Prof. Dr. Timothy Shaw
Projekte & Publikationen
The global carbon cycle is the ultimate mediator of greenhouse gas induced global warming. Excess atmospheric carbon dioxide (CO2) from fossil fuel burning is the primary cause of warming, but it makes up only a small fraction of CO2 exchange between the earth and atmosphere. The biological portion of the carbon cycle accounts for a much larger fraction of the CO2 exchange so small changes in the processes that mediate CO2 uptake and release are critical to predicting future climate change.
The exchange of biogenic carbon (as dissolved organic matter DOM) between land and the oceans is a critical portion of the cycle. Chemical reactions that occur at the land/sea interface determine whether DOM is sequestered (buried) or remineralized (returned to the atmosphere as CO2). Changes in the amount of DOM that is remineralized to CO2 can alter the reservoir of atmospheric CO2.
This proposal will investigate processes that mediate the remineralization of DOM at the land sea interface. DOM undergoes a range of chemical reactions at the dynamic land sea interface. The beachfront environment is one where the rapid mixing of terrestrial and marine waters creates a zone of high DOM transformation. One reason for this is the production of a set of “super” oxidants called Reactive Oxygen Species (ROS) that have the potential to “burn up” DOM to transform it to CO2 at this interface. This work is critical to determining the net fate of DOM passing through this critical zone of reactivity.