In this study, we show using a state-of-the-art Earth system model, UKESM1, that emissions and climate scenario depending, there could be large changes in surface ozone by the end of the twenty-first century, with unprecedentedly large increases over South and East Asia. We also show that statistical modelling of the trends in future ozone works well in reproducing the model output between 1900 and 2050. However, beyond 2050, and especially under large climate change scenarios, the statistical model results are in poorer agreement with the fully interactive Earth system model output. This suggests that additional processes occurring in the Earth system model such as changes in the production of ozone at higher temperatures or changes in the influx of ozone from the stratosphere, which are not captured by the statistical model, have a first order impact on the evolution of surface ozone over the twenty-first century. We show in a series of idealized box model simulations, with two different chemical schemes, that changes in temperature lead to diverging responses between the schemes. This points at the chemical mechanisms as being a source of uncertainty in the response of ozone to changes in temperature, and so climate, in the future. This underscores the need for more work to be performed to better understand the response of ozone to changes in temperature and constrain how well this relationship is simulated in models. This article is part of a discussion meeting issue ‘Air quality, past present and future’.

中文翻译：

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二十一世纪地表臭氧的变化：对地表温度和化学机制变化的敏感性


在这项研究中，我们使用最先进的地球系统模型 UKESM1 表明，根据排放量和气候情景，到二十一世纪末，地表臭氧可能会发生巨大变化，出现前所未有的大幅增加覆盖南亚和东亚。我们还表明，未来臭氧趋势的统计模型可以很好地再现 1900 年至 2050 年之间的模型输出。然而，2050 年之后，特别是在大规模气候变化情景下，统计模型结果与完全互动的地球的一致性较差系统模型输出。这表明地球系统模型中发生的其他过程，例如统计模型未捕获的较高温度下臭氧产生的变化或来自平流层的臭氧流入的变化，对演化具有一级影响二十一世纪的地表臭氧。我们在一系列理想化的盒模型模拟中展示了两种不同的化学方案，温度的变化导致方案之间的响应不同。这表明化学机制是臭氧对未来温度和气候变化的响应的不确定性来源。这强调需要开展更多工作，以更好地了解臭氧对温度变化的响应，并限制模型中模拟这种关系的程度。本文是“空气质量，过去、现在和未来”讨论会议的一部分。