Dissolved organic matter (DOM) is a complex mixture of organic compounds found in all
natural waters. Its composition affects its reactivity towards numerous processes. Its
composition is a function of both its source (e.g., allochthonous or autochthonous) as well
as the extent of environmental processing it has undergone (e.g., chemical or biological
degradation). Ultraviolet-visible (UV-vis) spectroscopy is an analytical technique commonly
used to assess the composition of dissolved organic matter in water samples. Here, we
present spectra from Lake Mendota samples collected from June - November in 2017 at the
surface of Lake Mendota as well as at specific depths within the water column. All samples
were collected near the NTL-LTER research buoy. Absorbance values are listed for wavelengths
200 - 800 nm for each sample.<br/>