Eos, Transactions American Geophysical Union

Photochemical reactions a sink for dissolved organic carbon



Dissolved organic matter is transported from inland sources through rivers to seas, where it provides a major source of carbon and nitrogen in aquatic ecosystems. Solar radiation can break down dissolved organic matter into a form that is more readily used by bacteria. Photochemical reactions can also transform dissolved organic carbon into forms of dissolved inorganic carbon, including carbon dioxide, and convert dissolved organic nitrogen into ammonium, which encourages bacterial and algal growth. Quantifying these photoreactions could help scientists better understand the role of photochemistry and dissolved organic matter in aquatic ecosystems