Distribution Features Of Temperatures And Heat Transfer On The Glacier Of Austre Lovénbreen, Svalbard, Arctic

The glacier is the body of the Cryosphere on earth, and function as indicationand records of the climate and environment changes. Ice temperature is the basicphysical characteristics of glacier and it is the key to know the existence anddevelopment of glacier. The glacier temperature is related to its movement, iceformation process and englacial water, glacier surging and glacier sliding directlydepends on the glacier temperature. Based on observation in2009-2012of the glacierAustre Lovénbreen, Svalbard, Arctic. This thesis discusses temperature variationcharacteristics of the glacier active layer, and to discuss the relationship of icetemperature, climate and mass balance. Calculating heat transfer equation by the heattransfer theory and getting ice temperature in the bed depend on Hobbs theory.Themain results are as following:(1) Active layer temperature is relatively high on the glacier Austre Lovénbreen,interannual variability is small and it decreases with depth increasing. Boreholetemperatures at the depth of20m, core E2is-3.0℃, core B2is-2.4℃,core F is-2.55℃.(2) The change rule of glacier active layer temperature include that the annual icetemperature variations come down in every spring at sites B2, the lowest temperatureis-5.53℃in2011,but it’s not have a certain regularity in the time of autumn, and theglacier temperature is no obvious change with time in the spring and autumn at sitesE2, the annual ice temperature variations go up in every spring and its come down inautumn at sites F2,the lowest temperature is-3.534℃in2011.Compared withatmospheric temperature changes, the glacier activities layer temperature changeusually lags, the spring is about6months, the autumn is about4months.(3) On the glacier Austre Lovénbreen, ice temperature has different changecompared to general rule between200m a.s.1. and500m a.s.1.. The ice temperaturegradient decrease and then increase at depth of10-20m throughout the year, the reduction and the increase are-0.2℃/100m,0.4℃/100m, the minimum icetemperature at410m a.s.1.. At depth of0-10m, the maximum ice temperature in thefrontal part of the tongue at sites B2in autumn and the rule of ice temperature havecomplex change at sites E2and F.(4) Average annual temperature (Ta) and ice temperature at the depth of20m (T10)on the glacier Austre Lovénbreen during the period of2009to2011, Ta=T10in theerror range±1℃. There is no simple linear correlation betweenglacier activities layertemperature, annual precipitation and atmospheric temperature, annual precipitationhas a greater influence on activity layer temperature.(5) During the period of2009to2012, the mass balance of the glacier AustreLovénbreen are-0.12m w.e,-0.07m w.e,-0.99m w.e and-0.12m w.e, and theaverage equilibrium line altitude are394.79m,379.16m,562.51m and394.89m. Theyhave the same change rule with activity layer temperature.(6) Base on heat transfer theory and ice temperature data in2009, glacier activitieslayer heat transfer condition are analyzed. Heat transfer dominates in the under4mon glacier AustreLovénbreen, the condition is very complex in the upper4m, glaciersurface have mixture of ice and water in the autumn. The decrease rate of icetemperature is maximum value, with amplitude increasing with depth, γ=0.0714℃/m,the temperature change different in the ice layer, Ts=16.54,β=6.4. At the depth of54m,82m,72m, ablation area, balance area and accumulation area get melt and meltingpoint is-0.05℃、-0.06℃、-0.06℃.