Lagrangian Modeling of Denitrification and Nitrous Oxide Production in Soils

During the fellowship, the experienced researcher Christopher V.

Henri and his supervisors Anker Lajer Højberg and Jens Christian Refsgaard of the Geological Survey of Denmark and Greenland (GEUS) will lead an effort improving the prediction of nitrate levels and of the production of nitrous oxide in soils by developing advanced and accurate modeling techniques.

The widespread use of agrochemicals has led to the contamination of many surface and groundwater bodies around the world. Nitrate is a highly problematic contaminant due to its adverse effect on human health and on ecosystems. Understanding the fate of nitrate in the subsurface is, however complex.

Indeed, the pollutant undergoes in many cases a sequential biochemically induced degradation, which will reduce levels but also produce nitrous oxide, a potent greenhouse gas. Today, numerical models are essential in the management of such groundwater contamination.

Yet, virtually all available numerical solutions for reactive transport in soils use Eulerian methods that present serious numerical issues, which significantly reduce their applicability.

The proposed project will represent a breakthrough in our representation of reactive transport in unsaturated soils by developing a stable and reliable Lagrangian method able to simulate reactive systems as the Nitrate biodegradation.

The method will also allow to identify key processes triggering reactions in soils, which is primordial to improve our management of groundwater contaminations and to better understand the implication that the subsurface production of nitrous oxide can potentially have on climate.

The project will also allow the high-potential applicant to secure a position in Europe and the world-class host institution to maintain excellence through a series transfer of knowledge, training and communication strategy.