Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States.
Laboratory for Aviation and the Environment, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Environ Sci Technol. 2023 May 2;57(17):6955-6964. doi: 10.1021/acs.est.2c07253. Epub 2023 Apr 20.
High-resolution simulations are essential to resolve fine-scale air pollution patterns due to localized emissions, nonlinear chemical feedbacks, and complex meteorology. However, high-resolution global simulations of air quality remain rare, especially of the Global South. Here, we exploit recent developments to the GEOS-Chem model in its high-performance implementation to conduct 1-year simulations in 2015 at cubed-sphere C360 (∼25 km) and C48 (∼200 km) resolutions. We investigate the resolution dependence of population exposure and sectoral contributions to surface fine particulate matter (PM) and nitrogen dioxide (NO), focusing on understudied regions. Our results indicate pronounced spatial heterogeneity at high resolution (C360) with large global population-weighted normalized root-mean-square difference (PW-NRMSD) across resolutions for primary (62-126%) and secondary (26-35%) PM species. Developing regions are more sensitive to spatial resolution resulting from sparse pollution hotspots, with PW-NRMSD for PM in the Global South (33%), 1.3 times higher than globally. The PW-NRMSD for PM for discrete southern cities (49%) is substantially higher than for more clustered northern cities (28%). We find that the relative order of sectoral contributions to population exposure depends on simulation resolution, with implications for location-specific air pollution control strategies.
高分辨率模拟对于解析由于局地排放、非线性化学反馈和复杂气象条件导致的细尺度空气污染模式至关重要。然而，空气质量的高分辨率全球模拟仍然很少，特别是在全球南方地区。在这里，我们利用了最新的发展，在高性能实现的 GEOS-Chem 模型中进行了 2015 年的一年模拟，分辨率分别为立方球 C360（约 25 公里）和 C48（约 200 公里）。我们研究了人口暴露和各部门对地表细颗粒物（PM）和二氧化氮（NO）的贡献对分辨率的依赖性，重点关注研究不足的地区。我们的结果表明，在高分辨率（C360）下存在明显的空间异质性，各分辨率之间的全球人口加权归一化均方根差（PW-NRMSD）对一次（62-126%）和二次（26-35%）PM 物种都较大。发展中地区对空间分辨率更为敏感，这是由于污染热点稀疏所致，全球南方地区（33%）的 PM 加权 NRMSD 比全球水平高 1.3 倍。离散的南方城市（49%）的 PM 加权 NRMSD 明显高于更集中的北方城市（28%）。我们发现，各部门对人口暴露的相对贡献顺序取决于模拟分辨率，这对特定地点的空气污染控制策略有影响。
