Field measurements performed in the Keihin coastal industrial area during summer 2019 were used to characterize the air quality and ozone production potential. The total hydroxyl radical (OH) reactivity was found to be moderate, peaking with a 2-h average of 29.0 s⁻¹, corresponding to an OH lifetime of ∼34 ms. The average hourly total OH reactivity was 11.4 ± 5.2 s⁻¹ (average ± standard deviation), and the measured OH sinks (from over 90 trace species) accounted for 92.3% of the total OH reactivity. Compared with a previous series of campaigns in urban/suburban Japan, this field work investigated an area often overlooked for atmospheric observations and found the smallest missing OH reactivity (on average, 0.88 s⁻¹). The near-zero missing OH reactivity indicated that photochemical procedures were less important to the Yokohama air quality study (AQUAS–Yokohama) than the ubiquitous substantial secondary products in other areas. This study also demonstrated that oceanic air masses may quickly flush coastal industrial areas and that a limited activity of photochemistry due to elevated NO_x effectively terminates OH radical recycling. A comparison with other campaigns in Japan exhibited a positive correlation with oxidants (ozone and formaldehyde), indicating secondary products have a critical role in explaining missing OH reactivity. The ozone production potential was corresponding to a volatile organic compound (VOC)-limited regime, while the missing OH reactivity led to an ∼8% increase in ozone formation. Finally, a positive correlation was found between the ozone production rate and the reactivity ratio between VOCs and NO_x, in both the current study and various other field campaigns in urban areas.

2019 年夏季在京滨沿海工业区进行的现场测量用于表征空气质量和臭氧产生潜力。发现总羟基自由基 (OH) 反应性适中，在 2 小时平均值为 29.0 s ^{-1 时}达到峰值，对应于约 34 ms 的 OH 寿命。平均每小时总 OH 反应性为 11.4 ± 5.2 s ^-1（平均值 ± 标准偏差），并且测量的 OH 汇（来自 90 多种痕量物质）占总 OH 反应性的 92.3%。与之前在日本城市/郊区开展的一系列活动相比，这项实地工作调查了一个在大气观测中经常被忽视的区域，并发现了最小的缺失 OH 反应性（平均为 0.88 s ^-1）。几乎为零的缺失 OH 反应性表明光化学程序对横滨空气质量研究（AQUAS-Yokohama）的重要性不如其他地区无处不在的大量次级产品。这项研究还表明，海洋气团可能会迅速冲洗沿海工业区，并且由于 NO _x升高导致光化学活动有限有效地终止 OH 自由基循环。与日本其他活动的比较表明，与氧化剂（臭氧和甲醛）呈正相关，表明次级产品在解释缺少 OH 反应性方面起着关键作用。臭氧产生潜力对应于挥发性有机化合物 (VOC) 限制的制度，而缺少 OH 反应性导致臭氧形成增加约 8%。最后，在当前的研究和城市地区的各种其他实地活动中，臭氧产生率与 VOC 和 NO _x之间的反应性比之间存在正相关关系。