PDF(Pubmed)
Abstract：
As cities strive for ambitious increases in tree canopy cover and reductions in anthropogenic volatile organic compound (AVOC) emissions, accurate assessments of the impacts of biogenic VOCs (BVOCs) on air quality become more important. In this study, we aim to quantify the impact of future urban greening on ozone production. BVOC emissions in dense urban areas are often coarsely represented in regional models. We set up a high-resolution (30 m) MEGAN (The Model of Emissions of Gases and Aerosols from Nature version 3.2) to estimate summertime biogenic isoprene emissions in the New York City metro area (NYC-MEGAN). Coupling an observation-constrained box model with NYC-MEGAN isoprene emissions successfully reproduced the observed isoprene concentrations in the city core. We then estimated future isoprene emissions from likely urban greening scenarios and evaluated the potential impact on future ozone production. NYC-MEGAN predicts up to twice as much isoprene emissions in NYC as the coarse-resolution (1.33 km) Biogenic Emission Inventory System version 3.61 (BEIS) on hot summer days. We find that BVOCs drive ozone production on hot summer days, even in the city core, despite large AVOC emissions. If high isoprene emitting species (e.g., oak trees) are planted, future isoprene emissions could increase by 1.4-2.2 times in the city core, which would result in 8-19 ppbv increases in peak ozone on ozone exceedance days with current NOx concentrations. We recommend planting non- or low-isoprene emitting trees in cities with high NOx concentrations to avoid an increase in the frequency and severity of future ozone exceedance events.
摘要：
随着城市努力实现树冠覆盖率的大幅增加和人为挥发性有机化合物（AVOC）排放的减少，准确评估生物VOCs（BVOCs）对空气质量的影响变得越来越重要。在这项研究中,我们旨在量化未来城市绿化对臭氧产生的影响。密集城市地区的BVOC排放通常在区域模型中得到粗略表示。我们建立了高分辨率（30m）MEGAN（《自然》3.2版的气体和气溶胶排放模型），以估算纽约市都会区（NYC-MEGAN）的夏季生物异戊二烯排放。将受观测约束的箱模型与NYC-MEGAN异戊二烯排放耦合成功地再现了城市核心中观测到的异戊二烯浓度。然后，我们从可能的城市绿化情景中估算了未来的异戊二烯排放量，并评估了对未来臭氧生产的潜在影响。NYC-MEGAN预测，在炎热的夏季，纽约市的异戊二烯排放量是粗分辨率（1.33km）生物排放清单系统3.61版（BEIS）的两倍。我们发现BVOCs在炎热的夏季驱动臭氧产生，即使在市中心，尽管AVOC排放量很大。如果高异戊二烯排放物种(例如，橡树)种植，未来城市核心地区的异戊二烯排放量可能增加1.4-2.2倍，在当前的NOx浓度下，这将导致臭氧超标日的峰值臭氧增加8-19ppbv。我们建议在氮氧化物浓度较高的城市种植非异戊二烯或低异戊二烯排放的树木，以避免未来臭氧超标事件的频率和严重程度增加。
