Fog geoenginneering to abate ozone pollution

A new idea to cut back on local ozone (O₃) pollution: spray water mist into the atmosphere from the ground to enhance air moisture, similar to creating fog in nature. This suggestion comes from Prof. Shaocai Yu of Zhejiang University in China, and California Institute of Technology in the US. In an article published in Springer’s journal Environmental Chemistry Letters (https://rdcu.be/7mPF, https://link.springer.com/article/10.1007/s10311-018-0809-5, Yu, S. Environ Chem Lett (2018). https://doi.org/10.1007/s10311-018-0809-5),  Prof. Yu suggests this course of action as a novel approach to help curb the severe ozone pollution at ground level that is experienced in many urban and industrial regions for both developing and developed countries around the world.  Prof. Yu proposes spraying water mist into the atmosphere to simulate natural types of fog that are able to most effectively enhance air moisture to suppress ozone formation and destroys the existing ozone photo-chemically during the sunlight day time. This geoengineering scheme could help to reduce the ozone pollution in the atmosphere efficiently to a safer level of 70 ppb. For instance, the mean O3 concentrations decrease from 70.0 to 21.2 ppbv when relative humidity increases from below 40% to more than 80%, in Hangzhou city at midday times (11:00–16:00) without precipitation, during the “ozone season” from May to October of 2017. And it could be done in a short time, depending how the water mist is sprayed. This geoengineering technique is very natural, technologically feasible, efficient and low cost. All the necessary technologies and materials required to make it work are already available.  Evaporative cooling by fog geoengineering can also be used to fight urban heat island, even for global warming. Research and experiments are currently underway to design a suitable water-delivery system to successfully implement this fog geoengineering option. Prof. Yu plans on putting the experiment to the test in Zhejiang University campus and then Hangzhou, the city where Zhejiang University is located.

Reference: Yu, S. Fog geoengineering to abate local ozone pollution at ground level by enhancing air moisture. Environ Chem Lett (2018). https://doi.org/10.1007/s10311-018-0809-5