Numerical model for global atmospheric constituent change and development of high-speed execution method by parallel processing

本研究项目的目的是首先建立一个全球对流层成分变化的数值模式(大气成分输送、扩散、化学和沉积的三维模式)，并与大气全球环流模式(GCM)相耦合来预测全球气候变化；其次对数值模式进行验证，将其应用于东亚酸雨和黄沙远程输送的区域空气质量问题。结合湍流扩散、气液相化学、干湿沉积等相关过程的各个子模式，采用球坐标系，构建了一个统一的全球大气成分变化数值模式。在这里，我们将重点放在气溶胶模式上，因为预测气溶胶对全球警报的影响的不确定性远远大于气体成分的影响，并使模式在Predi…中尽可能准确。更多地了解气溶胶和温室气体的行为以及它们之间的相互作用。此外，为了大大缩短计算时间，开发了并行处理和矢量化处理程序，并将所得到的计算方案和计算机系统应用于实际。在各种气溶胶过程中，我们重点讨论了气溶胶的源-汇、反应和辐射强迫三个过程。在源-汇过程中，对造成东亚地区独特空气质量的土壤沙尘的放空进行了精确的模拟。在气溶胶成核生长和气溶胶非均相反应子模式中，精确地处理了气体和气溶胶之间的热力学平衡，并对达到平衡态的速率和气溶胶生长进行了广泛的模拟。在辐射强迫模式中，特别考虑了气溶胶对云的形成和降水的间接辐射强迫作用，并以东亚地区酸雨和黄沙的长距离输送为例，成功地预报了黄沙对酸雨的中和作用和大气污染物排放增加引起的降水酸度的年变化。较少

The purpose of this research project is firstly to develop a numerical model of global tropospheric constituent change (three-dimensional model of transport, diffusion, chemistry and deposition of atmospheric constituents) which should be coupled with an atmospheric global circulation model (GCM) to predict the global climate change, and secondly to validate the numerical model, applying it to the regional air quality problems on the long range transport of acid rain and yellow sand in East Asia.Combining all the sub-models for relevant processes such as turbulent diffusion, gas-and liquid-phase chemistry, dry and wet depositions, and adopting the spherical coordinate system, we constructed a unified numerical model of global atmospheric constituent change. Here, we focused our concentration on the aerosol modeling, since uncertainty in predicting aerosol effects on the global warning are much larger than that of gaseous constituents, and made the model as accurate as possible in predi … More cting the behaviors of both aerosol and greenhouse gases and interactions between them. In addition, in order to achieve a large reduction of the **cution time, a procedure for parallel processing as well as that for vectoralization was developed, and the resulted calculation scheme and computer system were adopted for practical use.Of the various aerosol processes, we focused on three processes, i. e., aerosol source-sink, reaction and radiative forcing. In the source-sink process, an accurate modeling was performed for the deflation of soil dust, which brought about the peculiar air quality in East Asia. In the aerosol nucleation and growth and aerosol heterogeneous reaction sub-model, thermodynamic equilibrium between gas and aerosol was treated accurately and the rate attaining at the equilibrium state and aerosol growth were modeled extensively. In the radiative forcing sub-model, a special attention was paid on the so-called indirect radiative forcing due to aerosol effects on the cloud formation and precipitation.As a case study, long range transport of acid rain and yellow sand in East Asia was simulated, and it was shown that the effects of the yellow sand on neutralizing the acid rain and annual change of the precipitation acidity due to the emission increase of air pollutants were predicted successfully. Less