Statistical modeling of global soil NO x emissions

On the basis of field measurements of NO x emissions from soils, we developed a statistical model to describe the influences of soil organic carbon (SOC) content, soil pH, land‐cover type, climate, and nitrogen input on NO x emission. While also considering the effects of soil temperature, soil moisture change‐induced pulse emission, and vegetation fire, we simulated NO x emissions from global soils at resolutions of 0.5° and 6 hours. Canopy reduction was included in both data processing and flux simulation. NO x emissions were positively correlated with SOC content and negatively correlated with soil pH. Soils in dry or temperate regions had higher NO x emission potentials than soils in cold or tropical regions. Needleleaf forest and agricultural soils had high NO x emissions. The annual NO x emission from global soils was calculated to be 7.43 Tg N, decreasing to 4.97 Tg N after canopy reduction. Global averages of nitrogen fertilizer–induced emission ratios were 1.16% above soil and 0.70% above canopy. Soil moisture change–induced pulse emission contributed about 4% to global annual NO x emission, and the effect of vegetation fire on soil NO x emission was negligible.