Modeling the thickness of perennial ice covers on stratified lakes of the Taylor Valley, Antarctica
نویسندگان
چکیده
A 1-D ice cover model was developed to predict and constrain drivers of long-term ice thickness trends in chemically stratified lakes of Taylor Valley, Antarctica. The model is driven by surface radiative heat fluxes and heat fluxes from the underlying water column. The model successfully reproduced 16 a (between 1996 and 2012) of ice thickness changes for the west lobe of Lake Bonney (average ice thickness= 3.53 m) and Lake Fryxell (average ice thickness= 4.22 m). Long-term ice thickness trends require coupling with the thermal structure of the water column. The heat stored within the temperature maximum of lakes exceeding a liquid water column depth of 20 m can either impede or facilitate ice thickness change depending on the predominant climatic trend (cooling or warming). As such, shallow (<20 m deep water columns) perennially ice-covered lakes without deep temperature maxima are more sensitive indicators of climate change. The long-term ice thickness trends are a result of surface energy flux and heat flux from the deep temperature maximum in the water column, the latter of which results from absorbed solar radiation.
منابع مشابه
Hydrological Controls on Ecosystem Dynamics in Lake Fryxell, Antarctica
The McMurdo Dry Valleys constitute the largest ice free area of Antarctica. The area is a polar desert with an annual precipitation of ∼ 3 cm water equivalent, but contains several lakes fed by glacial melt water streams that flow from four to twelve weeks of the year. Over the past ∼20 years, data have been collected on the lakes located in Taylor Valley, Antarctica as part of the McMurdo Dry ...
متن کاملLimnol. Oceanogr., 44(2), 1999, 447–454
Geophysical and ecological dynamics within lakes of the McMurdo Dry Valleys, Antarctica, are controlled by the presence of permanent ice covers. Despite the importance of the permanent ice cover, there have been no studies that have examined specific couplings between changes in the geophysical properties of the ice covers and dynamic ecological processes within the underlying water column. Her...
متن کاملDistribution of Siliceous-Walled Algae in Taylor Valley, Antarctica Lakes
The McMurdo Dry Valleys of Antarctica are a unique environment characterized by extreme lows in temperature and precipitation, which supports a low diversity microbial and multicellular fauna and flora. Terrestrial biomass is largely limited to soil microbes and mosses, while perennially ice-covered lakes host aerobic and anaerobic microbial communities, algae, and a low diversity eukaryotic fa...
متن کاملSediment Melt-Migration Dynamics in Perennial Antarctic Lake Ice
We examined sediment melt-migration dynamics in the ice cover of Lake Fryxell, Taylor Valley, McMurdo Dry Valleys, Antarctica, using a combination of laboratory experiments, field observations, and modeling. The specific objectives were to determine the thermal conditions required for sediment melt and how sediment migration rates vary with meteorological forcings and ice microstructure. These ...
متن کاملImpact of Episodic Warming Events on the Physical, Chemical and Biological Relationships of Lakes in the McMurdo Dry Valleys, Antarctica
Lakes in the Taylor Valley, Antarctica were investigated to determine the impact of a significant air temperature warming event that occurred during the austral summer of 2001–2002. The warming in the valleys caused an increase in glacial run-off, record stream discharge, an increase in lake levels, and thinning of the permanent ice covers. These changes in the physical environment drove subseq...
متن کامل