KITADA Toshihiro Toyohashi University of Technology, Professor, エコロジー工学系, 教授 (40093231)
KARASUDANI Takashi Kyushu Univ., Research Inst. for Applied Mechanics, Associate Professor, 応用力学研究所, 助教授 (30150527)
TATSUNO Masakazu Kyushu Univ., Research Inst. for Applied Mechanics, Associate Professor, 応用力学研究所, 助教授 (70038553)
HORIGUCHI Mitsuaki Kyoto Univ., Disaster Prevention Res. Inst, Research Associate, 防災研究所, 助手 (60190253)
ISHIKAWA Hirohiko Kyoto Univ., Disaster Prevention Res. Inst., Associate Professor, 防災研究所, 助教授 (60263159)
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
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