Annual evapotranspiration (ET)

Annual precipitation and discharge

Boiling/freezing points of water vs. other substances

Density and viscosity of water

ET and daily discharge

Global distribution of water

Latent heat of vaporization/melting

Temperature-density of water

Solar energy reaching earth

Light/latitude/season

Light transmission through ice

Light transmission isopleths

Light transmission in water

Light penetration-snow/ice

Light absorption by water

Light absorption by colored H2O

Vertical light penetration

Secchi depth by season

Secchi depth and plants

Secchi depth and color

Electromagnetic spectrum

Photosynthetic absorbance (PAR)