¼Œ 86°49′E) is amid at a acme of 3,454 m aloft sea level, and about 118 km from Urumqi, the basic of Xinjiang Uygur Free Arena in China. It is the headwaters of Urumqi River, about 100km from Asia geographic center. In addition, it is advised one of the best important dry acreage berg models in Asia, and one of the best acclaimed ten glaciers in the world.

It has the longest almanac of accession antithesis in the Asian aerial mountains. The arctic almanac shows that the berg has diminished decidedly in aftermost 30 years. The Tianshan No.1 berg is shrinking at the dispatch of 3.5 m and 5.9 m every year on its east and west abandon respectively. In the accomplished 45 years, its advantage has alone from 1.94 sq km to 1.68 sq km, a 13.8% loss. The acreage actuality is appropriate of alluvial deposits by glaciers, so those administering geological surveys can analyze the development beforehand of the Urumqi River in the accomplished millions of years.

Glacier-climate interactions

The glaciers change is the assured aftereffect of distance fluctuations. Atmospheric precipitation and calefaction cachet changes, abstruse appulse on the beforehand and abatement of the beforehand and retreat of the arctic ice caps and abundance glaciers. By celebratory the berg changes, compassionate the berg activating of all-around or regional, and forecasting all-around distance change. Glaciers in China are mainly baby and medium-sized abundance glaciers in low latitude. They accept a acceptable acknowledgment for distance fluctuations of abbreviate cycle.

Since the Little Ice Age, the accepted trend of glaciers about the apple is retreat mainly. The Fourth Assessment Report of IPCC (Intergovernmental Panel on Distance Change) acicular out that impacts of distance abating on abounding phenomena are remarkable, such as abbreviating of the Arctic ice cap, dispatch of sea akin rise, recession of berg abuttals all over the world, thawing of permafrost, beforehand breaking up of ice in the rivers and lakes, assiduity of crop growing division in the boilerplate and aerial latitudes, and changes in the administration and behavior of animals and plants.

Take Tianshan No.1 Berg as an example, berg has afflicted decidedly in the accomplished bristles decades, includes berg apparent firn characteristics, ice accession zones, ice temperature, thickness, breadth and abuttals position, etc.

The basic drive armament to the berg change are the calefaction and baptize distance of the berg covered region. Berg melting is deeply accompanying to the temperature variation. According to the annal of meteorological stations in the headwaters region, the air temperature has been ascent aback 1985, and the addiction of dispatch has accelerated aback 1995. From 1997 up to present, the boilerplate temperature has added by 1℃, as the better dispatch admeasurement in contempo 50 years. The ascertainment of Daxigou Meteorological Station shows that the boilerplate anniversary temperature added by 0.8℃(0.017℃/a) during 1958~2004 with accessible temperature rises abnormally in autumn and winter.

The characteristics of snow-firn stratigraphy and ice accession breadth of the berg are acute to the distance change. The distance abating abundantly promotes the berg melting, which appropriately alters the backdrop of snow backpack stratigraphy and ice accession zones. According to the analyses of 60 vertical profiles of snow pits acquired from the accession breadth of Tianshan No. 1 Berg during the aeon of 1961~2005, the architecture of snowfirn stratigraphy had a arresting change. The admeasurement of base firn in the snow pits added from 40% to 65%, and accomplished firn decreased from 25% to 7%. This indicates that snow backpack is acutely afflicted by cook water, which accelerates the action of transformation from accomplished firn to base firn. Compared with the snow-firn stratigraphic capacity and its anatomy in the 1960s and 1980s, accepted specimens appearance arresting changes, such as abridgement of snow-pack depth, description of structure, blurred boundaries of snow layers, and affiliation of dust layers aural snow pack.

The accession antithesis change is an undelayed acknowledgment of the berg to distance change, and it is a acute indicator for distance change. For the accession antithesis of Tianshan No. 1 Glacier, both anniversary amount and accumulative amount accept apparent abrogating increases aback 1958, advertence astringent accession losses. In time of 1958-2004, there were 31 abrogating accession antithesis years adjoin 15 absolute years. From 1997 to today, the abrogating accession antithesis has lasted for 10 years, which never happened anytime before. The boilerplate anniversary accession antithesis during 1958-2004 was -233.6 mm baptize agnate (weq) and the accumulative accession antithesis added up to -10746.5 mm weq, which agency that the boilerplate array of the berg about bargain 12 m and the aggregate accident was about 20.62-106m3 weq.

Unlike the glaciers in Europe and mid-America, which accrue in winter and lose accession in summer, Tianshan No. 1 Berg has both accession and ablation in summer, and there is little blast in winter. Antecedent researches on Tianshan No.1 Berg accept apparent that the accession antithesis was affiliated with the precipitation, and abnormally activated with air temperature in summer (May to August). However, with the access in both accepted temperature and precipitation, accession antithesis has adapted responses to them.

Retreat of berg and its impact

Under the distance warming, the law of abuttals recession and ice array abridgement are followed by berg shrinkage. The changes of berg breadth and abuttals position aftereffect from concise and abiding distance changes. Tianshan No. 1 Berg has an all-embracing abbreviating aback the year 1959 back the ascertainment initiated. The east and west branches of Tianshan No. 1 Berg afar into two absolute glaciers in 1993 due to ablation, during this aeon (1959~1993) the absolute abuttals retreat was empiric as 139.72 m at an boilerplate retreat amount of 4.5 m per year. From 1993 to 2004, the east annex of Tianshan No. 1 Berg aloof at an boilerplate amount of 3.5 m per year (a absolute of 38.7 m), and the west annex aloof at a amount of 5.8 m per year (a absolute of 64.1 m). The recession amount (the arrangement of receded breadth to the aboriginal berg length) of Tianshan No. 1 Berg was 7.8% in the aeon of 1962~2004 for the east annex and 10.5% for the west branch, respectively. The west annex abuttals aloof 6.92 m in 1999 and 6.95 m in 2000, respectively, which are the accomplished annal in the ascertainment records. Aback the ice breeze velocities in agnate years were empiric abiding at terminus, it is absurd that the cogent retreats were acquired by the abridgement of ice alteration from aerial genitalia of the glacier, and thus, it is acutely due to the acute ice melting. With abuttals receding, its distance accompanying animated from 3736 m a.s.l in 1962 to 3746m a.s.l in 1980, and the east annex abuttals distance in 2005 was 3777 m a.s.l, 31 m college than that in 1980. Arctic ablation will not alone beforehand to floods, landslides and alternative accustomed disasters, but additionally beforehand berg runoff additionally to be reduced, and accomplish the afterwards freshwater assets gradually scarcity.

Research

Cumulative temperature is a aloft agency affecting berg ablation. Accumulative temperature, namely, the sum of circadian beggarly air temperature aloft the melting point during ablation division is carefully accompanying to the breadth of berg ablation zone. According to the antecedent studies, the anniversary accumulative temperature in the headwaters arena of Urumqi River rose by 133℃•d during 1960~2004. Its addiction is ancillary with that of boilerplate anniversary temperature, i.e. aback the backward 1980s the accumulative temperature has risen remarkably, and meanwhile the distance abating showed a accelerated addiction (see Fig.1).

Fig. 1 Accession antithesis of Tianshan Berg No. 1, accumulated temperature (T¼ž0℃) and their trends during 1958~2003

During the aeon of 1962~2006, the breadth of Tianshan No. 1 Berg bargain by 0.27 km2. From 1992 to 2006, the berg breadth decreased by 0.16 km2, which is 0.04 km2 added than that from 1962 to 1992. Based on the ascertainment over the accomplished 43 years, glaciologists begin that the abatement of berg breadth has accelerated aback 1986. Figure 2 shows the recession action of the berg terminus, and Fig. 3 displays the morphological shapes of Tianshan No. 1 Berg in adapted years.

Fig. 2 Morphological change of Tianshan No. 1 Berg over time.(Dashed curve represent the arctic boundaries of 1962, 1973,1980, 1984, 1986, 1994 and 2001; solid curve represent the arctic abuttals of 2006)

Fig. 3 Morphological changes of Tianshan No. 1 Berg in the years of 1962, 1988, 1993,1996, 2001, and 2005

Glacial temperature, abnormally the temperature of the ice beneath alive layers, determines abounding concrete characteristics of the glacier. The change of ice temperature indicates the change in the glacier’s algid reserve, which can account the change of the acuteness of the berg in acknowledgment to distance warming. Comparing with three vertical profiles of ice temperature at the distance of 3840 m in the years of 1986, 2001 and 2006 (Fig. 4), The glaciologist begin that it is about 10m in abyss that the lower abuttals of the alive band of the glacier, beneath which the ice temperature is little afflicted by the melancholia aberration of air temperature. If blank the change of the ice temperature in alive layer, the ice temperature from 10 to 22 m in abyss had a arresting dispatch during 1986~2001. The dispatch ambit decreased with the better amount of 0.9℃ (10%) at 10 m abyss beneath ice apparent and a negligible change at 22 m depth. Similarly, compared with the ice temperature in 2001, the ice temperature in 2006 had an accessible rise, with an access of 0.4℃ at 10 m depth. Usually, the ice temperature at the lower abuttals of alive band is identical with the anniversary boilerplate air temperature. Therefore, the dispatch of ice temperature is assuredly the aftereffect of progressively distance warming.

Fig. 4 Comparison of ice temperature profiles acquired in 1986, 2001 and 2006 at a armpit about 3840 m a.s.l on No. 1 Berg in Tianshan Mountain

Fig. 5 Anniversary accession antithesis of Tianshan No. 1 Berg adjoin summer temperature (May-August), anniversary temperature and anniversary precipitation at Daxigou Meteorological Station

Figure 5 shows the variations of accession balance, summer temperature, anniversary temperature and precipitation during1959-2004, from which researcher begin that during 1960-1986 the accession antithesis had a anemic abrogating alternation with temperature, while a bright absolute alternation with precipitation, advertence that the accession antithesis is controlled by both temperature and precipitation, with precipitation as the basic factor. During this period, the anniversary boilerplate temperature and precipitation were -5.4℃and 425.8 mm, respectively. However, the alternation has adapted aback 1986. The accession antithesis showed a abrogating alternation with temperature and no alternation with precipitation, advertence that the accession antithesis was mainly controlled by temperature. During this period, boilerplate anniversary temperature and precipitation were -4.9℃and 491.6 mm, respectively. The after-effects appearance that temperature and precipitation are usually ascendancy accession balance, but temperature is mainly ascendancy accession antithesis back temperature rises to a assertive level, admitting with aerial precipitation.

Existing action for distance change adaptation

As aboriginal as in 2006, the Urumqi borough government had fabricated ​​provisions: from abuse to assure important baptize antecedent in Urumqi, prohibit visitors in Tianshan Glacier. But the absence of angry and secure, some tourists into the berg arena through assorted ways, afflicted the ambiance of the glacier. The agent of free regions, Chunyu Cui, proposed to authorize an areas about National Tianshan Berg attributes affluence of Xinjiang in 2012. But the action had not yet been introduced.

Conclusions and recommendations

Conclusions

Taking Tianshan No. 1 Berg as an example, this commodity allocution about the acknowledgment of berg to accepted distance abating based on the ascertainment dataset of 50 years. The cessation was fatigued as follows:

Since the 1960s, snow firn stratigraphic apparatus and anatomy accept apparent arresting changes, including abbreviation snow backpack depth, simplifying structure, and abashing boundaries of snow layers with adapted characteristics. The breadth of berg ablation breadth keeps expanding, the positions of ice accession zones move upwards, and the top of east annex has already apparent the appropriate of ablation zone.

During 1962~2006, the breadth of Tianshan No. 1 Berg bargain by 0.27 km2 (14%). The shrinking addiction has accelerated in contempo years. At the distance of 3840 m a.s.l, a cogent dispatch in the ice temperature was empiric during 1986-2001, with the accomplished dispatch amount of 0.9℃ at abyss of10 m. From 2001 to 2006, the ice temperature rose by 0.4℃at abyss of 10 m.

Average anniversary accession antithesis during 1958-2004 was -233.6 mm weq, with the accumulative accession antithesis of-10746.5 mm weq, which indicates that the array of Tianshan No. 1 Berg bargain about 12 m and accident of aggregate came to about 20.62-106 m3. Accession antithesis is controlled by both temperature and precipitation afore 1986, with precipitation as the basic factor. But afterwards 1986, accession antithesis is controlled mainly by temperature, admitting with aerial precipitation.

Recommendations

In adjustment to assure the glaciers, abounding experts achievement to booty measures as anon as accessible to assure the accustomed ambiance of the glaciers in Xinjiang in accordance with the law, apathetic bottomward counterfeit destruction. On the alternative hand, animate and abutment to use the bogus acclimate absolutely developed air baptize resources, to backpack out the bogus baptize project, in adjustment to access the glaciers snow.

There are some suggestions:

Through activity conservation, development of accustomed gas, hydropower, atramentous bed methane utilization, bio-energy, wind energy, solar energy, geothermal energy. Strengthen the planning and accomplishing of ecological architecture and ecology protection.

Strengthening distance change advice and accurate popularization to accession acquaintance of distance change in the accomplished society.

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