Abstract：
Ground-level ozone adversely affects human health and ecosystems. The effectiveness of control programs depends on which precursor(s) are controlled, by how much, and where and when emission reductions occur. We use the adjoint of the Community Multiscale Air Quality model to investigate odd oxygen (Ox ≡ O3 + NO2) sensitivities in California\'s San Joaquin Valley (SJV) to precursor emissions from local and upwind sources. Sensitivities are mapped and disaggregated by hour and day. Taken together, impacts of precursor emissions in the San Francisco Bay area and Sacramento Valley are similar in magnitude to impacts of local SJV emissions. Same-day emission sensitivities are mostly attributable to local sources, with the most influential anthropogenic emissions of VOCs (volatile organic compounds) and NOx (nitrogen oxides) occurring in the morning (9-11 am) and early afternoon hours (1-3 pm), respectively. For the northernmost SJV receptor, the influence from Sacramento Valley emissions peaks 5-6 h later than Bay area emissions; this difference diminishes for SJV receptors located further downwind. Results show a shift toward more NOx-sensitive conditions in the afternoon with all but the southernmost receptor shifting from VOC- to NOx-sensitive conditions. We also evaluate opportunities to control pollution through shifts in precursor emission location and timing.
摘要：
地面臭氧对人类健康和生态系统产生不利影响。控制程序的有效性取决于控制的前体，多少,以及减排发生的地点和时间。我们使用社区多尺度空气质量模型的伴随研究了加利福尼亚州圣华金河谷（SJV）对本地和上风向源前体排放的奇数氧（Ox=O3NO2）敏感性。敏感度按小时和天绘制和分类。一起来看,旧金山湾区和萨克拉门托谷地前体排放的影响与当地SJV排放的影响程度相似。当天的排放敏感性主要归因于当地来源，最具影响力的人为排放VOCs(挥发性有机化合物)和NOx(氮氧化物)发生在上午(上午9-11点)和下午早些时候(下午1-3点)，分别。对于最北端的SJV受体，萨克拉曼多山谷排放的影响比湾区排放晚5-6小时；对于位于下风更远的SJV受体，这种差异会减小。结果显示下午向更多的NOx敏感条件转变,除了最南端的受体之外,所有的都从VOC-向NOx敏感条件转变。我们还通过前体排放位置和时间的变化来评估控制污染的机会。
