An important part of the McMurdo Long Term Ecological Research (LTER) is evaluating carbon and nitrogen budgets in perennial ice-covered lakes. This dataset addresses this core area of research and quantifies the particulate organic carbon (POC) and nitrogen (PON) found at specific depths in lakes across the McMurdo Dry Valleys of Antarctica.
Lake water samples were collected at specific depths with a five-liter Niskin bottle during normal LTER limnological sampling. Sub-samples were decanted into three 1 L Nalgene bottles (two light and one amber), two 500 mL amber Nalgene bottles, three 150 mL borosilicate glass bottles, two 20 mL scintillation vials, and one 30 mL serum vial. A 500 mL sample from the one liter amber Nalgene bottle was decanted and filtered through a combusted Whatman 25 mm GF/F filter (475 °C for 4 hours). The filter was placed onto an aluminum weighing pan and air dried. Once the filters were dry, the pans were stacked together and frozen for later analysis.
Filters were acidified with HCL fumes, and analyzed using an Elemental Analyzer (currently a CE Elantech Flash EA 1112 Elemental Analyzer). Total particulate organic carbon (POC) and particulate organic nitrogen (PON) was obtained by comparison with an acetanilide standard curve.
Prior to the 0304 season, analysis was done on a 10 mm diameter sub-sample punch of the GF/F filter; from 0304 to present, the entire GF/F filter was analyzed. See the maintenance section for further details regarding data from 2003-04 thru the 2019-20 field seasons.
Instrument detection limits for POC and PON are 10 μg punch-1 and 5 μg punch-1 respectively.
Funding for this work has been provided by several grants from the US National Science Foundation for Long Term Ecological Research, most recently under award #OPP-1637708.