Aquatic Organic Matter in the Arctic
Remote SEnsing of DOM
Colored dissolved organic matter (CDOM) can be measured from satellite imagery in many aquatic ecosystems, and used to quantify changes in aquatic carbon cycling. My dissertation research built remote sensing models for six large Arctic rivers to estimate CDOM (Griffin et al., 2018), then applied those models to historical imagery from 1985 - 2017 (Griffin, 2016). Time series analyses showed changes to discharge-normalized CDOM in the Ob' and Yenisey rivers, likely associated with increases in permafrost thaw.
River export of OM
I have been lucky to be involved with the Arctic Great Rivers Observatory, which provided the data used for my remote sensing methods. Through Arctic-GRO, I have contributed to work on fluxes of particulate organic matter (POM), addressing the variability in export driven by both seasonal and annual hydrology (McClelland et al., 2016). Organic matter in Arctic rivers generally increases in age by the end of the ice-free season. Radiocarbon dating of lignins demonstrated that such ancient pools of carbon are far more prevalent in the Kolyma River than the Mackenzie River (Feng et al., 2017).