IAP AGCM中短波辐射方案的改进研究II·短波辐射方案的改进

在Version 2的基础上,对短波辐射方案进行进一步的改进:引入了新增非灰体气体吸收效应、冰晶粒子形状效应和尺度效应以及云的不均匀性效应(称为Version 3)。数值模拟试验结果表明:Version 3能更好地模拟出全球冬、夏季的降水场、海平面气压场及地表气温场的主要分布特征,并且能相当准确地反映出这几个场的季节性变化特征。Version 3对这3个场的模拟能力明显优于原版本(Version 1)。此外,它对东亚地区的季风降雨具有很好的模拟能力,能较好地反映东亚区域降水的季节性变化。可见,Version 3为进一步研究云-辐射相互作用提供了很好的模式基础。本工作还清楚地表明,模式的进一步发展必须进行对相关物理过程中各个因子的更精确刻画,只有这样,模式才能得到更好的模拟能力。

The Study of the Improvement of the Solar Radiation Transfer Scheme in IAP AGCM Part II: The Improvement of Solar Radiation Scheme

On the base of Version 2,we have further improved its solar radiation scheme by introducing the influence of the additional weak solar absorption bands,the habit and size effects of ice crystals,and the effect of the mesoscale inhomogeneity of clouds.So a Version 3 of IAP AGCM-II is now for research and development.Numerical simulation results have shown that generally,Version 3 can successfully reproduce the East Asia monsoon climate,the mean observed January and July climatology and the annual cycle for most climate fields.Compared with the original version of IAP AGCM-II,Version 3 has better simulative abilities for precipitation,sea level pressure and surface ground air temperature.Especially,it has improved the simulations of the East Asia precipitation patterns and subtropical high in Pacific in July.Thus,Version 3 provides a better AGCM base for further studying cloud-radiation interactions and feedbacks in interannual and interseasonal climate variations.Our work also indicates that more reasonable treatment of physical process is key to improve the performance of AGCM.