Absorbance

Absorbance measured at a specific wavelength. We measured CDOM absorbance between 250 and 800 nm using a UV-visible Cary 100 (Agilent, Santa Clara, CA), Cary 300 (Agilent, Santa Clara, CA) or LAMBDA 650 (PerkinElmer, Waltham, MA) spectrophotometer, depending on the sample origin. After subtracting the blank spectrum, we applied a null-point adjustment, using the mean value from 750 to 800 nm.

Absorbance unit [A.U.]