Chemical Characterization of Natural Dissolved Organic Matter

The global reservoir of dissolved organic carbon (DOC) occupies a unique and enigmatic place within the planet's carbon cycle. Its size (670 Gt C) is comparable to the atmospheric inventory of carbon dioxide (760 Gt C) as well as to that of the planet's living terrestrial biomass (~800 Gt C), yet the reasons underlying its thermodynamically unstable persistence, from centuries to millennia, in the oxygenated water columns of Earth's lakes and oceans remain unclear. This elusiveness principally derives from DOM's vast chemical complexity and heterogeneity, which rivals only that of kerogen, the most complex chemical mixture known to this planet which similarly resists comprehensive structural and molecular characterization at every turn. My research in the Aluwihare lab uses high resolution analytical techniques, combined with elemental, isotopic, and other organic geochemical measurements to better elucidate this pool of organic carbon, its origins, modes of persistence, and fate in the environment.