Introduction
Colored (or chromophoric) dissolved organic matter (CDOM) is the part of organic matter that absorbs light in the blue and UV part of the electromagnetic spectrum, staining water a “tea-like” yellow-brown color. CDOM plays major roles in freshwater ecosystem processes, determining physical and chemical conditions and water quality in freshwaters. Dissolved organic matter (DOM) occurs in all natural waters and CDOM is the most abundant DOM fraction in in forested watersheds with wetlands.
Click here for background information on CDOM
Our studies on CDOM have encompassed a range of topics beyond its measurement by remote sensing. For information on these research areas, click on the following links:
- Results from recent field studies on CDOM behavior in lakes
- Efforts to develop smartphone app to measure CDOM
- How CDOM affects drinking water treatment processes
New CDOM videos available
Our group recently produced two videos on CDOM, one describing its basic properties and why it is important in lake ecology and human uses of lakes, and the other describing various methods, including remote sensing and smartphones, for measuring it.
To see them, click on the icons below:
Colored Dissolved Organic Matter (CDOM)
CDOM distribution in Minnesota lakes
We began measuring CDOM in Minnesota lakes by satellite imagery in 2014 (Olmanson et al. 2016) and expanded to statewide coverage in 2015 using a combination of the Landsat 8 and Sentinel-2 satellites. Statewide CDOM distribution based on averages for 2015 and 2016 imagery is shown below, and the bar graphs show distributions of CDOM in lakes by major aquatic ecoregion. For more information and results for your lake of interest, click the LakeBrowser button.
CDOM distribution in lakes across the NLF and NCHF ecoregions
We also have examined CDOM distributions across the Northern Lakes and Forests (NLF) and North Central Hardwood Forests (NCHF) ecoregions, which span the three Upper Great Lakes states of Minnesota, Wisconsin and Michigan. This work was supported by the National Science Foundation and involved analysis of landscape conditions in lake watersheds that control CDOM levels in lakes. It is apparent from the inset at upper right that CDOM distribution is highly variable, even in small regions. The histograms below show that the NLF ecoregion has a much higher range and median CDOM levels than the NCHF ecoregion.
