Abstract. The radiation belts are regions in the near-Earth space where solar wind electrons are captured by the Earth's magnetic field. A portion of these electrons is continuously lost into the atmosphere where they cause ionization and chemical changes. Driven by the solar activity, the electron forcing leads to ozone variability in the polar stratosphere and mesosphere. Understanding the possible dynamical connections to regional climate is an ongoing research activity which supports the assessment of greenhouse-gas-driven climate change by a better definition of the solar-driven variability. In the context of the Coupled Model Intercomparison Project Phase 6 (CMIP6), energetic electron and proton precipitation is included in the solar-forcing recommendation for the first time. For the radiation belt electrons, the CMIP6 forcing is from a daily zonal-mean proxy model. This zonal-mean model ignores the well-known dependency of precipitation on magnetic local time (MLT), i.e. its diurnal variability. Here we use the Whole Atmosphere Community Climate Model with its lower-ionospheric-chemistry extension (WACCM-D) to study effects of the MLT dependency of electron forcing on the polar-ozone response. We analyse simulations applying MLT-dependent and MLT-independent forcings and contrast the resulting ozone responses in monthly-mean data as well as in monthly means at individual local times. We consider two cases: (1) the year 2003 and (2) an extreme, continuous forcing. Our results indicate that the ozone responses to the MLT-dependent and the MLT-independent forcings are very similar, and the differences found are small compared to those caused by the overall uncertainties related to the representation of electron forcing in climate simulations. We conclude that the use of daily zonal-mean electron forcing will provide an accurate ozone response in long-term climate simulations.

中文翻译：

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辐射带电子降水的磁局部时间依赖性：对极地中层大气臭氧的影响

摘要。辐射带是近地空间中太阳风电子被地球磁场捕获的区域。这些电子的一部分不断丢失到大气中，导致电离和化学变化。在太阳活动的驱动下，电子强迫导致极地平流层和中间层的臭氧变化。了解与区域气候可能的动态联系是一项正在进行的研究活动，它支持通过更好地定义太阳能驱动的可变性来评估温室气体驱动的气候变化。在耦合模型比对项目第 6 阶段 (CMIP6) 的背景下，高能电子和质子沉淀首次包含在太阳强迫建议中。对于辐射带电子，CMIP6 强迫来自每日区域平均代理模型。这种带平均模型忽略了众所周知的降水对磁本地时间 (MLT) 的依赖性，即其昼夜变化。在这里，我们使用整个大气社区气候模型及其低电离层化学扩展 (WACCM-D) 来研究电子强迫的 MLT 依赖性对极地臭氧响应的影响。我们分析了应用与 MLT 相关和与 MLT 无关的强迫的模拟，并对比了月平均数据以及个别当地时间的月平均值中产生的臭氧响应。我们考虑两种情况：（1）2003 年和（2）极端的、持续的强迫。我们的结果表明臭氧对 MLT 依赖和 MLT 独立强迫的响应非常相似，与气候模拟中与电子强迫表示相关的总体不确定性引起的差异相比，发现的差异很小。我们得出的结论是，使用每日纬向平均电子强迫将在长期气候模拟中提供准确的臭氧响应。