Improving the ability of coupled chemistry-climate models to project future changes in polar stratospheric ozone and its influence on surface climate in the polar regions

这项研究的主要目的是减少极地臭氧变化预测到2100年的不确定性及其对极地地区地表气候的影响。实现这一目标的第一步将是应用最近开发的诊断工具来评估最先进的化学-气候耦合模式捕捉导致臭氧消耗的平流层过程的关键敏感性的能力。这些工具由符合化学-气候模型输出的半经验方程组成。第一个诊断追踪氯激活对极地平流层温度和氯负载量的敏感性，从而确定温室气体引起的极地平流层温度变化与臭氧消耗之间的联系。第二个半经验公式跟踪从第一个公式获得的臭氧变化率对氯活化的敏感度。这些方程的拟合系数将与将诊断工具应用于真实世界观测所获得的系数进行比较，从而为化学-气候模型建立性能基准。这些活动将在世界气候研究方案的核心项目SPARC(平流层过程及其在气候中的作用)的国际化学-气候模型验证活动范围内进行。实现拟议目标的第二步将是根据极地臭氧变化对地表气候辐射强迫的贡献，对改进的极地臭氧变化预测进行诊断。

The primary objective of the intended research is to reduce uncertainty in projections of polar ozone changes to 2100 and their influence on surface climate in the polar regions. The first step towards achieving this goal will be to apply recently developed diagnostic tools to assess the ability of state-of-the-art coupled chemistry-climate models to capture key sensitivities characterising the stratospheric processes leading to ozone depletion. These tools consist of semi-empirical equations that are fitted to chemistry-climate model output. The first diagnostic tracks the sensitivity of chlorine activation to polar stratospheric temperatures and chlorine loading and thereby establishes a connection between greenhouse gas induced changes in polar stratospheric temperatures and ozone depletion. The second semi-empirical equation tracks the sensitivity of the rate of change of ozone to chlorine activation obtained from the first equation. The fit coefficients from these equations will be compared with those obtained from application of the diagnostic tools to real world observations thus establishing performance benchmarks for the chemistry-climate models. These activities will take place within the international Chemistry-Climate Model Validation Activity of SPARC (Stratospheric Processes And their Role in Climate), a core project of the World Climate Research Programme. The second step towards achieving the proposal objectives will be diagnosis of the improved projections of polar ozone changes in terms of their contribution to radiative forcing of surface climate in the polar regions.