New International Collaborations for Atmospheric Ozone Research

Tropospheric ozone is an important air pollutant, harmful to human health, agricultural crops and vegetation. It is the main precursor to the atmospheric oxidants which initiate the degradation of most reactive gases emitted to the atmosphere, and is an important greenhouse gas in its own right. As a consequence of this central role in atmospheric chemistry and air pollution, the capacity to understand, predict and manage tropospheric ozone levels is a key goal for atmospheric science research. This goal is hard to achieve, as ozone is a secondary pollutant, formed in the atmosphere from the complex oxidation of VOCs in the presence of NOx and sunlight, and a combination of in situ chemical processes, deposition and transport govern ozone levels. Uncertainties in all of these factors affect the accuracy of numerical models used to predict current and future ozone levels, and so hinder development of optimal air quality policies to mitigate ozone exposure. The timescale of ozone chemistry leads to it being a transboundary pollutant, requiring international collaboration for both scientific understanding and the development of effective ozone pollution mitigation policies.

Through ongoing NERC funding, we have developed a novel approach for the direct measurement of local chemical ozone production rates - a capability which avoids limitations inherent in emissions inventories and chemical mechanisms, and which explicitly distinguishes between the chemical and dynamical factors controlling local ozone production.

Within this IOF project, we will develop a new collaboration with researchers from Mines Douai, Lille - the only other group in Europe with direct ozone production rate measurement capability - in support of exchanging expertise, leading to a formal intercomparison of the two instruments, in order to identify any "unknown unknowns" affecting the measurements differently, and permit an independent evaluation of the measurement accuracy and precision.

We will then link with leading researchers in the US to perform a novel proof-of-concept demonstration of the application of multiple ozone production rate measurement instruments from different groups together. Within this pump-priming project, we will apply this approach to understand how ozone production varies in different forest types (different tree populations have different emission profiles for volatile organic compounds, which in turn affect ozone chemistry). We will use two locations at the University of Michigan Biological Station, one which reflects the contemporary (primarily deciduous) aspen woodland of the region, and one in which interventions have accelerated the forest succession towards a larger coniferous population (reflecting the anticipated evolution of forest population in this area). By performing simultaneous parallel ozone production rate measurements in these two locations, with all other factors (e.g. background air composition, meteorology) constant, the change in ozone chemistry anticipated from shifting forest tree population may be directly ascertained.

This concept (combined simultaneous direct ozone production measurements) has scope for application in other scenarios, for example investigating the evolution in ozone chemistry downwind of an emission source (such as a major city), or in a UK context the changing ozone production as polluted European airmasses are advected over the British Isles - events such as the 2003 photochemical smog episode, which are predicted to occur with greater frequency in the future. The final component of this pump-priming project is to initiate a network between researchers with direct ozone production rate measurement capability internationally, in order to facilitate collaborations to apply this concept in the future.

This pump-priming project will demonstrate the viability and potential for international collaboration in performing combined ozone production rate measurements to deliver improved understanding of atmospheric ozone behaviour. It will also deliver new scientific insight into our current understanding of atmospheric ozone formation in evolving forested environments.

Accordingly we identify two key groups of immediate beneficiaries

-Research scientists studying all aspects of atmospheric ozone chemistry, and impacts of ozone upon climate, vegetation and human health.

-The air quality community, and policy makers involved in the development and formulation of air pollution control measures.

We will ensure the impact of the project to these groups is maximised through the development of a network between researchers working with direct ozone production rate measurement capability, as outlined in the main Case for Support. In addition, through links to our current NERC research (Integrated Chemistry of Ozone in the Atmosphere, NE/K012169/1), this IOF Pump-Priming project will contribute to, and benefit from, the following specific activities to maximise impact (all funded through NE/K012169/1).

(1) Direct liaison with the relevant atmospheric science research community, leveraging the PIs ongoing links to a range of relevant projects and groupings such as NCAS, TF HTAP

(2) Direct dissemination of the project results, and new measurement capability, to the Air Quality community, through our links to bodies such as AQEG

(3) Discussion workshop on the topic of "Local Chemical Ozone Production" , and contribution to a forum for the knowledge exchange over capabilities and needs in atmospheric measurement, between the atmospheric science research community, air quality monitoring practitioners, and those at the interface between atmospheric research and air quality policy, supported by the IAQM and learned societies.

Wider Beneficiaries: Scientific Community; General Public
Further application of the new internationally collaborative approach proposed here will lead, both directly and through improved general scientific understanding, to improved ozone control strategies / policies. This will benefit the general public, as tropospheric ozone is a key pollutant, harmful to health, reducing crop yields, damaging materials and contributing to climate change. The outcomes of this work will therefore address two of the key RCUK definitions of impact, namely "increasing the effectiveness of public policy" and "enhancing quality of life and health".