The Global Nitrogen Model Inter-comparison Project Protocol
NMIP (The global Nitrogen/N2O Model Inter-comparison Project) is an international partnership of model-model and data-model intercomparison under the umbrella of the Global Carbon Project (GCP) and International Nitrogen Initiative (INI).
Goals
- The Primary Goal of the NMIP-2 is to focus on the quantification and attribution of N2O emissions, which includes the objectives as follows: 1) to provide more reliable estimates of regional (and/or national) and global soil N2O emissions with an update to the year 2019/2020, covering a period of 1850-2020, 2) to attribute soil N2O emissions to anthropogenic nitrogen addition and other factors, and 3) to provide an estimate of indirect N2O emission from N leaching to inland water systems (River, Lakes and Reservoir)
- The Secondary Goal of NMIP-2 is to better understand the terrestrial nitrogen cycle and its interactions with other factors, which includes the objective as follows: 1) to provide an assessment of the global terrestrial nitrogen budget, 2) to understand and quantify N-Nexus: how do anthropogenic N inputs affect carbon (C sink), water (N loading), air (NH3 and NOx) and crop yield
Simulations
| Historical | Climate | CO2 | Land cover | Irrigation | Ndep | Nfer | ManureN |
|---|---|---|---|---|---|---|---|
| SH0 | 1901-1920 | 1850 | 1850 | 1850 | 1850 | 1850 | 1850 |
| SH1 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 |
| SH2 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850 |
| SH3 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850 | 1850-2020 |
| SH4 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850 | 1850-2020 | 1850-2020 |
| SH5 | 1850-2020 | 1850-2020 | 1850-2020 | 1850 | 1850-2020 | 1850-2020 | 1850-2020 |
| SH6 | 1850-2020 | 1850-2020 | 1850 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 |
| SH7 | 1850-2020 | 1850 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 |
| SH8 | 1901-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 | 1850-2020 |
| SH9 | 1901-2020 | 1850 | 1850 | 1850 | 1850 | 1850-2020 | 1850-2020 |
| SH10 | 1850-2020 | 1850 | 1850 | 1850 | 1850 | 1850 | 1850 |
Required output variables
Nitrogen-related variables
| Long name | Unit | Output variable name | Frequency | Level |
|---|---|---|---|---|
| Nitrogen fluxes | ||||
| N2O emission | kg m-2 s-1 | fN2O | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| N2O emission from inland waters (Indirect emission) | kg m-2 s-1 | fN2Oiw | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| N leaching | kg m-2 s-1 | fNleach | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Biological N fixation | kg m-2 s-1 | fBNF | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Nitrification rate | kg m-2 s-1 | fNnitri | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Denitrification rate | kg m-2 s-1 | fNdenitri | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Net N mineralization | kg m-2 s-1 | fNnetmin | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Plant N uptake | kg m-2 s-1 | fNup | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| NH3 volatilization | kg m-2 s-1 | fNH3vol | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Harvest N | kg m-2 s-1 | fNHarvest | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Grazed N | kg m-2 s-1 | fNGrazing | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| N2 emission | kg m-2 s-1 | fN2 | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| NOx emissions | kg m-2 s-1 | fNOx | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| N export to ocean | kg m-2 s-1 | fNland_ocean | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Nitrogen pools | ||||
| Nitrogen in soil | kg m-2 | nSoil | Annual (1850-2020) | Grid-level |
| Nitrogen in vegetation | kg m-2 | nVeg | Annual (1850-2020) | Grid-level |
| Nitrogen in litter | kg m-2 | nLitter | Annual (1850-2020) | Grid-level |
| Nitrogen in products | kg m-2 | nProduct | Annual (1850-2020) | Grid-level |
Carbon-related variables
| Long name | Unit | Output variable name | Frequency | Level |
|---|---|---|---|---|
| Carbon fluxes | ||||
| Gross primary production | kg m-2 s-1 | gpp | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Autotrophic respiration | kg m-2 s-1 | ra | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Net primary production | kg m-2 s-1 | npp | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Heterotrophic respiration | kg m-2 s-1 | rh | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Net Biome Production | kg m-2 s-1 | nep | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Harvest C | kg m-2 s-1 | cHarvest | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Grazed C | kg m-2 s-1 | cGrazing | Monthly (1980-2020) Annual (1850-2020) | Grid- and biome-levels |
| Carbon pools | ||||
| Carbon in soil | kg m-2 | cSoil | Annual (1850-2020) | Grid-level |
| Carbon in vegetation | kg m-2 | cVeg | Annual (1850-2020) | Grid-level |
| Carbon in litter | kg m-2 | cLitter | Annual (1850-2020) | Grid-level |
| Carbon in products | kg m-2 | cProduct | Annual (1850-2020) | Grid-level |
References
- Tian, H., Yang, J., Lu, C., Xu, R., Canadell, J.G., Jackson, R.B., Arneth, A., Chang, J., Chen, G., Ciais, P. and Gerber, S., 2018. The global N 2 O model intercomparison project. Bulletin of the American Meteorological Society, 99(6), pp.1231-1251. https://doi.org/10.1175/BAMS-D-17-0212.1