Detailed water sampling protocols and chemical analyses are found in the Arctic LTER Land-Water group protocol book accessible from the Land-Water mainpage on the Arctic LTER web page or at http://www-personal.umich.edu/~gwk and clicking on the "Lab Protocol Manual" link toward the bottom of the page. Specific methodologies are described in the protocol book listed above, and a general description is provided below.

General analyses:
Water temperature, pH, conductivity, and dissolved gases are measured in the field on whole water (not filtered) from soils, streams, ponds, and lakes. Water for other analyses is filtered in the field and kept cold and dark or preserved until analysis. Dissolved inorganic nutrients (ammonium, NH4 and phosphate, PO4) were analyzed by wet chemistry methods at Toolik Field Station usually within 24 hours of sampling. Dissolved gases, carbon dioxide (CO2) and methane (CH4) were determined using a syringe equilibration method and analyzed at Toolik Field Station on a gas chromatograph. Dissolved organic carbon (DOC), total dissolved nitrogen (TDN), total dissolved phosphorus (TDP), particulate carbon, nitrogen and phosphorus, and dissolved ions were brought back to the University of Michigan for analysis. DOC and TDN are analyzed by high-temperature combustion on a Shimadzu instrument (TOC-V or equivalent), or TDN is analyzed by persulfate digestion. Particulate Carbon and Nitrogen are analyzed on a Perkin Elmer CHN 2400 (or equivalent). TDP and nitrate (NO3) are analyzed on an OI Alpkem autoanalyzer, anions on a Dionex ion chromatograph, and cations on an inductively coupled plasma optical emission spectrometer (ICP-OES Perkin Elmer Optima 4300 or 8000). Alkalinity samples were analyzed potentiometrically on a Radiometer autotitrator.

For all analyses, sample values that were less than zero were assigned a value of zero. See specific protocols for limits of detection. Missing values (not sampled or analyzed) are represented by a period " . " in the dataset.