PARAMETER	UNITS	DEFINITION	METHODS	NOTES	DATA ANALYSIS
LOG NUMBER	Dimensionless	A unique internal sample identifier
CRUISE CODE	Dimensionless	Name of cruise when sample was taken
SAMPLE DATE	MM/DD/YY	Date sample was taken from lake
STATION	Dimensionless	Station occupied when sample was taken	In normal conditions, samples are taken within 1/2 mi of the lat/long corresponding to the station location.
DEPTH	m	Depth sample was taken.	Depth indicated on CTD when Niskin bottle was fired. Depth sensor is 0.9 m below midpoint of vertical Niskin bottle; depths given here are not corrected for that difference.
FRACTION	m * 10-6	Pore size of filter used to fractionate before sample collection.	Water taken from Niskin, transferred into carboy, then fractionated as indicated. "W" or "whole" are unfractionated whole water. From "80" to "20" water has been passed through Nitex of that mesh size. "10" may be Nitex or 47 mm polycarbonate filter. Smaller than 10, water is first prefiltered through 10 um, then "2" is a polycarbonate filter of varying diameter. "0.7" is 47mm Whatman GF/F. "0.2" is 47 mm polycarbonate filter.
STORAGE	Dimensionless	Method of sample preservation	Frozen = stored at approx. -4 C with liquid samples in HDPE bottles; fridge = stored at approx 4 C.
VOL FILT	Ml	Volume of sample filtered.		This volume used to calculate particulate concentration in the lake.
REP	Dimensionless	Integer value, replicate number.		Normally replicates are from the same Niskin bottle.
SAMPLE_TYPE	Dimensionless	Type of sample (sed/core/water)	"Water" samples are taken from the water column."Sediment" means a mud sample, taken from the ponar or a subsample from the mulitcorer and analyzed.  "Core" samples refer to water samples from the headspace above sediment cores taken with the multicorer.
DIC	mg/L	Dissolved inorganic carbon.	Using Shimadzu VCSH.	Contains carbonates and CO2.
DOC	mg/L	Dissolved organic carbon	Using Shimadzu VCSH. Post acification to pH of 2 and sparging with purified air.	Organic carbon present in a sample in a nonvolatile form.
TN	mg/L	Total nitrogen	Using Shimadzu VCSH with TNM-1 attachment.
TDN	mg/L	Total dissolved nitrogen.	Using Shimadzu VCSH with TNM-1 attachment.	High detection for nitrates, nitrites and ammonia and the majority of other organic N compounds. Low detection for hydrazines, pyrazolones and azide.
POC	ug/L	Particulate Organic Carbon	Sample collected on ashed GF/F filter. Frozen, dried at 60C. Run on Perkin Elmer 2400 CHN analyzer.
PON	ug/L	Particulate Organic Nitrogen	Sample collected on ashed GF/F filter. Frozen, dried at 60C. Run on Perkin Elmer 2400 CHN analyzer.
Probe pH	Dimensionless	Hydrogen ion activity
SRSi	mg/L	Soluble reactive silica	Metol-sulphate/molybdate reaction.
Chl-a	ug/L	Chlorophyll A	Sample filtered onto 25 mm 0.2 um cellulose nitrate filter and frozen. Extracted with 90% Acetone in the refrigerator for 20-24 h (no grinding of filer). Then measured on a Turner 10-AU using narrow band width filters per Welschmeyer xxxx. Once every 4 y, Turner Design liquid standard is used for recalibration. Solid standard used in between.
PP	uM	Particulate phosphorus	Sample filtered onto 25 mm acid-rinsed (~10mL 1% HCl, followed by 50 mL nanopure, rinsed on filter tower) precombusted GF/F filter. Frozen. Dried at 60 C. Analyzed using persulfate then ammonium molybdate reaction.
NH4	uM	Ammoniuum	GF/F filtered sample is frozen. Thawed samples are added to an OPA working reagent per Taylor et al. 2007, using a combination of Holmes et 1. 1999 Methods A and B. Standard addition series done on all samples. Background fluorescence measured after adding working reagent and reading immediately.
NO3	uM	Nitrate	Unfiltered sample is frozen. Thawed sample is run using Cd-reduction protocol on a Lachat flow injection analyzer.