The effects of high meltwater on the limnology of Lake Fryxell and Lake Hoare, Taylor Valley, Antarctica, as shown by dissolved gas, tritium and chlorofluorocarbons
The effects of high meltwater on the limnology of Lake Fryxell and Lake Hoare, Taylor Valley, Antarctica, as shown by dissolved gas, tritium and chlorofluorocarbons
复制标题
高融水对南极洲泰勒谷弗里克塞尔湖和霍尔湖湖沼学的影响，如溶解气体、氚和氯氟烃所示
作者：
C. Dowling;R. Poreda;W. Lyons
南极洲麦克默多干谷封闭盆地常年冰封湖泊中，液态水可利用性的微小变化会对湖泊的水位、水化学和地球化学动力学产生深远的影响。我们已经编制了已发表和未发表的数据溶解气体，氚和氯氟烃（CFCs）的弗里克塞尔湖和霍尔湖，以确定高融水年（2001-02年夏季）对湖泊的影响。溶解气体、氚和氟氯化碳数据表明，流向湖泊表面的淡水脉冲并没有与上层水柱广泛混合。在霍尔湖底部，可测量的CFC和较低的溶解气体值表明，最近的融水可能与底部沃茨混合。这种输运的可能机制是具有c的弱密度流。0.1-1.5%的地表水被向下输送到霍尔湖。这种深水输入，而不是恒定的，可能有显着的影响，随着时间的推移在霍尔湖的底部沃茨的化学。在弗里克塞尔湖，氚和CFC的数据表明，最近的融水没有显着影响底层水化学，因此，弱密度电流可能不存在于弗里克塞尔湖。
Abstract Small changes in the availability of liquid water can have profound effects on the water levels, aqueous chemistry and biogeochemical dynamics of the closed-basin, perennially ice-covered lakes of the McMurdo Dry Valleys, Antarctica. We have compiled the published and unpublished data on dissolved gas, tritium and chlorofluorocarbons (CFCs) for Lake Fryxell and Lake Hoare to determine the effects of a high meltwater year (2001–02 summer) on the lakes. The dissolved gas, tritium and CFC data indicate that the pulse of freshwater that flowed onto the surfaces of the lakes did not mix extensively with the upper water column. At the bottom of Lake Hoare, the measurable CFC and lower dissolved gas values suggest that the recent meltwater may have mixed with bottom waters. The probable mechanism for this transportation is weak density currents with c. 0.1–1.5% surface water being transported downwards in Lake Hoare. This deep water input, while not constant, may have a significant effect on the chemistry of the bottom waters in Lake Hoare over time. In Lake Fryxell, the tritium and CFC data indicate that the recent meltwater did not significantly affect the bottom water chemistry; therefore, weak density currents may not be present in Lake Fryxell.