Multiple 50-member ensemble simulations with the Community Earth System Model version 2 are performed to estimate the coupled climate responses to the 2019–2020 Australian wildfires and COVID-19 pandemic policies. The climate response to the pandemic is found to be weak generally, with global-mean net top-of-atmosphere radiative anomalies of +0.23 ± 0.14 W m⁻² driving a gradual global warming of 0.05 ± 0.04 K by the end of 2022. While regional anomalies are detectable in aerosol burdens and clear-sky radiation, few significant anomalies exist in other fields due to internal variability. In contrast, the simulated response to Australian wildfires is a strong and rapid cooling, peaking globally at −0.95 ± 0.15 W m⁻² in late 2019 with a global cooling of 0.06 ± 0.04 K by mid-2020. Transport of fire aerosols throughout the Southern Hemisphere increases albedo and drives a strong interhemispheric radiative contrast, with simulated responses that are consistent generally with those to a Southern Hemisphere volcanic eruption.

中文翻译：

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对近期澳大利亚野火和 CESM2 中估计的 COVID-19 排放异常的耦合气候响应

使用社区地球系统模型第 2 版进行了多次 50 人集合模拟，以估计对 2019-2020 年澳大利亚野火和 COVID-19 大流行政策的耦合气候响应。发现对大流行的气候响应普遍较弱，全球平均净大气顶部辐射异常为 +0.23 ± 0.14 W m ^-2，到 2022 年底导致全球逐渐变暖 0.05 ± 0.04 K。虽然在气溶胶负荷和晴空辐射中可以检测到区域异常，但由于内部变化，其他领域几乎没有显着异常。相比之下，对澳大利亚野火的模拟反应是强烈而快速的降温，全球峰值为− 0.95 ± 0.15 W m ⁻²2019 年末，到 2020 年年中全球降温 0.06 ± 0.04 K。整个南半球的火气溶胶传输增加了反照率并驱动了强烈的半球间辐射对比，模拟响应与南半球火山喷发的响应大致一致。