Chl-a: Chlorophyll-a concentration [μg/L]
LSWT: Lake surface water temperature [degrees K]
TUR: Turbidity [NTU]; indicator of water clarity, quantifying the opacity of the water and acting as an indicator of underwater light availability.
TSI: Trophic State Index [unitless]; an indicator of lake productivity in terms of phytoplankton. Obtained from chlorophyll-a observations, averaged over the observation period, TSI has a value of 0, 10, 20, 30, 40, 50, 0, 70, 80, 90, or 100 corresponding to the classes given in Carlson (1977), where 0-40 are oligotrophic, 40-60 mesotrophic, 60-80 eutrophic, and 80-100 hypereutrophic.