Large contributions of soil emissions to the atmospheric nitrogen budget and their impacts on air quality and temperature rise in North China
oleh: T. Sha, S. Yang, Q. Chen, L. Li, X. Ma, Y.-L. Zhang, Y.-L. Zhang, Z. Feng, K. F. Boersma, K. F. Boersma, J. Wang
| Format: | Article |
|---|---|
| Diterbitkan: | Copernicus Publications 2024-07-01 |
Deskripsi
<p>Soil emissions of nitrogen compounds, including NO and HONO, play a significant role in the atmospheric nitrogen budget. However, HONO has been overlooked in previous research on soil reactive nitrogen (Nr) emissions and their impacts on air quality in China. This study estimates soil <span class="inline-formula">NO<sub><i>x</i></sub></span> and soil HONO emissions (SNO<span class="inline-formula"><sub><i>x</i></sub></span> and SHONO) in North China during July 2018 using an updated soil Nr emissions scheme in a chemical transport model, Unified Inputs (initial and boundary conditions) for Weather Research and Forecasting coupled with Chemistry (UI-WRF-Chem). The effects of soil Nr emissions on <span class="inline-formula">O<sub>3</sub></span> pollution, air quality and temperature rise are also studied, with a focus on two key regions, Beijing–Tianjin–Hebei (BTH) and the Fenwei Plain (FWP), known for high soil Nr and anthropogenic emissions. We find that the flux of SNO<span class="inline-formula"><sub><i>x</i></sub></span> is nearly double that of SHONO. The monthly contributions of SNO<span class="inline-formula"><sub><i>x</i></sub></span> and SHONO account, respectively, for 37.3 % and 13.5 % of anthropogenic <span class="inline-formula">NO<sub><i>x</i></sub></span> emissions in BTH and for 29.2 % and 19.2 % in the FWP during July 2018. Soil Nr emissions have a significant impact on surface <span class="inline-formula">O<sub>3</sub></span> and nitrate, exceeding SNO<span class="inline-formula"><sub><i>x</i></sub></span> or SHONO effects alone. On average, soil Nr emissions increase maximum daily 8 h (MDA8) <span class="inline-formula">O<sub>3</sub></span> by 16.9 % and nitrate concentrations by 42.4 % in BTH, and they increase MDA8 <span class="inline-formula">O<sub>3</sub></span> by 17.2 % and nitrate concentrations by 42.7 % in the FWP. Reducing anthropogenic <span class="inline-formula">NO<sub><i>x</i></sub></span> emissions leads to a more substantial suppressive effect of soil Nr emissions on <span class="inline-formula">O<sub>3</sub></span> mitigation, particularly in BTH. Soil Nr emissions, through their role as precursors for secondary inorganic aerosols, can result in a slower increase rate of surface air temperature in future emissions reduction scenarios. This study suggests that mitigating <span class="inline-formula">O<sub>3</sub></span> pollution and addressing climate change in China should consider the role of soil Nr emissions and their regional differences.</p>