Investigation of solar induced climate variability in chemistry-climate model simulations

化学气候模型模拟中太阳引起的气候变化的研究

• 批准号: 396706928
• 负责人: Dr. Markus Kunze
• 金额: --
• 依托单位: Institut für Meteorologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/396706928?language=en
• 关键词: Investigation; solar; induced; climate; variability

Solar induced climate variability is an important part of natural climate variability, detectable in atmospheric chemical and dynamical quantities. The physical processes driving this atmospheric solar signal involve variability in the spectral solar irradiances (SSI), the total solar irradiance (TSI) and also energetic particles precipitating (EPP) at high geomagnetic latitudes into the thermosphere and mesosphere. While the magnitude of the solar signal is large in the upper part of the atmosphere, where a direct impact of SSI variations on ozone chemistry and temperature is observed, the direct impact of TSI variations at the Earth´s surface is rather small. Due to dy-namical processes, which transfer the solar signal downward, an indirect amplification of the solar signal occurs in the troposphere. However, there still exist large uncertainties in quantifying the solar signal and in attributing physical processes to detected solar signals at the surface.The SolVarCCM project aims at further improving our understanding of solar induced climate variability by exploring the most recent model simulations. The Chemistry Climate Model Initia-tive (CCMI) provides an excellent database for the analysis of the solar signal in atmospheric chemistry and dynamics extending from the troposphere to the upper mesosphere. The first part of SolVarCCM addresses a method intercomparison to identify the most appropriate approach to detect the solar signal dependent on the location and quantity. This is of particular importance as the lower stratospheric decadal signal can still not unambiguously be attributed to solar variability. The optimized methods will then be applied to validate the solar signal in CCMI simulations of the recent five decades against observations. This objective of SolVarCCM will contribute directly to the international WCRP/SPARC-SOLARIS-HEPPA initiative. As the CCM-database has some limitations concerning solar forcing alternatives, SolVarCCM will also run a CCM coupled to an interactive ocean to address the influence of the alternative CMIP6-SSI/TSI-dataset and EPP on the solar signal under two different future prediction scenarios. These datasets together with the CCMI-database will allow for the analysis of the solar signal in a number of model subsets to identify processes responsible for the transfer of the solar signal from the middle atmosphere to the troposphere. The still uncertain role of specific solar forcings (EPP and SSI) or the role of model configuration (model top and ocean coupling), on the magnitude of the solar induced cli-mate variability at the surface will be estimated with more confidence than was possible in previ-ous studies. Another new issue to be investigated in SolVarCCM is the role of solar induced cli-mate variability in a changing climate.

太阳引起的气候变率是自然气候变率的一个重要组成部分，可以通过大气化学和动力学量来检测。驱动这种大气太阳信号的物理过程涉及光谱太阳辐照度（SSI），总太阳辐照度（TSI）和高能粒子沉淀（EPP）在高地磁纬度进入热层和中间层的变化。虽然太阳信号的幅度在大气上部很大，在那里观察到SSI变化对臭氧化学和温度的直接影响，但TSI变化对地球表面的直接影响相当小。由于动力学过程将太阳信号向下传递，在对流层中发生太阳信号的间接放大。然而，仍然存在着很大的不确定性，在量化的太阳信号，并归因于物理过程中检测到的太阳信号在地面上SolVarCCM项目的目的是进一步提高我们的理解，通过探索最新的模式模拟太阳引起的气候变率。化学气候模式倡议（CCMI）为分析从对流层到中上层的大气化学和动力学中的太阳信号提供了一个极好的数据库。SolVarCCM的第一部分解决了方法相互比较，以确定最合适的方法来检测太阳信号的位置和数量。这一点特别重要，因为平流层下部的十年信号仍然不能明确地归因于太阳的变化。然后，将应用优化的方法来验证太阳信号在CCMI模拟的观测最近五十年。SolVarCCM的这一目标将直接促进国际WCRP/SPARC-SOLARIS-HEPPA倡议。由于CCM数据库在太阳强迫替代方案方面存在一些局限性，SolVarCCM还将运行一个耦合到交互式海洋的CCM，以解决替代CMIP 6-SSI/TSI数据集和EPP在两种不同的未来预测情景下对太阳信号的影响。这些数据集与CCMI数据库一起，将允许在一些模型子集中分析太阳信号，以确定太阳信号从中层大气层转移到对流层的过程。具体的太阳强迫（EPP和SSI）或模式配置（模式顶部和海洋耦合）对地表太阳诱发气候变率大小的作用仍然不确定，将比以前的研究更有信心地估计。SolVarCCM研究的另一个新问题是太阳引起的气候变率在气候变化中的作用。