@mastersthesis {3201,
	title = {Elemental Cycling in a Flow-Through Lake in the McMurdo Dry Valleys, Antarctica: Lake Miers},
	volume = {Master Thesis},
	year = {2014},
	month = {06/2014},
	pages = {122},
	school = {Ohio State University},
	type = {masters},
	address = {Columbus},
	abstract = {<p>The ice-free area in Antarctica known as the McMurdo Dry Valleys has been monitored biologically, meteorologically, hydrologically, and geochemically continuously since the onset of the MCM-LTER in 1993. This area contains a functioning ecosystem living in an extremely delicate environment. Only a few degrees of difference in air temperature can effect on the hydrologic system, making it a prime area to study ongoing climate change. The unique hydrology of Lake Miers, i.e. its flowthrough nature, makes it an ideal candidate to study the mass balance of a McMurdo Dry Valley lake because both input and output concentrations can be analyzed. This study seeks to understand the physical and geochemical hydrology of Lake Miers relative to other MCMDV lakes. Samples were collected from the two inflowing streams, the outflowing stream, and the lake itself at 11 depths to analyze a suite of major cations (Li+ , Na+ , K+ , Mg+ , Ca2+), major anions (Cl- , Br- , F- , SO4 2- , ΣCO2), nutrients (NO2 - , NO3 - , NH4 + , PO4 3- , Si), trace elements (Mo, Rb, Sr, Ba, U, V, Cu, As), water isotopes (δD, δ 18O), and dissolved organic carbon (DOC). The lake acts as a sink for all constituents analyzed, but by amounts varying from ~10\% (DOC, NH4 + , and NO2 - ) to PO4 3- at nearly 100\%, indicating this lake may be P-limited. Cl- , a typically conservative element, was only 79\% retained, which could be due to the late season sample collection, hyperheic zone influences, or other factors. The hyperheic zone\&rsquo;s role in lake and stream iii geochemistry was analyzed with a 24-hour sampling event. The positive relationships between stream flow and solute concentrations indicate that the delta in Miers Valley plays a role in controlling stream geochemistry and future work could help to explain this relationship. Lake depth profiles of trace elements U, V, Cu, and As decrease relative to Cl in the deepest part of the lake, while non-reducing trace elements show increases with depth. SO4 2- and dissolved O2 lake depth profiles decrease from 53 μM and 22.3 mg/L to 18 μM and 1.8 mg/L, respectively, at depth, indicating that the lake bottom is under reducing and near anoxic conditions. Lake depth profiles show that, while the \&ldquo;biological pump\&rdquo; may be a factor controlling lake chemistry, it is masked by the stronger signal of diffusion from the lake bottom sediments and requires future work to understand fully. The \&ldquo;age\&rdquo; of Lake Miers was calculated with a diffusion model to be 84 years, which agrees with other estimates of 100-300 years. The diffusion of solutes from the lake bottom and the redox conditions at depth are two major processes controlling the geochemistry of Lake Miers, and future work can help determine their extent and relationship with other processes.</p>},
	keywords = {LTER-MCM},
	url = {https://etd.ohiolink.edu/!etd.send_file?accession=osu1413291502\&disposition=inline},
	author = {Alexandria Corinne Fair and W. Berry Lyons},
	editor = {Anne E. Carey and Yu-Ping Chin}
}
@article {1077,
	title = {Characterization of fulvic acid fractions of dissolved organic matter during ice-out in a hyper-eutrophic, coastal pond in Antarctica},
	journal = {Environmental Research Letters},
	volume = {8},
	year = {2013},
	month = {12/2013},
	pages = {045015},
	abstract = {Dissolved humic material (HDOM) is ubiquitous to all natural waters and its source material influences its chemical structure, reactivity, and bioavailability. While terrestrially derived HDOM reference materials distributed by the International Humic Substances Society (IHSS) have been readily available to engineering and scientific communities, a microbially derived reference HDOM was not, despite the well-characterized differences in the chemistry and reactivity of HDOM derived from terrestrial versus microbial sources. To address this gap, we collected a microbial reference fulvic acid from Pony Lake (PLFA) for distribution through the IHSS. Pony Lake is a saline coastal pond on Ross Island, Antarctica, where the landscape is devoid of terrestrial plants. Sample collection occurred over a 17-day period in the summer season at Pony Lake. During this time, the dissolved organic carbon (DOC) concentrations increased nearly two-fold, and the fulvic acid fraction (collected using the XAD-8 method) accounted for 14.6\% of the DOC. During the re-concentration and desalting procedures we isolated two other chemically distinct fulvic acid fractions: (1) PLFA-2, which was high in carbohydrates and (2) PLFA-CER, which was high in nitrogen. The chemical characteristics (elemental analysis, optical characterization with UV{\textendash}vis and fluorescence spectroscopy, and 13C NMR spectroscopy) of the three fulvic acid fractions helped to explain their behavior during isolation.},
	keywords = {LTER-MCM},
	doi = {10.1088/1748-9326/8/4/045015},
	author = {Kaelin M. Cawley and Diane M. McKnight and Penney L. Miller and Rose M. Cory and Fimmen, Ryan L and Guerard, Jennifer and Markus Dieser and Chris Jaros and Yu-Ping Chin and Christine M. Foreman}
}
@article {1088,
	title = {Microbial growth under humic-free conditions in a supraglacial stream system on the Cotton Glacier, Antarctica},
	journal = {Environmental Research Letters},
	volume = {8},
	year = {2013},
	month = {09/2013},
	pages = {035022},
	abstract = {During the austral summers of 2004 and 2009, we sampled a supraglacial stream on the Cotton Glacier, Antarctica. The stream dissolved organic matter (DOM) was low (44{\textendash}48 μM C) and lacked detectable humic fluorescence signatures. Analysis of the excitation emissions matrices (EEMs) indicated that amino-acid fluorophores dominated, consistent with DOM of microbial origin, with little humic-like fluorescence. In most aquatic ecosystems, humic DOM attenuates harmful UV radiation and its absence may represent an additional stressor influencing the microbial community. Nonetheless, the stream contained an active microbial assemblage with bacterial cell abundances from 2.94 {\texttimes} 104 to 4.97 {\texttimes} 105 cells ml-1, and bacterial production ranging from 58.8 to 293.2 ng C l-1 d-1. Chlorophyll-a concentrations ranged from 0.3 to 0.53 μg l-1 indicating that algal phototrophs were the probable source of the DOM. Microbial isolates produced a rainbow of pigment colors, suggesting adaptation to stress, and were similar to those from other cryogenic systems (Proteobacteria and Bacteroidetes lineages). Supraglacial streams provide an example of contemporary microbial processes on the glacier surface and a natural laboratory for studying microbial adaptation to the absence of humics.},
	keywords = {LTER-MCM},
	doi = {10.1088/1748-9326/8/3/035022},
	url = {http://iopscience.iop.org/1748-9326/8/3/035022},
	author = {Christine M. Foreman and Rose M. Cory and Morris, Cindy E and Michael D. SanClements and Smith, Heidi J and John T. Lisle and Penney L. Miller and Yu-Ping Chin and Diane M. McKnight}
}
@article {1081,
	title = {Physicochemical and biological dynamics in a coastal Antarctic lake as it transitions from frozen to open water},
	journal = {Antarctic Science},
	volume = {25},
	year = {2013},
	month = {12/2013},
	pages = {663{\textendash}675},
	keywords = {LTER-MCM},
	author = {Markus Dieser and Christine M. Foreman and Chris Jaros and John T. Lisle and Mark C. Greenwood and Johanna Laybourn-Parry and Penney L. Miller and Yu-Ping Chin and Diane M. McKnight}
}
@article {1138,
	title = {When a habitat freezes solid: microorganisms over-winter within the ice column of a coastal Antarctic lake},
	journal = {FEMS Microbiology Ecology},
	volume = {76},
	year = {2011},
	month = {06/2011},
	pages = {401 - 412},
	keywords = {LTER-MCM},
	doi = {10.1111/j.1574-6941.2011.01061.x},
	url = {http://onlinelibrary.wiley.com/doi/10.1111/j.1574-6941.2011.01061.x/full},
	author = {Christine M. Foreman and Markus Dieser and Mark Greenwood and Rose M. Cory and Johanna Laybourn-Parry and John T. Lisle and Chris Jaros and Penney L. Miller and Yu-Ping Chin and Diane M. McKnight}
}
