For water sampling protocols see 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 protocol link at the bottom of the page. Specific methodologies are described in the protocol book listed above and a general description is provided below.
General analyses: In general water samples from soils, streams, and lakes are filtered in the field and kept cold and dark or preserved until analysis. Dissolved inorganic nutrients (NH4 and PO4) were analyzed by wet chemistry techniques at Toolik Field Station usually within 24 hours of sampling. Prior to 1999, the phenate method was used to analyze the ammonium content. In the years 1999-2001, a comparison study of the OPA method and the phenate method were performed. Starting in 2001, OPA was used to analyze ammonium content. Gas samples were analyzed at Toolik Field Station. DIC samples were acidified in the field and analyzed on a gas chromatograph at Toolik Field Station. DOC, TDN, TDP, particulate C, N, and P, and dissolved ions were brought back to the University of Michigan for analysis. DOC is analyzed on a Shimadzu TOC-5000. Particulate Carbon and Nitrogen on a Perkin Elmer CHN 2400, TDN is analyzed on a Shimadzu TOC-5000 or using a persulfate digestion. TDP and NO3 are analyzed on an OI Alpkem autoanalyzer, ions on a Dionex ion chromatograph, and cations on an inductively coupled plasma optical emission spectrometer (ICP-OESPerkin Elmer Optima 4300 or 8000). Alkalinity samples were run on a Radiometer autotitrator either at Toolik Field Station or at the University of Michigan.
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.

The following data sets were combined into this data set:

Data Set ID File name Tittle
10090 2000_ArcticLTER_Lakes_nuts.csv Nutrient and chemical data for various lakes near Toolik Research Station, Arctic LTER, Summer 2000.
10089 2001_ArcticLTER_Lakes_nuts.csv Nutrient and chemical data for various lakes near Toolik Research Station, Arctic LTER, Summer 2001.
10091 2002_ArcticLTER_Lakes_nuts.csv Nutrient and chemical data for various lakes near Toolik Research Station, Arctic LTER, Summer 2002.
10092 2003_ArcticLTER_Lakes_nuts.csv Nutrient and chemical data for various lakes near Toolik Research Station, Arctic LTER, Summer 2003.
10081 2004_ArcticLTER_Lakes_nuts.csv Nutrient and chemical data for various lakes near Toolik Research Station, Arctic LTER, Summer 2004.
10080 2005_ArcticLTER_Lakes_nuts.csv Nutrient and chemical data for various lakes near Toolik Research Station, Arctic LTER, Summer 2005.
10079 2006_ArcticLTER_Lakes_nuts.csv Nutrient and chemical data for various lakes near Toolik Research Station, Arctic LTER, Summer 2006.
10078 2007_ArcticLTER_Lakes_nuts.csv Nutrient and chemical data for various lakes near Toolik Research Station, Arctic LTER, Summer 2007.
10077 2008_ArcticLTER_Lakes_nuts.csv Nutrient and chemical data for various lakes near Toolik Research Station, Arctic LTER, Summer 2008.
10082 2009_ArcticLTER_Lakes_nuts.csv Nutrient and chemical data for various lakes near Toolik Research Station, Arctic LTER, Summer 2009.