Snow in the McMurdo Dry Valleys, Antarctica

Fountain, Andrew G.; Nylen, Thomas; Monaghan, Andrew J.; Basagic, Hassan J.; Bromwich, David H.

doi:10.1002/joc.1933

Cited by 239 publications

(279 citation statements)

References 39 publications

Supporting

Mentioning

259

Contrasting

Order By: Relevance

“…In this hyperarid polar environment, meltwater is derived from snow-free ("blue-ice"), glacier ablation zones. Snow reflects ∼90% of incoming solar energy and, in the current environment, contributes little to runoff, because it largely sublimates (13)(14)(15). Moreover, snow also depresses surface melt (16).…”

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.

Self Cite

View full text Add to dashboard Cite

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.

show abstract

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.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Annual soil surface temperatures around the lake average Ϫ18.4°C, with only 25.5 days above freezing occurring each year (14). The amount of precipitation at Lake Fryxell is 20 to 37 mm annually (30); however, sublimation rates throughout the MDV are significantly greater than precipitation inputs (31). Liquid water inputs occur during a brief glacial melt period during the austral summer due to increased temperatures and solar radiation (32).…”

Section: Methodsmentioning

confidence: 99%

Soil Microbial Responses to Increased Moisture and Organic Resources along a Salinity Gradient in a Polar Desert

Horn

Okie

Buelow³

et al. 2014

Appl Environ Microbiol

175

102

View full text Add to dashboard Cite

dMicrobial communities in extreme environments often have low diversity and specialized physiologies suggesting a limited resistance to change. The McMurdo Dry Valleys (MDV) are a microbially dominated, extreme ecosystem currently undergoing climate change-induced disturbances, including the melting of massive buried ice, cutting through of permafrost by streams, and warming events. These processes are increasing moisture across the landscape, altering conditions for soil communities by mobilizing nutrients and salts and stimulating autotrophic carbon inputs to soils. The goal of this study was to determine the effects of resource addition (water/organic matter) on the composition and function of microbial communities in the MDV along a natural salinity gradient representing an additional gradient of stress in an already extreme environment. Soil respiration and the activity of carbon-acquiring extracellular enzymes increased significantly (P < 0.05) with the addition of resources at the low-and moderate-salinity sites but not the high-salinity site. The bacterial community composition was altered, with an increase in Proteobacteria and Firmicutes with water and organic matter additions at the low-and moderate-salinity sites and a near dominance of Firmicutes at the high-salinity site. Principal coordinate analyses of all samples using a phylogenetically informed distance matrix (UniFrac) demonstrated discrete clustering among sites (analysis of similarity [ANOSIM], P < 0.05 and R > 0.40) and among most treatments within sites. The results from this experimental work suggest that microbial communities in this environment will undergo rapid change in response to the altered resources resulting from climate change impacts occurring in this region.

show abstract

“…2) and the driest cold place on Earth (Marchant et al 1996). The precipitation, exclusively snow is often less than 10 mm water-equivalent (weq) per year, ranging from 3 mm to less than 100 mm in the location closer to the sea (Fountain et al 2009). The Dry Valleys are located within the Transantarctic Mountains in the Southern part of Victoria Land, close to the western coast of McMurdo Sound (between 160°E and 164°E longitude and 76°S and 78°S latitude).…”

Section: Antarctic Mcmurdo Dry Valleysmentioning

confidence: 99%

Earth as a Tool for Astrobiology—A European Perspective

et al. 2017

View full text Add to dashboard Cite

Scientists use the Earth as a tool for astrobiology by analyzing planetary field analogues (i.e. terrestrial samples and field sites that resemble planetary bodies in our Solar System). In addition, they expose the selected planetary field analogues in simulation chambers to conditions that mimic the ones of planets, moons and Low Earth Orbit (LEO) space conditions, as well as the chemistry occurring in interstellar and cometary ices. This paper reviews the ways the Earth is used by astrobiologists: (i) by conducting planetary field analogue studies to investigate extant life from extreme environments, its metabolisms, adaptation strategies and modern biosignatures; (ii) by conducting planetary field analogue studies to investigate extinct life from the oldest rocks on our planet and its biosignatures; (iii) by exposing terrestrial samples to simulated space or planetary environments and producing a sample analogue to investigate changes in minerals, biosignatures and microorganisms. The European Space Agency (ESA) created a topical team in 2011 to investigate recent activities using the Earth as a tool for astrobiology and to formulate recommendations and scientific needs to improve ground-based astrobiological research. Space is an important tool for astrobiology (see Horneck et al. in Astrobiology, 16:201-243, 2016;Cottin et al., 2017), but access to space is limited. Complementing research on Earth provides fast access, more replications and higher sample throughput. The major conclusions of the topical team and suggestions for the future include more scientifically qualified calls for field campaigns with planetary analogy, and a centralized point of contact at ESA or the EU for the organization of a survey of such expeditions. An improvement of the coordinated logistics, infrastructures and funding system supporting the combination of field work with planetary simulation investigations, as well as an optimization of the scientific return and data processing, data storage and data distribution is also needed. Finally, a coordinated EU or ESA education and outreach program would improve the participation of the public in the astrobiological activities.

show abstract

Snow in the McMurdo Dry Valleys, Antarctica

Cited by 239 publications

References 39 publications

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

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

Soil Microbial Responses to Increased Moisture and Organic Resources along a Salinity Gradient in a Polar Desert

Earth as a Tool for Astrobiology—A European Perspective

Contact Info

Product

Resources

About