Surface energy balance and meltwater production for a Dry Valley glacier,
                  Taylor Valley, Antarctica

Lewis, Karen J.; Fountain, Andrew G.; Dana, Gayle L.

doi:10.3189/1998aog27-1-603-609

Cited by 61 publications

(80 citation statements)

References 7 publications

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“…During warm austral summer months, this accumulated supply of subsurface ice melts and seeps to the surface, and could generate some of the liquid water we observed. It is not clear, however, whether this source alone could supply the amount of water observed, as loss by sublimation would be quite high (Clow et al, 1988;Lewis et al, 1998;Gooseff et al, 2003). How much melt could be recharged by this process is unknown.…”

Section: Discussionmentioning

confidence: 86%

Solute and isotope geochemistry of subsurface ice melt seeps in Taylor Valley, Antarctica

Harris

Carey

Lyons

et al. 2007

Geological Society of America Bulletin

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The McMurdo Dry Valleys of Antarctica are a polar desert region with watersheds dominated by glacial melt. Recent ground exploration reveals unusual surface-fl ow-seep features not directly supplied by glacial melt. Much of this seep water is potentially derived from permafrost, snow patches, refrozen precipitation accumulated in the subsurface, buried glacier ice, or even groundwater from the deep subsurface. Flow features that lack obvious glacier melt sources were identifi ed in archived aerial photographs of Taylor Valley. This valley was surveyed for extant and extinct seeps, and the locations of geomorphic features in fi ve active seeps were documented. Water samples from seeps were analyzed for major ions and stable isotopes of hydrogen and oxygen. Solute chemistry and isotopic signatures of seeps are distinct from those of nearby streams and glaciers, with the seeps having elevated solute concentrations.All but one seep had water isotopically heavier than water from nearby glaciers and streams, suggesting that seep waters have been substantially modifi ed if they had been derived originally from the same meteoric sources that supply local glaciers and streams. The seeps are important because they compose a previously overlooked component of the desert hydrological cycle. Seep features in the dry valleys are potential terrestrial analogs for the geologically young gullies observed on Mars, which are thought to be evidence of groundwater seepage and surface runoff.

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Section: Discussionmentioning

confidence: 86%

Solute and isotope geochemistry of subsurface ice melt seeps in Taylor Valley, Antarctica

Harris

Carey

Lyons

et al. 2007

Geological Society of America Bulletin

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“…Lewis et al, 1998;Hoffman et al, 2008;MacDonell et al, 2012). Surface energy balance studies have all shown the dominance of sublimation on ice surfaces in this region, and have intimated that not only is melt restricted to approximately two months in the austral summer, but within this period, melting is episodic and spatially constrained (Lewis et al, 1998;Hoffman et al, 2008). Melt at the surface is often restricted to areas where albedo is lowered due to the incorporation of sediment (e.g.…”

Section: Comparison Of Ablation Results With Other Studiesmentioning

confidence: 99%

Meteorological drivers of ablation processes on a cold glacier in the semi-arid Andes of Chile

et al. 2013

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Abstract. Meteorological and surface change measurements collected during a 2.5 yr period are used to calculate surface mass and energy balances at 5324 m a.s.l. on Guanaco Glacier, a cold-based glacier in the semi-arid Andes of Chile. Meteorological conditions are marked by extremely low vapour pressures (annual mean of 1.1 hPa), strong winds (annual mean of 10 m s −1 ), shortwave radiation receipt persistently close to the theoretical site maximum during cloudfree days (mean annual 295 W m −2 ; summer hourly maximum 1354 W m −2 ) and low precipitation rates (mean annual 45 mm w.e.). Snowfall occurs sporadically throughout the year and is related to frontal events in the winter and convective storms during the summer months. Net shortwave radiation provides the greatest source of energy to the glacier surface, and net longwave radiation dominates energy losses. The turbulent latent heat flux is always negative, which means that the surface is always losing mass via sublimation, which is the main form of ablation at the site. Sublimation rates are most strongly correlated with net shortwave radiation, incoming shortwave radiation, albedo and vapour pressure. Low glacier surface temperatures restrict melting for much of the period, however episodic melting occurs during the austral summer, when warm, humid, calm and high pressure conditions restrict sublimation and make more energy available for melting. Low accumulation (131 mm w.e. over the period) and relatively high ablation (1435 mm w.e.) means that mass change over the period was negative (−1304 mm w.e.), which continued the negative trend recorded in the region over the last few decades.

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“…Second, subsurface melting occurs during windy, sunny days by a solid-state greenhouse effect (17,18), even with air temperatures below freezing. In addition, turbulent heat transfer in the Dry Valleys is relatively large and keeps ice surfaces cool (18,19). Thus, a drop in wind speed reduces latent and sensible heat losses such that ablation shifts from sublimation-dominated to melt-dominated (increases in downslope winds also can warm the valleys to melting temperatures, but such winds are infrequent in summer when melting takes place).…”

Section: Discussionmentioning

confidence: 99%

Antarctic lakes suggest millennial reorganizations of Southern Hemisphere atmospheric and oceanic circulation

Hall

Denton

Fountain

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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The phasing of millennial-scale oscillations in Antarctica relative to those elsewhere in the world is important for discriminating among models for abrupt climate change, particularly those involving the Southern Ocean. However, records of millennial-scale variability from Antarctica dating to the last glacial maximum are rare and rely heavily on data from widely spaced ice cores, some of which show little variability through that time. Here, we present new data from closed-basin lakes in the Dry Valleys region of East Antarctica that show high-magnitude, high-frequency oscillations in surface level during the late Pleistocene synchronous with climate fluctuations elsewhere in the Southern Hemisphere. These data suggest a coherent Southern Hemisphere pattern of climate change on millennial time scales, at least in the Pacific sector, and indicate that any hypothesis concerning the origin of these events must account for synchronous changes in both high and temperate latitudes.

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Surface energy balance and meltwater production for a Dry Valley glacier, Taylor Valley, Antarctica

Cited by 61 publications

References 7 publications

Solute and isotope geochemistry of subsurface ice melt seeps in Taylor Valley, Antarctica

Solute and isotope geochemistry of subsurface ice melt seeps in Taylor Valley, Antarctica

Meteorological drivers of ablation processes on a cold glacier in the semi-arid Andes of Chile

Antarctic lakes suggest millennial reorganizations of Southern Hemisphere atmospheric and oceanic circulation

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