@article {4994, title = {The hydrologic and geochemical contributions from snow to streamflow in the McMurdo Dry Valleys of Antarctica}, journal = {Hydrological Processes}, volume = {38}, year = {2024}, month = {06/2024}, pages = {e15195}, abstract = {

The glacial meltwater streams in the McMurdo Dry Valleys (MDVs), Antarctica only flow during the austral summer and contain abundant algal mats which grow at the onset of flow. Their relative abundance in stream channels of this polar desert make the streams biogeochemical hot spots. The MDVs receive minimal precipitation as snow, which is redistributed by wind and deposited in distinct locations, some of which become persistent snow patches each year. Previous studies identified that MDV streamflow comes from a combination of glacier ice and snow, although snow was assumed to contribute little to the overall water budget. This study uses a combination of satellite imagery, terrain analysis, and field measurements to determine where snow patches accumulate and persist across MDV watersheds, and to quantify the potential hydrologic and biogeochemical contributions of snow patches to streams. Watersheds near the coast have the highest snow-covered area and longest snow persistence. Many of these snow patches accumulate within the stream channels, which results in the potential to contribute to streamflow. During the summer of 2021\–2022, stream channel snow patches had the potential to contribute anywhere between \<1\% and 90\% of the total annual discharge in Lake Fryxell Basin streams, and may increase with different hydrometeorological conditions. On average the potential inputs from snow patches to streamflow was between 12\% and 25\% of the annual discharge during the 2021\–2022 season, as determined by snow area and SWE. Snow patches in the majority of the watersheds had higher nitrogen and phosphorous concentrations than stream water, and six streams contained snow with higher N:P ratios than the average N:P in the stream water. This suggests that if such patches melt early in the summer, these nutrient and water inputs could occur at the right time and stoichiometry to be crucial for early season algal mat growth.

}, keywords = {LTER-MCM, Antarctica, ephemeral stream, polar desert hydrology, runoff generation, snow patch, snowmelt}, issn = {0885-6087}, doi = {10.1002/hyp.v38.610.1002/hyp.15195}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/hyp.15195}, author = {Wright, Anna T. and Michael N. Gooseff and Bergstrom, Anna J. and Kathleen A. Welch} } @mastersthesis {4588, title = {Hydrologic response to foehn winds in the McMurdo Dry Valleys, Southern Victoria Land, Antarctica}, volume = {M.S.}, year = {2021}, month = {2020}, school = {University of Colorado Boulder}, type = {masters}, address = {Boulder, CO}, abstract = {

In the McMurdo Dry Valleys (MDVs), foehn winds are a principal vector of landscape connectivity that facilitate movement of materials between glaciers, streams, soils, lakes and other parts of the ecosystem. While previous publications show that turbulent, warm and dry foehn winds indirectly relate to an increase in lake level rise via an increase in degree days above freezing (DDAF), the direct quantified impact of foehn winds to streamflow and lake level rise remains unclear. The MDVs are the largest ice-free region of Antarctica, which experience minimal precipitation. Valley bottoms contain permanently ice-covered closed basin lakes filled with meltwater from outlet glaciers via stream channels. In Taylor Valley, several meteorological stations and lake monitoring stations record average measurements of weather conditions and lake conditions on 15 to 20-minute intervals. In this thesis, the meteorological definition of foehn winds is refined and hydrologic response to foehn winds is evaluated. During the austral summer streamflow season (November - February), foehn winds are predicted to increase meltwater generation and closed-basin lake level rise. Past publications have shown that foehn wind events contribute to lake ice sublimation year-round, whereas melt does not typically occur in nonsummer months. Analysis of non-summer lake ice ablation utilizing recent lake stage and ablation data is also explored herein. Although a significant correlation was not found, summer foehn winds appear to promote above average daily lake level rise given sufficient air temperatures. Daily average lake level rise is greater for longer periods (i.e., 4-day average daily rise \> 3-day average daily rise, etc.) indicating that there is at least a 4-day post-foehn impact on lake level rise during the summer. Lake ice ablation in non-summer months is shown to have a significant relationship with increasing foehn wind occurrence and wind-run. Because foehn winds are expected to increase with global warming, these hydrologic relationships aid in predicting the future of the McMurdo Dry Valley ecosystem in a warming world.

}, keywords = {LTER-MCM, Antarctica, foehn, foehn winds, hydrologic, katabatic, McMurdo, wind}, url = {https://www.proquest.com/docview/2488126937}, author = {Beane, Samuel J. and Michael N. Gooseff} } @article {4373, title = {The hydroecology of an ephemeral wetland in the McMurdo Dry Valleys, Antarctica}, journal = {Journal of Geophysical Research: Biogeosciences}, year = {2019}, month = {11/2019}, abstract = {

The McMurdo Dry Valleys (MDV) is a polar desert on the coast of East Antarctica where ephemeral wetlands become hydrologically active during warm and sunny summers when sub-surface flows are generated from melting snowfields. To understand the structure and function of polar wetland ecosystems, we investigated the hydroecology of one such wetland, the Wormherder Creek wetland, during the warm and sunny summer of 2008 \– 2009, when the wetland was hydrologically reactivated. Conservative tracer (LiCl) was injected for a 2-hour period into a stream above the wetland to determine flow path orientations and hydrologic residence times. Tracer results indicated that surface water is rapidly exchanged with wetland groundwater and wetland residence times may exceed two austral summers. Major ion concentrations were uniform in samples from surface water and shallow groundwater throughout the wetland. Microbial mats in the wetland had high autotrophic index values (the ratios of chlorophyll a [Chl-a]/ash-free dry mass [AFDM]), ranging from 9-38 μg Chl-a/mg AFDM, indicative of actively photosynthesizing mat communities. The diatom communities in the mats were relatively uniform compared to those in mats from regularly flowing MDV streams, with four endemic and one widespread diatom taxa of the genus Luticola accounting for an average of 86\% of the community. These results indicate that the hydrologic characteristics of the wetland contribute to uniform geochemical conditions. In turn, uniform geochemical conditions may explain the high autotrophic index values of the microbial mats and relatively low spatial variation of the diatom community.

}, keywords = {LTER-MCM, Antarctica, desert hydrology, diatom biodiversity, hyporheic interactions, wetlands}, doi = {10.1029/2019JG005153}, url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JG005153}, author = {Wlostowski, Adam and Schulte, Nicholas O. and Byron Adams and Ball, Becky and Rhea M.M. Esposito and Michael N. Gooseff and W. Berry Lyons and Uffe N. Nielsen and Ross A. Virginia and Diana H. Wall and Kathleen A. Welch and Diane M. McKnight} } @article {4101, title = {High-resolution elevation mapping of the McMurdo Dry Valleys, Antarctica, and surrounding regions}, journal = {Earth System Science Data}, volume = {9}, year = {2017}, month = {07/2017}, pages = {435 - 443}, abstract = {

We present detailed surface elevation measurements for the McMurdo Dry Valleys, Antarctica derived from aerial lidar surveys flown in the austral summer of 2014\–2015 as part of an effort to understand geomorphic changes over the past decade. Lidar return density varied from 2 to \> 10 returns m\−2\ with an average of about 5 returns m\−2. Vertical and horizontal accuracies are estimated to be 7 and 3 cm, respectively. In addition to our intended targets, other ad hoc regions were also surveyed including the Pegasus flight facility and two regions on Ross Island, McMurdo Station, Scott Base (and surroundings), and the coastal margin between Cape Royds and Cape Evans. These data are included in this report and data release. The combined data are freely available at\ https://doi.org/10.5069/G9D50JX3.

}, keywords = {LTER-MCM}, doi = {10.5194/essd-9-435-2017}, url = {https://www.earth-syst-sci-data.net/9/435/2017/essd-9-435-2017.pdf}, author = {Andrew G Fountain and Fernandez-Diaz, Juan C. and Maciek K. Obryk and Joseph S. Levy and Michael N. Gooseff and David J. Van Horn and Morin, P and Shrestha, Ramesh} } @article {4023, title = {Hydrologic connectivity and implications for ecosystem processes - Lessons from naked watersheds}, journal = {Geomorphology}, volume = {277}, year = {2017}, month = {01/2017}, pages = {63 - 71}, abstract = {

Hydrologic connectivity has received great attention recently as our conceptual models of watersheds and water quality have evolved in the past several decades. However, the structural complexity of most temperate watersheds (i.e. connections among shallow soils, deep aquifers, the atmosphere and streams) and the dynamic seasonal changes that occur within them (i.e., plant senescence which impacts evapotranspiration) create significant challenges to characterizing or quantifying hydrologic connectivity. The McMurdo Dry Valleys, a polar desert in Antarctica, provide a unique opportunity to study hydrologic connectivity because there is no vegetative cover (and therefore no transpiration), and no deep aquifers connected to surface soils or streams. Glacier melt provides stream flow to well-established channels and closed-basin, ice-covered lakes on the valley floor. Streams are also connected to shallow hyporheic zones along their lengths, which are bounded at ~75 cm depth by ice-cemented permafrost. These hydrologic features and connections provide water for and underpin biological communities. Hence, exchange of water among them provides a vector for exchange of energy and dissolved solutes. Connectivity is dynamic on timescales of a day to a flow season (6\–12 weeks), as streamflow varies over these timescales. The timescales over which these connections occur is also dynamic. Exchanges between streams and hyporheic zones, for example, have been estimated to be as short as hours to as long as several weeks. These exchanges have significant implications for the biogeochemistry of these systems and the biotic communities in each feature. Here we evaluate the lessons we can learn about hydrologic connectivity in the MDV watersheds that are simplified in the context of processes occurring and water reservoirs included in the landscape, yet are sensitive to climate controls and contain substantial physical heterogeneity. We specifically explore several metrics that are simple and/or commonly employed in hydrologic analyses and interpret them in the context of connectivity between and among hydrologic features.

}, keywords = {LTER-MCM}, issn = {0169555X}, doi = {10.1016/j.geomorph.2016.04.024}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0169555X16302483}, author = {Michael N. Gooseff and Wlostowski, Adam and Diane M. McKnight and Chris Jaros} } @phdthesis {4161, title = {Hydrologic connectivity in the McMurdo Dry Valleys, Antarctica: Water-mediated mass and energy fluxes in streams and soils}, volume = {Ph.D.}, year = {2017}, school = {University of Colorado Boulder}, type = {doctoral}, address = {Boulder, CO}, abstract = {

Chapter 1 synthesizes 20 years of stream gauge observations (discharge, water temperature, and specific conductance) to assess patterns of hydrologic connectivity between glaciers, streams and lakes. Results reveal hydrologic patterns across daily, annual and inter-annual timescales, which together characterize the hydrologic regime of MDV streams. Also, stream gauge data display a relationship between stream length and hydrologic regime. Longer streams are more intermittent, warmer, and saltier than shorter streams. This work provides physical context for understanding biological differences among MDV streams, while providing a methodological template for quantifying hydrologic connectivity.

Chapter 2 investigates the nature of concentration-discharge relationships for weathering-derived solutes in MDV streams. The relative simplicity of MDV \“watersheds\” permits the use of concentration-discharge relationships to infer hydrologic and chemical mixing dynamics occurring along the river corridor. Long-term stream geochemical data show that weathering derived solutes exhibit chemostatic C-Q relationships. Chemostasis implies that rates of solute production and/or mobilization scale proportionately with stream discharge. A numerical weathering and solute transport model suggests that chemostasis is maintained by a positive relationship between weathering rate and discharge along the stream corridor.

Finally, Chapters 3 and 4 investigate water-mediated energy fluxes within the soil habitat. Nematode communities in MDV are highly sensitive to the thermodynamic regime of active layer soils. Soil moisture and air temperature data were collected across natural wetness gradients adjacent to fluvial features to assess the control of soil moisture on the soil thermal regime. Observations show that wetter soils freeze less frequently and more gradually than drier soils. Also, a numerical soil heat transfer model suggests that increases in soil moisture and air temperature result in warmer average habitat temperature, an extension of the duration of time the soil habitat spends above freezing, and a reduction in the rate and frequency of freezing. The results of this chapter provide a physical context for understanding current and future patterns of ecosystem structure and function in MDV soils.

}, keywords = {LTER-MCM}, url = {https://scholar.colorado.edu/cven_gradetds/77/}, author = {Wlostowski, Adam and Michael N. Gooseff} } @article {3951, title = {Hydrological Controls on Ecosystem Dynamics in Lake Fryxell, Antarctica}, journal = {PLOS ONE}, volume = {11}, year = {2016}, month = {07/2016}, pages = {e0159038}, keywords = {LTER-MCM}, doi = {10.1371/journal.pone.015903810.1371}, url = {http://dx.plos.org/10.1371/journal.pone.0159038}, author = {Herbei, Radu and Rytel, Alexander L. and W. Berry Lyons and Diane M. McKnight and Chris Jaros and Michael N. Gooseff and John C. Priscu}, editor = {Hewitt, Judi} } @mastersthesis {4163, title = {Hydrologic controls of nutrient fluxes in glacial meltwater streams at inter-annual, seasonal, and daily timescales in the McMurdo Dry Valleys, Antarctica}, volume = {M.S.}, year = {2011}, school = {Pennsylvania State University}, type = {masters}, abstract = {

In the McMurdo Dry Valleys of Antarctica, glaciers are hydrologically linked to closed-basin lakes at the valley floor by glacial meltwater streams. Streams flow through porous, well-defined channels with extensive chemically active hyporheic zones. Temporally varying dynamics of meltwater generation and sub-stream thaw depth are thought to control the potential for the hyporheic zone and benthic communities to influence transport of nutrients and dissolved ions downstream. Using the McMurdo LTER database, patterns in stream discharge, electrical conductivity (both with 15-minute sampling intervals), and solute chemistry (weekly sampling intervals) were examined on eight MDV streams from 1990-2008. Discharge and electrical conductivity values were highly variable among streams. Discharge values were highly dependent upon glacial source area, but meteorological and topographical complexities create large variability at all time scales. The longer streams were found to have much higher electrical conductivity values than the shorter streams, suggesting that there are more opportunities for hyporheic weathering reactions along longer stream reaches. Weekly sampled water solutes from each stream\&$\#$39;s entire record were plotted against the discharge recorded at the time when the sample was taken. Silicate concentrations displayed a decreasing logarithmic relationship, while nutrient concentrations had no apparent relationship. This suggests that with the exception to bioreactive solutes, the majority of hyporheic interactions could possibly be characterized by electrical conductivity and discharge. To attain information on in-stream nutrient dynamics and nutrient fluxes, glacial source water at the upper reach of Green Creek and stream outlet water at the lower reach of Green Creek were sampled hourly for two separate diel periods during the 2008-09 austral summer. Both dates were in late January under two distinct flow conditions (~0.5 L/s and ~10 L/s). Under low flow conditions, nutrient cycling was found to be uptake dominated. High flow conditions showed both uptake and regeneration with much higher nutrient loads, but as in the low flow conditions, no apparent temporal trends were found. Nutrient concentrations could not be predicted using the two parameters of discharge and electrical conductivity with in-stream nutrient dynamics likely too complicated at the sub-daily scale.

}, keywords = {LTER-MCM, Antarctica, biogeochemistry, chemical weathering, discharge, electrical conductivity, glacial melt, glaciers, hydrology, hyporheic, MCM LTER, McMurdo Dry Valleys, nutrient fluxes, nutrients, polar desert, solute chemistry, stream chemistry, streamflow, water chemistry}, url = {https://etda.libraries.psu.edu/catalog/11568}, author = {Weaver, Mitchell R. and Michael N. Gooseff} } @article {1135, title = {Hydrological Connectivity of the Landscape of the McMurdo Dry Valleys, Antarctica}, journal = {Geography Compass}, volume = {5}, year = {2011}, month = {09/2011}, pages = {666 - 681}, keywords = {LTER-MCM}, doi = {10.1111/j.1749-8198.2011.00445.x}, url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1749-8198.2011.00445.x}, author = {Michael N. Gooseff and Diane M. McKnight and Peter T. Doran and Andrew G Fountain and W. Berry Lyons} } @article {1186, title = {Hydrologic characteristics of lake- and stream-side riparian wetted margins in the McMurdo Dry Valleys, Antarctica}, journal = {Hydrological Processes}, volume = {23}, year = {2009}, pages = {1255-1267}, keywords = {LTER-MCM}, doi = {LTER}, author = {Northcott, M and Michael N. Gooseff and John E. Barrett and Lydia H. Zeglin and Cristina D. Takacs-Vesbach and Humphrey, J} } @inbook {1214, title = {High-latitude rivers and streams.}, booktitle = {Polar Lakes and Rivers: Limnology of Arctic and Antarctic Aquatic Ecosystems}, year = {2008}, publisher = {Oxford University Press}, organization = {Oxford University Press}, address = {Oxford}, keywords = {LTER-MCM}, doi = {LTER}, author = {Diane M. McKnight and Michael N. Gooseff and Warwick F. Vincent and Peterson, B}, editor = {Warwick F. Vincent and Johanna Laybourn-Parry} }