Identifying the influencing factors of soil nitrous acid emissions using random forest model

Gaseous nitrous acid (HONO) plays an important role in atmospheric chemistry, but there is still controversy regarding its sources. Recent studies have shown that soil can emit significant amounts of HONO. In order to further investigate the impact mechanism of soil HONO emissions and refine the estimation model of soil HONO emissions fluxes, this study employed a random forest model to estimate soil HONO emission fluxes and identified key influencing factors. By measuring in the laboratory and integrating global literature on soil HONO emissions, this study analyzed the characteristics of soil HONO emissions and their relationship with environmental factors. The results indicated that croplands emit significantly more HONO than other land use types. Furthermore, during wet-dry cycles, total soil HONO emissions showed a significant positive correlation with NO2− content and clay content, and also correlated significantly with maximum HONO emissions, total NO emissions, and maximum NO emissions (P