Past and future evolution of the 3D Brewer-Dobson circulation

3D Brewer-Dobson 环流的过去和未来演变

• 批准号: 240559849
• 负责人: Dr. Axel Gabriel
• 金额: --
• 依托单位: Abteilung Modellierung atmosphärischer Prozesse
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/240559849?language=en
• 关键词: Past; future; evolution; 3D; Brewer

The Brewer-Dobson circulation (BDC) denotes the time-mean mass circulation of the middle atmosphere (10-100km). The BDC is driven by planetary waves, synoptic-scale waves and gravity waves, and transports ozone (O3), water vapour (H2O) and other trace gas constituents from the tropics to mid- and polar latitudes. The evolution of the zonal mean (2D) BDC in a changing climate and its interaction with the stratospheric ozone layer is an important issue of current research. However, the long-term changes of the 2D BDC and the wave driving strongly differ between the used models and the observations. Examinations based on a formulation of the three-dimensional (3D) BDC might lead to a more detailed picture and an improved understanding of the role of the BDC in a changing climate, but they are very sparse.The aim of the project is to investigate the past and future changes of the 3D BDC and the local wave driving based on the consortia simulations with the Earth-System Model MPI-ESM for the time period 1960-2005 and the climate projections up to the year 2100 (CMIP5). For validation and aspects which cannot be achieved by the CMIP5 simulations alone, the 3D BDC will also be analysed based on simulations with the high-altitude general circulation and chemistry model HAMMONIA (1957-2006), reanalysis (ERA-Interim 1979-2012, MERRA, 1979-2012) and recent satellite data (Aura/MLS 2004-2012). An algorithm will be developed to derive a new data set of daily-mean wind fields from the Aura/MLS data, which will provide a suitable tool for validating the 3D BDC particularly at altitudes where local wind measurements are very sparse (ca. 30-80km). The impact of the 3D BDC on the local long-term changes of O3, H2O, temperature and vorticity in the middle atmosphere, particularly on the ultra-long stationary waves, will be analysed based on linear solutions of the budget equations. The processes controlling the coupling the middle atmospheric 3D BDC, the tropospheric wave activity and wind-driven ocean currents will be examined based on additional model sensitivity simulations with the MPI-ESM including prescribed modulations of surface temperatures, tropospheric and stratospheric eddy fluxes, and middle atmospheric absorber distributions derived from observations. It is also planned to examine the impact of the 3D BDC on the local long-term changes of stratospheric O3 and middle atmospheric H2O based on the chemistry-climate model (CCM) simulations performed and provided by the SPARC (Stratospheric Processes and their Role in Climate) CCM-Validation project.

布鲁尔-多布森环流（BDC）表示中层大气（10-100km）的时间平均质量环流。BDC由行星波、天气尺度波和重力波驱动，并将臭氧（O3）、水蒸气（H2O）和其他微量气体成分从热带输送到中纬度和极纬度。气候变化中纬向平均（2D）边界层的演变及其与平流层臭氧层的相互作用是当前研究的一个重要问题。然而，所使用的模式与观测值之间的二维BDC和波驱动的长期变化存在较大差异。基于三维（3D） BDC公式的检查可能会导致更详细的图像，并提高对BDC在气候变化中的作用的理解，但它们非常稀少。该项目的目的是基于地球系统模式MPI-ESM在1960-2005年期间的联合模拟和2100年的气候预估（CMIP5），研究三维BDC和局地波驱动的过去和未来变化。为了验证CMIP5单独模拟无法实现的验证和方面，还将基于HAMMONIA（1957-2006）、再分析（ERA-Interim 1979-2012， MERRA, 1979-2012）和最近的卫星数据（Aura/MLS 2004-2012）的模拟，对3D BDC进行分析。将开发一种算法，从Aura/MLS数据中导出新的日平均风场数据集，这将为验证3D BDC提供合适的工具，特别是在当地风测量非常稀疏的高度（约30-80公里）。基于预算方程的线性解，分析了三维BDC对局地中层大气O3、H2O、温度和涡度的长期变化，特别是对超长驻波的影响。通过MPI-ESM附加的模式灵敏度模拟，包括地表温度、对流层和平流层涡旋通量的规定调制以及观测所得的中层大气吸收剂分布，研究了控制中层大气三维BDC、对流层波活动和风驱动洋流耦合的过程。基于SPARC (stratospheric Processes and their Role in Climate) CCM- validation项目提供的化学-气候模式（CCM）模拟，研究三维BDC对平流层O3和中层大气H2O局地长期变化的影响。