South Asian Nitrogen Hub Regional Marine Biogeochemistry Model hindcast runs under three nitrogen production scenarios (2004-2020)

This dataset contains outputs of three simulations from an ocean-biogeochemistry (NEMO v.4.0.4 - ERSEM) model over the South East Asia region. Atmospheric forcing is provided by ERA5, with lateral ocean boundaries from the CMEMS global forecast. Biogeochemical tracers are initialised and forced by a combination of world ocean atlas, GloDAP, and OC-CCI data. The output is provided as daily and monthly files on a {t,u,v,w}-grid. Additional monthly output used in the construction of a nitrogen budget is also provided. Three different simulations were run with varying river input and nitrogen deposition: 1) under current legislation conditions (at the time of publication), which include projected trends of activity and change in environmental factors to include the impact of recent legislation (for example the mandatory use of Neem Coated Urea); 2) under maximum technically feasible reduction in overall nitrogen production conditions, including the projected trends of activity, the impact of current legislation (e.g. neem coated urea), along with further reductions such as the amount of permissible nitrogen pollution from fertilizer use and reduced emissions from housing; 3) under maximum technically feasible reduction in overall nitrogen production plus a change in human diet conditions, including the projected trends of activity, the impact of current legislation, along with further reductions such as the amount of permissible nitrogen pollution from fertilizer use and reduced emissions from housing, and the additional assumption of an overall change in human diet towards foods that produce less nitrogen during their production. The simulations are performed as hindcasts but are used to assess future behaviour under a given scenario. The model configuration is named SAsia. The outputs were generated under the South Asian Nitrogen Hub (SANH; NE/S009019/1) project.