EGU23-8295, updated on 25 Feb 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Estimating the global lateral transfer of nitrogen through river network using a land surface model

Minna Ma1, Haicheng Zhang2, Pierre Regnier1, Ronny Lauerwald3, and Philippe Ciais4
Minna Ma et al.
  • 1Department Geoscience, Environment & Society-BGEOSYS, Université libre de Bruxelles, 1050 Bruxelles, Belgium
  • 2School of Geography and Planning, Sun Yat-sen University, Guangzhou, Guangdong, 510006, China
  • 3Université Paris-Saclay, INRAE, AgroParisTech, UMR ECOSYS, 78850, Thiverval-Grignon, France
  • 4Laboratoire des Sciences du Climat et de l’Environnement, IPSL-LSCE CEA/CNRS/UVSQ, Orme des Merisiers, 91191, Gif sur Yvette, France

Lateral nitrogen (N) transport from land to the ocean through rivers is an important component of global N cycling. In this study, we present the implementation of fluvial transport of nitrogen into ORCHIDEE-CNP (Organising Carbon and Hydrology in Dynamic Ecosystems-CNP), which explicitly simulates N biogeochemistry in terrestrial ecosystems coupled with carbon, water and energy transfers. This new model branch called ORCHIDEE-Nlateral, simulates the lateral transport of water, dissolved inorganic N (DIN), dissolved organic N (DON) and particulate organic N (PON) from land to the ocean through river networks, the decomposition of DON and PON, and the denitrification of DIN in transit. ORCHIDEE-Nlateral was parameterized and evaluated based on global observations of water discharge (Global Runoff and Dara Centre, GRDC) and N concentration in the global river network (Global Water Quality Archive, GRQA). The model reproduces well the observed riverine discharges of water and total nitrogen (TN), and N exports from the land to the ocean.  Globally, the TN flowing into rivers, denitrification of DIN and TN export to the ocean all increased from the year 1901 to 2015. The TN export to the ocean increased from 32 Tg N yr-1 to 37 Tg N yr-1 during 1901–2015, which is in good agreement with the corresponding global fluxes calculated from the well-established Global NEWS 2 model. In this study, we further re-assess the spatial and temporal distribution of global riverine N flows and stocks. Overall, our model approach represents a useful tool for simulating large-scale lateral N transfer and for predicting the future feedbacks between lateral N transfers and climate.

How to cite: Ma, M., Zhang, H., Regnier, P., Lauerwald, R., and Ciais, P.: Estimating the global lateral transfer of nitrogen through river network using a land surface model, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-8295,, 2023.