Motivation

Radiative forcing of N₂O is 265 times higher than CO₂ at a 100-year time horizon according to the 5^th IPCC report. However, global investigations on N₂O fluxes have been much limited compared to CO₂-related studies, and there remain high uncertainties on the key drivers and their impacts on nitrification, denitrification, and above-belowground nitrogen exchange processes. A few biosphere models have the capability in simulating N₂O emissions at global scale, but large divergence exist among their estimations due to inconsistent input data sets, experiment designs and model algorithms. We are poorly informed of how model structures and parameters affect N₂O estimation in response to multi-factor global changes in both natural and managed ecosystems. The NMIP – Global and regional N₂O model Inter-comparison Project by using consistent input data and simulation protocol is designated to estimate the global terrestrial N₂O fluxes and uncertainties associated with model structure and parameters. The global and regional N₂O estimates derived from NMIP will be a critical component of the Global N₂O Budget Report jointly led by GCP (Global Carbon Project) and INI (International Nitrogen Initiative).

Objectives

1. Synthesize the existing estimates of N₂O fluxes from ground-based observations, inventories, and statistical/empirical approaches;
2. Develop consistent historical (1860-2016) gridded data sets of environment drivers including climate, atmospheric composition, land conversion and land management practices at global scale;
3. Quantify the magnitude, spatial and temporal patterns of global N₂O fluxes during 1860-2016, and understand the impacts of environmental drivers on N₂O dynamics, through data-model integration and model-model inter-comparison;

Coordinator and Contact Information:
Dr. Hanqin Tian
Dixon Professor and Director
International Center for Climate and Global Change Research
School of Forestry and Wildlife Sciences
Auburn University, 602 Duncan Drive, Auburn, AL 36849, USA.
 334-844-1059
 tianhan@auburn.edu