The seasonal evolution of albedo across glaciers and the surrounding landscape of the Taylor Valley, Antarctica

Abstract. The McMurdo Dry Valleys (MDVs) of Antarctica are a polar desert ecosystem consisting of alpine glaciers, ice-covered lakes, streams, and expanses of vegetation-free rocky soil. Because average summer temperatures are close to 0 ∘C, the MDV ecosystem in general, and glacier melt dynamics in particular, are both closely linked to the energy balance. A slight increase in incoming radiation or change in albedo can have large effects on the timing and volume of meltwater. However, the seasonal evolution or spatial variability of albedo in the valleys has yet to fully characterized. In this study, we aim to understand the drivers of landscape albedo change within and across seasons. To do so, a box with a camera, GPS, and shortwave radiometer was hung from a helicopter that flew transects four to five times a season along Taylor Valley. Measurements were repeated over three seasons. These data were coupled with incoming radiation measured at six meteorological stations distributed along the valley to calculate the distribution of albedo across individual glaciers, lakes, and soil surfaces. We hypothesized that albedo would decrease throughout the austral summer with ablation of snow patches and increasing sediment exposure on the glacier and lake surfaces. However, small snow events (<6 mm water equivalent) coupled with ice whitening caused spatial and temporal variability of albedo across the entire landscape. Glaciers frequently followed a pattern of increasing albedo with increasing elevation, as well as increasing albedo moving from east to west laterally across the ablation zone. We suggest that spatial patterns of albedo are a function of landscape morphology trapping snow and sediment, longitudinal gradients in snowfall magnitude, and wind-driven snow redistribution from east to west along the valley. We also compare our albedo measurements to the MODIS albedo product and found that overall the data have reasonable agreement. The mismatch in spatial scale between these two datasets results in variability, which is reduced after a snow event due to albedo following valley-scale gradients of snowfall magnitude. These findings highlight the importance of understanding the spatial and temporal variability in albedo and the close coupling of climate and landscape response. This new understanding of landscape albedo can constrain landscape energy budgets, better predict meltwater generation on from MDV glaciers, and how these ecosystems will respond to changing climate at the landscape scale.

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Geochemistry of contrasting stream types, Taylor Valley, Antarctica

Geological Society of America Bulletin ◽

10.1130/b35479.1 ◽

2020 ◽

Vol 133 (1-2) ◽

pp. 425-448

Author(s):

Russell S. Harmon ◽

Deborah L. Leslie ◽

W. Berry Lyons ◽

Kathleen A. Welch ◽

Diane M. McKnight

Keyword(s):

Dissolved Oxygen ◽

Austral Summer ◽

Mineral Dissolution ◽

Silicate Mineral ◽

Cation Composition ◽

Taylor Valley ◽

Low Concentrations ◽

Hyporheic Zones ◽

Dry Valley ◽

Geochemical Fingerprint

Abstract The McMurdo Dry Valley region is the largest ice-free area of Antarctica. Ephemeral streams flow here during the austral summer, transporting glacial meltwater to perennially ice-covered, closed basin lakes. The chemistry of 24 Taylor Valley streams was examined over the two-decade period of monitoring from 1993 to 2014, and the geochemical behavior of two streams of contrasting physical and biological character was monitored across the seven weeks of the 2010–2011 flow season. Four species dominate stream solute budgets: HCO3–, Ca2+, Na+, and Cl–, with SO42–, Mg2+, and K+ present in significantly lesser proportions. All streams contain dissolved silica at low concentrations. Across Taylor Valley, streams are characterized by their consistent anionic geochemical fingerprint of HCO3 > Cl > SO4, but there is a split in cation composition between 14 streams with Ca > Na > Mg > K and 10 streams with Na > Ca > Mg > K. Andersen Creek is a first-order proglacial stream representative of the 13 short streams that flow <1.5 km from source to gage. Von Guerard is representative of 11 long streams 2–7 km in length characterized by extensive hyporheic zones. Both streams exhibit a strong daily cycle for solute load, temperature, dissolved oxygen, and pH, which vary in proportion to discharge. A well-expressed diurnal co-variation of pH with dissolved oxygen is observed for both streams that reflects different types of biological control. The relative consistency of Von Guerard composition over the summer flow season reflects chemostatic regulation, where water in transient storage introduced during times of high streamflow has an extended opportunity for water-sediment interaction, silicate mineral dissolution, and pore-water exchange.

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A temperature-index model of stream flow at below-freezing temperatures in Taylor Valley, Antarctica

Annals of Glaciology ◽

10.3189/172756405781813519 ◽

2005 ◽

Vol 40 ◽

pp. 76-82 ◽

Cited By ~ 29

Author(s):

Amy F. Ebnet ◽

Andrew G. Fountain ◽

Thomas H. Nylen ◽

Diane M. Mcknight ◽

Christopher L. Jaros

Keyword(s):

Melting Rate ◽

Coefficient Of Determination ◽

Dry Valleys ◽

The South ◽

Index Model ◽

The North ◽

Taylor Valley ◽

Air Temperatures ◽

Glacial Runoff ◽

Summer Temperatures

AbstractWe model runoff from glaciers in the McMurdo Dry Valleys, Antarctica, with summer (December–January) average air temperatures from 1990 to 2002 for the purpose of estimating decades- to millennial-scale glacial runoff into Lakes Fryxell, Hoare and Bonney. The relationship between summer temperatures and melt is found to be exponential near the melting temperature. We propose a variety of simple models that are calibrated using measured discharge from a number of streams draining from ten glaciers in Taylor Valley. The surface melting rate is constrained by mass-balance measurements from four of the glaciers. A model based solely on temperature produced good results (coefficient of determination, r2 = 0.71) for the south-facing glaciers, but poor results for the north-facing glaciers (r2 < 0). The inclusion of a solar radiation index increased the modeled melt from the north-facing glaciers and thus improved the results (r2 = 0.73) for the north-facing glaciers, with little change from the south-facing glaciers. Including a wind index did not improve the correlation between modeled and measured runoff.

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Groundwater seeps in Taylor Valley Antarctica: an example of a subsurface melt event

Annals of Glaciology ◽

10.3189/172756405781813609 ◽

2005 ◽

Vol 40 ◽

pp. 200-206 ◽

Cited By ~ 55

Author(s):

W. Berry Lyons ◽

Kathleen A. Welch ◽

Anne E. Carey ◽

Peter T. Doran ◽

Diana H. Wall ◽

...

Keyword(s):

Austral Summer ◽

Geochemical Data ◽

Decadal Time Scale ◽

Stream Flows ◽

Unusual Event ◽

The North ◽

Taylor Valley ◽

Dry Valley ◽

Geochemical Models ◽

Sources Of Solutes

AbstractThe 2001/02 austral summer was the warmest summer on record in Taylor Valley, Antarctica, (∼78° S) since continuous records of temperature began in 1985. The highest stream-flows ever recorded in the Onyx River, Wright Valley, were also recorded that year (the record goes back to the 1969/70 austral summer). In early January 2002, a groundwater seep was observed flowing in the southwest portion of Taylor Valley. This flow has been named ‘Wormherder Creek’ (WHC) and represents an unusual event, probably occurring on a decadal time-scale. The physical characteristics of this feature suggest that it may have flowed at other times in the past. Other groundwater seeps, emanating from the north-facing slope of Taylor Valley, were also observed. Little work has been done previously on these very ephemeral seeps, and the source of water is unknown. These features, resembling recently described features on Mars, represent the melting of subsurface ice. The Martian features have been interpreted as groundwater seeps. In this paper we compare the chemistry of the WHC groundwater seep to that of the surrounding streams that flow every austral summer. The total dissolved solids content of WHC was ∼6 times greater than that of some nearby streams. The Na : Cl and SO4 : Cl ratios of the seep waters are higher than those of the streams, but the Mg : Cl and HCO3 : Cl ratios are lower, indicating different sources of solutes to the seeps compared to the streams. The enrichment of Na and SO4 relative to Cl may suggest significant dissolution of mirabilite within the previously unwetted soil. The proposed occurrence of abundant mirabilite in higher-elevation soils of the dry valley region agrees with geochemical models developed, but not tested, in the late 1970s. The geochemical data demonstrate that these seeps could be important in ‘rinsing’ the soils by dissolving and redistributing the long-term accumulation of salts, and perhaps improving habitat suitability for soil biota. The H4SiO4 concentration is 2–3 times greater in WHC than in the surrounding streams, indicating a large silicate-weathering component in the seep waters.

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Supplementary material to "The seasonal evolution of albedo across glaciers and the surrounding landscape of the Taylor Valley, Antarctica"

10.5194/tc-2019-146-supplement ◽

2019 ◽

Author(s):

Anna Bergstrom ◽

Michael Gooseff ◽

Madeline Myers ◽

Peter T. Doran

Keyword(s):

Seasonal Evolution ◽

Taylor Valley ◽

Supplementary Material ◽

Surrounding Landscape

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Antarctic Permafrost Degassing Revealed By Extensive Soil Gas and Co2 Flux Survey in Taylor Valley

10.21203/rs.3.rs-1154287/v1 ◽

2021 ◽

Author(s):

Livio Ruggiero ◽

Alessandra Sciarra ◽

Adriano Mazzini ◽

Fabio Florindo ◽

Gary Wilson ◽

...

Keyword(s):

Austral Summer ◽

Soil Surface ◽

Co2 Flux ◽

Permafrost Degradation ◽

Dry Valleys ◽

Climate Conditions ◽

Taylor Valley ◽

C Cycle ◽

High Concentrations ◽

Soil Gases

Abstract McMurdo Dry Valleys comprise 10% of the ice-free soil surface areas in Antarctica. Permafrost stability plays an important role in C-cycle as it potentially stores considerable quantities of greenhouse gases. While the geomorphology of the Dry Valleys reflects a long history of changing climate conditions, comparison with the rapidly warming Northern polar region suggests that future climate and ecosystems may change more rapidly from permafrost degradation. In Austral summer 2019/2020 a comprehensive sampling of soil gases and CO2 flux measurements was undertaken in the Taylor Valley, with the aims to identify potential presence of soil gases in the active layer. The results obtained show high concentrations of CH4, CO2, He and an increasing CO2 flux rate. We identify the likely source of the gas to be from dissolved gases in deep brine moving from inland (potentially underneath the Antarctic Ice Sheet) to the coast at depth beneath the permafrost layer.

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Inland diatoms from the McMurdo Dry Valleys and James Ross Island, Antarctica

Botany ◽

10.1139/b08-100 ◽

2008 ◽

Vol 86 (12) ◽

pp. 1378-1392 ◽

Cited By ~ 36

Author(s):

R. M.M. Esposito ◽

S. A. Spaulding ◽

D. M. McKnight ◽

B. Van de Vijver ◽

K. Kopalová ◽

...

Keyword(s):

Austral Summer ◽

Mcmurdo Dry Valleys ◽

Size Spectrum ◽

Dry Valleys ◽

Dominant Group ◽

Lower Range ◽

Glacial Ice ◽

Dry Valley ◽

James Ross Island ◽

Harsh Conditions

Diatom taxa present in the inland streams and lakes of the McMurdo Dry Valleys and James Ross Island, Antarctica, are presented in this paper. A total of nine taxa are illustrated, with descriptions of four new species ( Luticola austroatlantica sp. nov., Luticola dolia sp. nov., Luticola laeta sp. nov., Muelleria supra sp. nov.). In the perennially ice-covered lakes of the McMurdo Dry Valleys, diatoms are confined to benthic mats within the photic zone. In streams, diatoms are attached to benthic surfaces and within the microbial mat matrix. One species, L. austroatlantica, is found on James Ross Island, of the southern Atlantic archipelago, and the McMurdo Dry Valleys. The McMurdo Dry Valley populations are at the lower range of the size spectrum for the species. Streams flow for 6–10 weeks during the austral summer, when temperatures and solar radiation allow glacial ice to melt. The diatom flora of the region is characterized by species assemblages favored under harsh conditions, with naviculoid taxa as the dominant group and several major diatom groups conspicuously absent.

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The impact of fossil fuel burning related to scientific activities in the McMurdo Dry Valleys, Antarctica: Revisited

Elem Sci Anth ◽

10.1525/elementa.288 ◽

2018 ◽

Vol 6 ◽

Cited By ~ 1

Author(s):

W. Berry Lyons ◽

Elsa Saelens ◽

Kathleen A. Welch

Keyword(s):

Fossil Fuel ◽

Austral Summer ◽

Dry Valleys ◽

Carbon And Nitrogen ◽

Fossil Fuel Burning ◽

Taylor Valley ◽

Fuel Burning ◽

Field Season ◽

C And N ◽

The Impact

Fossil fuel use associated with scientific activities in the Taylor Valley, Antarctic has been examined to determine the fluxes of particulate organic and elemental carbon and nitrogen as well as NOx for the 2015–2016 austral summer field season. These carbon and nitrogen fluxes are compared to our previously published calculations for the 1997–1998 austral summer. In addition, we compile fossil fuel usage and resulting C and N fluxes from the major field camp in Taylor Valley, Lake Hoare Camp (LHC) from the late 1990’s through 2017. In general, the annual fluxes do vary from year to year, but there is no significant trend, at least during the primary summer field season. There is indication that increasing the length of scientific operations does increase the C and N inputs via fossil fuel burning. This works supports our original results demonstrating that over long periods of time the anthropogenic flux of N from local fossil fuel burning could become quantitatively important in the region. Although the particulate C fluxes remain very low, the recent finding of black carbon in the Taylor Valley landscape indicates more on-going monitoring of the source of this material is merited.

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Review to Bergstrom et al. (2019): "The seasonal evolution of albedo across glaciers and the surrounding landscape of the Taylor Valley, Antarctica" submitted to The Cryosphere.

10.5194/tc-2019-146-rc1 ◽

2019 ◽

Author(s):

Anonymous

Keyword(s):

Seasonal Evolution ◽

Taylor Valley ◽

Surrounding Landscape

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Rock glacier characteristics serve as an indirect record of multiple alpine glacier advances in Taylor Valley, Antarctica

10.5194/tc-2019-135 ◽

2019 ◽

Author(s):

Kelsey Winsor ◽

Kate M. Swanger ◽

Esther Babcock ◽

Rachel D. Valletta ◽

James L. Dickson

Keyword(s):

Ross Sea ◽

Ice Cores ◽

Dry Valleys ◽

Rock Glacier ◽

Alpine Glacier ◽

Glacial Origin ◽

Taylor Valley ◽

Dry Valley ◽

Geochemical Analyses ◽

Ground Penetrating

Abstract. The geomorphic record indicates that alpine glaciers in the McMurdo Dry Valleys of southern Victoria Land, Antarctica appear to advance during interglacial periods in response to ice-free conditions in the Ross Sea. Few records of these advances are preserved and/or subaerially exposed, complicating the interpretations of regional glacier response to climate changes. Here, we present geophysical and geochemical analyses of a rock glacier that originates from icefalls fed by alpine Doran Glacier in central Taylor Valley. The rock glacier exhibits a trend of increased weathering of granitic clasts via ventifaction and grussification down-flow. Meltwater ponds on the rock glacier exhibit variable salinity that ranges from freshwater to higher than seawater, with the highest salinity pond near the rock glacier toe. Ground-penetrating radar analyses reveal the feature to possess a primarily clean ice interior, with layers of englacial debris. Stable isotopic data from three ice cores support a glacial origin for the ice within the rock glacier. These data suggest that the current morphology of the rock glacier is the result of multiple events of increased ice contribution caused by advances of Doran Glacier, which is the main source of the ice that cores the rock glacier. We therefore demonstrate the potential of ice-cored rock glaciers to record multiple advances and retreats of Dry Valley glaciers, permitting the interpretation of glacial responses to Pleistocene and Holocene climate change even where direct records are not present.

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