Exceedances of NO₂ hourly limit value (200 μg·m⁻³) imply the need to implement short term action plans to avoid adverse effects on human health in urban areas. The Madrid City Council applied the stage 3 of the NO₂ protocol during a high-pollution episode under stable meteorological conditions on December 2016 for the first time. This included road traffic access restrictions to the city centre (50% of conventional private vehicles based on plate numbers). In this contribution we analyse different meteorological and air quality observations, including non-standard parameters (such as number of ultrafine particles and remote sensing techniques MAXDOAS) for a better understanding of the effectivity of short-term emission abatement measures under real conditions and to identify options to improve the NO₂ protocol in the future. According to our results, the inversion base height computed from vertical temperature soundings is a meaningful index to anticipate very unfavourable conditions and trigger the actions included in the protocol. The analysis of the concentration levels of the main pollutants from the Madrid air quality monitoring network indicate that only stage 3 of the protocol had a significant effect on NO₂ maximum concentrations. The restrictions applied may have prevented NO₂ concentrations to further increase in the city centre (up to 15%) although pollution levels in the city outskirts, outside the area directly affected by the traffic restrictions, remained unchanged or may have been slightly increased. Nonetheless, further studies are needed to estimate more precisely the effect of the measures taken and to assess potential trade-offs. Our results suggest that emissions play an important role also under very strong stability conditions although drastic measures are needed to achieve a significant impact. This highlights the importance of an appropriate timing for short-term actions and the need of permanent abatement measures related to air quality plans and policies.

超过NO ₂每小时限值（200μg·m ^-3）意味着需要执行短期行动计划，以避免对城市地区的人类健康产生不利影响。马德里市议会采用了NO ₂的第3阶段在2016年12月首次在稳定的气象条件下的高污染事件中实施该协议。其中包括通往市中心的道路交通限制（按车牌号，占传统私家车的50％）。在这项贡献中，我们分析了不同的气象和空气质量观测值，包括非标准参数（例如超细颗粒的数量和遥感技术MAXDOAS），以便更好地了解实际条件下短期减排措施的有效性，并确定改善NO _2的选项未来的协议。根据我们的结果，根据垂直温度测算得出的反演基准高度是有意义的指标，可以预测非常不利的条件并触发协议中包含的操作。对来自马德里空气质量监测网络的主要污染物的浓度水平的分析表明，只有议定书的第3阶段对NO _2的最大浓度有显着影响。所施加的限制可能阻止了NO ₂尽管在受交通限制直接影响的地区以外，城市郊区的污染水平保持不变，或者可能略有增加，但市中心的污染物浓度仍将进一步提高（最高15％）。尽管如此，仍需要进一步研究以更准确地估计所采取措施的效果并评估潜在的权衡。我们的结果表明，尽管需要采取严厉措施来取得重大影响，但在非常强的稳定性条件下，排放也起着重要作用。这突出了为短期行动采取适当时机的重要性，以及与空气质量计划和政策有关的永久性减排措施的必要性。