VARIABLE	LABEL	REFERENCE
d18O_H2O	Stable oxygen isotope ratios of water.  The data are in parts per thousand (o/oo) and referenced to Vienna Standard Mean Ocean Water (VSMOW). The water was obtained as a subsample of the water chemistry sample.	
dD_H2O	Stable hydrogen isotope ratios of water.  The data are in parts per thousand (o/oo) and referenced to Vienna Standard Mean Ocean Water (VSMOW). The water was obtained as a subsample of the water chemistry sample.	
E_I	"Evaporation-inflow ratio, the proportion of inflowing water to a lake that is lost through evaporation, estimated from water isotopes. E_I values with 0 indicate all water flows through the lake without significant evaporation, and E_I values of 1 indicate all water entering the lake leaves through evaporation.  Values larger than 1 indicate desiccating lakes."	"Brooks, J. R., J. J. Gibson, S. J. Birks, M. H. Weber, K. Rodecap, and J. L. Stoddard. 2014. Stable Isotope estimates of lake water evaporation:inflow and residence time for lakes across the United States as a tool for national lake water quality assessments. Limnology and Oceanography 59:2150-2165."
RT	Lake water residence time (units = years) estimated from water stable isotopes.	"Brooks, J. R., J. J. Gibson, S. J. Birks, M. H. Weber, K. Rodecap, and J. L. Stoddard. 2014. Stable Isotope estimates of lake water evaporation:inflow and residence time for lakes across the United States as a tool for national lake water quality assessments. Limnology and Oceanography 59:2150-2165."
AGGR_ECO3_2015	"NARS 3-level reporting region (2015), based on aggregating AGGR_ECO9_2015 reporting regions"	
AGGR_ECO9_2015	"NARS 9-level reporting region (2015), based on aggregated Omernik Level III ecoregions"	
STATE	State lake is assigned to for sampling in NLA 2012	
DATE_COL	Date of sample collection	
SITE_ID	Identification code for site	
VISIT_NO	Sequential number of visit to site	
PUBLICATION_DATE	Date the dataset was published to the NARS site	
UID	Unique identifier for the site/visit	
ECO_BIO	"Five aggregated ecoregions as used in NLA (CPL, EHIGH, PLAINS, UMW, WMTNS)"	
LAB	Laboratory