02254nas a2200217   4500008004100000245009400041210006900135260001200204300000600216490000700222520158800229653002601817653002401843653001901867653002401886653001801910100002301928700002101951700002201972856004201994       2025                        eng d00aRethinking the lake history of Taylor Valley, Antarctica during the Ross Sea I glaciation0 aRethinking the lake history of Taylor Valley Antarctica during t  c01/2025  a90 v153 a<p>The Ross Sea I glaciation, marked by the northward advance of the Ross Ice Sheet (RIS) in the Ross Sea, east Antarctica, corresponds with the last major expansion of the West Antarctic Ice Sheet during the last glacial period. During its advance, the RIS was grounded along the southern Victoria Land coast, completely blocking the mouths of several of the McMurdo Dry Valleys (MDVs). Several authors have proposed that very large paleolakes, proglacial to the RIS, existed in many of the MDVs. Studies of these large paleolakes have been key in the interpretation of the regional landscape, climate, hydrology, and glacier and ice sheet movements. By far the most studied of these large paleolakes is Glacial Lake Washburn (GLW) in Taylor Valley. Here, we present a comprehensive review of literature related to GLW, focusing on the waters supplying the paleolake, signatures of the paleolake itself, and signatures of past glacial movements that controlled the spatial extent of GLW. We find that while a valley-wide proglacial lake likely did exist in Taylor Valley during the early stages of the Ross Sea I glaciation, during later stages two isolated lakes occupied the eastern and western sections of the valley, confined by an expansion of local alpine glaciers. Lake levels above ~140 m asl were confined to western Taylor Valley, and major lake level changes were likely driven by RIS movements, with climate variables playing a more minor role. These results may have major implications for our understanding of the MDVs and the RIS during the Ross Sea I glaciation.</p>10aGlacial Lake Washburn10aMcMurdo Dry Valleys10aRoss Ice Sheet10aRoss Sea glaciation10aTaylor Valley1 aStone, Michael, S.1 aDoran, Peter, T.1 aMyers, Krista, F.  uhttps://www.mdpi.com/2076-3263/15/1/901966nas a2200253   4500008004100000022001400041245010100055210006900156260001200225490000700237520119400244653001701438653001301455653002401468653000901492653000901501653002101510100002301531700002401554700002201578700002001600700002101620856007101641       2024                        eng d  a1523-043000aMeasuring and modelling functional moat area in perennially ice-covered Lake Fryxell, Antarctica0 aMeasuring and modelling functional moat area in perennially icec  c10/20240 v563 a<p>The perennially ice-covered lakes of the McMurdo Dry Valleys (MDVs), Antarctica, are an important reservoir of liquid water in an arid and largely frozen environment. During the austral summer, the margins of these ice covers melt, forming a &ldquo;moat&rdquo; of liquid water and thin ice, allowing exchange between lake waters and the atmosphere to occur and serving as an interface between lake, soil, and stream ecosystems. The size of these moats varies from year to year. Here, we have established the first published record of moat area changes at MDVs&rsquo; Lake Fryxell through time using manual traces of the moat as observed via satellite imagery. We have also tested a semi-automated approach for measuring moat area and found that it consistently underestimated the manual record, which we suspect may be due to the lower spatial resolution of images used in this versus the manual approach. Finally, we developed a predictive model based on readily available climate data, allowing moat area to be predicted beyond the limits of the satellite-based records. We found that functional moat area varies annually, potentially influencing ecosystem processes in the moats.</p>10aLake Fryxell10alake ice10aMcMurdo Dry Valleys10amoat10aNDWI10apredictive model1 aStone, Michael, S.1 aSalvatore, Mark, R.1 aDugan, Hilary, A.1 aMyers, Madeline1 aDoran, Peter, T.  uhttps://www.tandfonline.com/doi/full/10.1080/15230430.2024.240662602505nas a2200325   4500008004100000022001400041245012700055210006900182260001200251300001800263490000800281520146500289653001701754653003701771653002401808653002401832100002701856700002101883700002301904700002201927700002201949700002501971700002001996700002202016700002202038700002202060700002202082700001402104856006102118       2023                        eng d  a2169-900300aCauses and characteristics of electrical resistivity variability in shallow (<4 m) soils in Taylor Valley, East Antarctica0 aCauses and characteristics of electrical resistivity variability  c02/2023  ae2022JF0066960 v1283 a<p>Airborne electromagnetic surveys collected in December 2011 and November 2018 and three soil sampling transects were used to analyze the spatial heterogeneity of shallow (&lt;4 m) soil properties in lower Taylor Valley (TV), East Antarctica. Soil resistivities from 2011 to 2018 ranged from &sim;33 Ωm to &sim;3,500 Ωm with 200 Ωm assigned as an upper boundary for brine-saturated sediments. Elevations below &sim;50 m above sea level (masl) typically exhibit the lowest resistivities with resistivity increasing at high elevations on steeper slopes. Soil water content was empirically estimated from electrical resistivities using Archie&#39;s Law and range from &sim;&lt;1% to &sim;68% by volume. An increase in silt- and clay-sized particles at low elevations increases soil porosity but decreases hydraulic conductivity, promoting greater residence times of soil water at low elevations near Lake Fryxell. Soil resistivity variability between 2011 and 2018 shows soils at different stages of soil freeze-thaw cycles, which are caused predominantly by solar warming of soils as opposed to air temperature. This study furthers the understanding of the hydrogeologic structure of the shallow subsurface in TV and identifies locations of soils that are potentially prone to greater rates of thaw and resulting ecosystem homogenization of soil properties from projected increases in hydrological connectivity across the region over the coming decades.</p>10aactive layer10aairborne electromagnetic surveys10aMcMurdo Dry Valleys10apermafrost dynamics1 aGutterman, William, S.1 aDoran, Peter, T.1 aVirginia, Ross, A.1 aBarrett, John, E.1 aMyers, Krista, F.1 aTulaczyk, Slawek, M.1 aFoley, Neil, T.1 aMikucki, Jill, A.1 aDugan, Hilary, A.1 aGrombacher, Denys1 aBording, Thue, S.1 aAuken, E.  uhttps://onlinelibrary.wiley.com/doi/10.1029/2022JF00669601961nas a2200217   4500008004100000245010100041210006900142260001200211300001200223490000700235520124400242653003001486653001101516653002401527653001501551653002101566100002001587700002101607700002201628856009301650       2022                        eng d00aValley-floor snowfall in Taylor Valley, Antarctica, from 1995 to 2017: Spring, summer and autumn0 aValleyfloor snowfall in Taylor Valley Antarctica from 1995 to 20  c08/2022  a325-3350 v343 a<p>We present an analysis of the 20 year snowfall dataset in Taylor Valley and the results of a new snow cover monitoring study. Snowfall has been measured at four sites in Taylor Valley from 1995 to 2017. We focus on valley-floor snowfall when wind does not exceed 5 m s<sup>-1</sup>, and we exclude winter from our analysis due to poor data quality. Snowfall averaged 11 mm water equivalent (w.e.) from 1995 to 2017 across all stations and ranged from 1 to 58 mm w.e. Standard deviations ranged from 3 to 17 mm w.e., highlighting the strong interannual variability of snowfall in Taylor Valley. During spring and autumn there is a spatial gradient in snowfall such that the coast received twice as much snowfall as more central and inland stations. We identified a changepoint in 2007 from increasing snowfall (3 mm w.e. yr<sup>-1</sup>) to decreasing snowfall (1 mm w.e. yr<sup>-1</sup>), which coincides with a shift from decreasing temperature to no detectable temperature trend. Daily camera imagery from 2007 to 2017 augments the snowfall measurements. The camera imagery revealed a near tripling of the average number of days with snow cover from 37 days between 2006 and 2012 to 106 days with snow cover between 2012 and 2017.</p>10aautomated weather station10acamera10aMcMurdo Dry Valleys10asnow cover10asnow persistence1 aMyers, Madeline1 aDoran, Peter, T.1 aMyers, Krista, F.  uhttps://www.cambridge.org/core/product/identifier/S0954102022000256/type/journal_article02119nas a2200217   4500008004100000245007600041210006900117260001200186520131800198653001101516653003001527653002801557653002201585653002401607653001201631653001801643100002401661700002101685700002001706856017501726       2020                        eng d00aGIS tool to predict photosynthetically active radiation in a Dry Valley0 aGIS tool to predict photosynthetically active radiation in a Dry  c04/20203 a<p>Understanding primary productivity is a core research area of the National Science Foundation&#39;s Long-Term Ecological Research Network. This study presents the development of the GIS-based Topographic Solar Photosynthetically Active Radiation (T-sPAR) toolbox for Taylor Valley. It maps surface photosynthetically active radiation using four meteorological stations with ~20 years of data. T-sPAR estimates were validated with ground-truth data collected at Taylor Valley&#39;s major lakes during the 2014&ndash;15 and 2015&ndash;16 field seasons. The average daily error ranges from 0.13 mol photons m<sup>-2</sup> day<sup>-1</sup> (0.6%) at Lake Fryxell to 3.8 mol photons m<sup>-2</sup> day<sup>-1</sup> (5.8%) at Lake Hoare. We attribute error to variability in terrain and sun position. Finally, a user interface was developed in order to estimate total daily surface photosynthetically active radiation for any location and date within the basin. T-sPAR improves upon existing toolboxes and models by allowing for the inclusion of a statistical treatment of light attenuation due to cloud cover. The T-sPAR toolbox could be used to inform biological sampling sites based on radiation distribution, which could collectively improve estimates of net primary productivity, in some cases by up to 25%.</p>10aArcMap10aautomated weather station10adigital elevation model10aice-covered lakes10aMcMurdo Dry Valleys10aR model10aTaylor Valley1 aAcosta, Dimitri, R.1 aDoran, Peter, T.1 aMyers, Madeline  uhttps://www.cambridge.org/core/journals/antarctic-science/article/gis-tool-to-predict-photosynthetically-active-radiation-in-a-dry-valley/BD0BE4FF6A8F3DAAF32D69879728707802215nas a2200205   4500008004100000245009200041210006900133260004000202490001000242520158200252653001501834653001001849653001301859653002401872653001601896653001601912100002201928700002101950856003801971       2014                        eng d00aGeophysics, Water Balance, and History of Thick Perennial Ice Covers on Antarctic Lakes0 aGeophysics Water Balance and History of Thick Perennial Ice Cove  aChicago, ILbUniversity of Illinois0 vPh.D.3 a<p>Antarctic lakes are studied as sentinels of future change, for paleolimnological records contained in the sediments, and as habitats for the simple food webs that can exist in inhospitable environments. Understanding how lakes are formed and are sustained in response to landscape and climate conditions is critical in addressing the aforementioned research themes. This thesis is governed by the overarching hypothesis that an understanding of hydrologic and sediment transport processes associated with lake ice formation and preservation can be used to reveal past climatic changes, and further our awareness of current changes in climate and water balance in the McMurdo Dry Valleys of Antarctica. The first chapter focuses on water loss from closed basin lakes in Taylor Valley, Antarctica, and presents updated estimates of sublimation and ablation rates from long-term empirical measurements. The second and third chapters address the formation of Lake Vida, Antarctica. The former investigates the accretion of a 27 m ice cover, and considers the origin of thick sediment layers in the ice cover, and the latter uses two geophysical methods to quantify the extent and volume of the brine network in the subsurface beneath the lake. The results presented herein advance the study of hydrogeology in continuous permafrost, provide additional evidence for fluctuating climate states in the McMurdo Dry Valleys throughout the mid to late Holocene, and provide a case study for the preservation of water in a cold, desert environment analogous to neighboring planets.</p>10aAntarctica10abrine10alake ice10aMcMurdo Dry Valleys10apolar lakes10asublimation1 aDugan, Hilary, A.1 aDoran, Peter, T.  uhttp://hdl.handle.net/10027/19407