Long‐term shifts in feedbacks among glacier surface change, melt generation, and runoff, McMurdo Dry Valleys, Antarctica

2021 ◽  
Author(s):  
Anna Bergstrom ◽  
Michael Gooseff ◽  
Andrew Fountain ◽  
Matthew Hoffman
Keyword(s):  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Glacier Surface ◽  
Surface Change ◽  
Melt Generation

Episodic basin-scale soil moisture anomalies associated with high relative humidity events in the McMurdo Dry Valleys, Antarctica

2021 ◽  
pp. 1-15
Author(s):  
Joseph Levy
Keyword(s):  
Soil Moisture ◽  
Relative Humidity ◽  
Mcmurdo Dry Valleys ◽  
Limiting Factor ◽  
High Humidity ◽  
Dry Valleys ◽  
Surface Soils ◽  
Basin Scale ◽  
Soil Reflectance

Abstract Outside of hydrologically wetted active layer soils and humidity-sensitive soil brines, low soil moisture is a limiting factor controlling biogeochemical processes in the McMurdo Dry Valleys. But anecdotal field observations suggest that episodic wetting and darkening of surface soils in the absence of snowmelt occurs during high humidity conditions. Here, I analyse long-term meteorological station data to determine whether soil-darkening episodes are present in the instrumental record and whether they are, in fact, correlated with relative humidity. A strong linear correlation is found between relative humidity and soil reflectance at the Lake Bonney long-term autonomous weather station. Soil reflectance is found to decrease annually by a median of 27.7% in response to high humidity conditions. This magnitude of darkening is consistent with soil moisture rising from typical background values of < 0.5 wt.% to 2–3 wt.%, suggesting that regional atmospheric processes may result in widespread soil moisture generation in otherwise dry surface soils. Temperature and relative humidity conditions under which darkening is observed occur for hundreds of hours per year, but are dominated by episodes occurring between midnight and 07h00 local time, suggesting that wetting events may be common, but are not widely observed during typical diel science operations.

The Mcmurdo Dry Valleys Long‐Term Ecological Rsearch Program: New understanding of the biogeochemistry of the Dry Valley Lakes: A review1

2001 ◽  
Vol 25 (3) ◽  
pp. 202-217 ◽  
Author(s):  
W. Berry Lyons ◽  
Kathleen A. Welch ◽  
John C. Priscu ◽  
Johanna Labourn‐Parry ◽  
Daryl Moorhead ◽  
...  
Keyword(s):  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Dry Valley

Reactivation of a cryptobiotic stream ecosystem in the McMurdo Dry Valleys, Antarctica: A long-term geomorphological experiment

Geomorphology ◽  
2007 ◽  
Vol 89 (1-2) ◽  
pp. 186-204 ◽  
Author(s):  
D.M. McKnight ◽  
C.M. Tate ◽  
E.D. Andrews ◽  
D.K. Niyogi ◽  
K. Cozzetto ◽  
...  
Keyword(s):  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Stream Ecosystem

Long-term experimental warming reduces soil nematode populations in the McMurdo Dry Valleys, Antarctica

2009 ◽  
Vol 41 (10) ◽  
pp. 2052-2060 ◽  
Author(s):  
B.L. Simmons ◽  
D.H. Wall ◽  
B.J. Adams ◽  
E. Ayres ◽  
J.E. Barrett ◽  
...  
Keyword(s):  
Mcmurdo Dry Valleys ◽  
Soil Nematode ◽  
Dry Valleys ◽  
Experimental Warming

scholarly journals Pseudovertical Temperature Profiles Give Insight into Winter Evolution of the Atmospheric Boundary Layer over the McMurdo Dry Valleys of Antarctica

2013 ◽  
Vol 52 (7) ◽  
pp. 1664-1669 ◽  
Author(s):  
Peyman Zawar-Reza ◽  
Marwan Katurji ◽  
Iman Soltanzadeh ◽  
Tanja Dallafior ◽  
Shiyuan Zhong ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Weather Prediction ◽  
Atmospheric Temperature ◽  
Numerical Weather Prediction Model ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Cold Pools ◽  
Routine Monitoring ◽  
Strong Winds

AbstractMeasuring routine vertical profiles of atmospheric temperature is critical in understanding stability and the dynamics of the boundary layer. Routine monitoring in remote areas such as the McMurdo Dry Valleys (MDV) of Antarctica is logistically difficult and expensive. Pseudovertical profiles that were derived from a network of inexpensive ground temperature sensors planted on valley sidewalls (up to 330 m above valley floor), together with data from a weather station and a numerical weather prediction model, provided a long-term climatological description of the evolution of the winter boundary layer over the MDV. In winter, persistent valley cold pools (VCPs) were common, lasting up to 2 weeks. The VCPs were eroded by warm-air advection from aloft associated with strong winds, increasing the temperature of the valley by as much as 25 K. Pseudovertical datasets as described here can be used for model validation.

scholarly journals Evolution of cryoconite holes and their contribution to meltwater runoff from glaciers in the McMurdo Dry Valleys, Antarctica

2004 ◽  
Vol 50 (168) ◽  
pp. 35-45 ◽  
Author(s):  
Andrew G. Fountain ◽  
Martyn Tranter ◽  
Thomas H. Nylen ◽  
Karen J. Lewis ◽  
Derek R. Mueller
Keyword(s):  
Water Levels ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Glacier Surface ◽  
Near Surface ◽  
Ice Melt ◽  
Ice Surface ◽  
Meltwater Runoff ◽  
Hydrologic System ◽  
Chloride Accumulation

AbstractCryoconite holes are water-filled holes in the surface of a glacier caused by enhanced ice melt around trapped sediment. Measurements on the ablation zones of four glaciers in Taylor Valley, Antarctica, show that cryoconite holes cover about 4–6% of the ice surface. They typically vary in diameter from 5 to 145 cm, with depths ranging from 4 to 56 cm. In some cases, huge holes form with 5 m depths and 30 m diameters. Unlike cryoconite holes elsewhere, these have ice lids up to 36 cm thick and melt from within each spring. About one-half of the holes are connected to the near-surface hydrologic system and the remainder are isolated. The duration of isolation, estimated from the chloride accumulation in hole waters, commonly shows ages of several years, with one hole of 10 years. The cryoconite holes in the McMurdo Dry Valleys create a near-surface hydrologic system tens of cm below the ice surface. The glacier surface itself is generally frozen and dry. Comparison of water levels between holes a few meters apart shows independent cycles of water storage and release. Most likely, local freeze–thaw effects control water passage and therefore temporary storage. Rough calculations indicate that the holes generate at least 13% of the observed runoff on the one glacier measured. This hydrologic system represents the transition between a melting ice cover with supraglacial streams and one entirely frozen and absent of water.

scholarly journals The origin of channels on lower Taylor Glacier, McMurdo Dry Valleys, Antarctica, and their implication for water runoff

2005 ◽  
Vol 40 ◽  
pp. 1-7 ◽  
Author(s):  
Robin R. Johnston ◽  
Andrew G. Fountain ◽  
Thomas H. Nylen
Keyword(s):  
Energy Balance ◽  
Water Discharge ◽  
Mcmurdo Dry Valleys ◽  
Equilibrium Geometry ◽  
Water Runoff ◽  
Dry Valleys ◽  
Glacier Surface ◽  
Field Evidence ◽  
Developed Surface ◽  
Taylor Glacier

AbstractWell-developed surface channels on Taylor Glacier, McMurdo Dry Valleys, Antarctica, begin as medial moraines incised as shallow, narrow surface depressions, and retain this geometry for tens of km. Over a distance of 1100 m, the channel geometry dramatically changes, reaching depths >20m and widths >100 m. After rapidly enlarging, the channels appear to evolve toward a new equilibrium geometry. Compared to the glacier surface, the air temperature in the channels is warmer by ∼1.7˚C, wind speed is reduced by ∼2.4ms–1 and net shortwave radiation is greater by ∼14Wm–2. The microclimate in the channel shifts the energy balance towards enhanced melt. Field evidence and energy-balance modeling indicate ablation in the deep channels is ∼4.5 times greater than the local horizontal glacier surface and that melt accounts for ∼99% of the summer ablation, compared to ∼75% on the adjacent horizontal glacier surface. Melt in these channels supplies 65% of the unaccounted water discharge into the neighboring lake. In large part, the channels generate the water they carry, rather than merely route water generated elsewhere.

THE IMPACT OF CLIMATE CHANGE ON LAKE VANDA, MCMURDO DRY VALLEYS, ANTARCTICA

2016 ◽  
Author(s):  
Devin Castendyk ◽  
◽  
Maciej K. Obryk ◽  
Sasha Z. Leidman ◽  
Michael Gooseff ◽  
...  
Keyword(s):  
Climate Change ◽  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Impact Of Climate Change ◽  
The Impact

PRELIMINARY CHARACTERIZATION OF WIND-BLOWN DUST FROM THE MCMURDO DRY VALLEYS OF ANTARCTICA

2016 ◽  
Author(s):  
Melisa A. Diaz ◽  
◽  
Susan A. Welch ◽  
Kathleen A. Welch ◽  
Alia L. Khan ◽  
...  
Keyword(s):  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Preliminary Characterization

ALPINE GLACIER ADVANCE DURING MIS 11 IN THE MCMURDO DRY VALLEYS, ANTARCTICA

2016 ◽  
Author(s):  
Kate M. Swanger ◽  
◽  
Joerg M. Schaefer ◽  
Gisela Winckler
Keyword(s):  
Mcmurdo Dry Valleys ◽  
Dry Valleys ◽  
Alpine Glacier ◽  
Glacier Advance
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