外强迫因子变化在2003年夏季旱涝预测中的作用

Impact of extra-forcing for prediction of drought and flood in summer 2003

利用中国科学院大气物理研究所大气科学和地球流体力学数值模拟实验室研发的全球海洋-大气-陆面过程气候系统耦合模式(IAP/LASG GOALS 4.0),对比分析了考虑和不考虑气候的外强迫因子(太阳活动、温室气体及硫酸盐气溶胶)变化对2003年夏季中国区域的短期气候预测的影响.结果发现,由于外强迫因子变化的影响,模式模拟的中国区域2003年夏季降水距平的分布比不考虑这种变化时更接近实况,它有效地改善了无外强迫变化时模式模拟预测的中国区域降水不真实偏大的缺点,使一些地区的模拟降水量值减小,范围扩大,位置北抬.更重要的是,由于考虑了外强迫的变化,GOALS耦合模式很好地模拟出了2003年夏季淮河流域较大的降水正距平区,同时相应的500 hPa环流场的模拟也有较大的改进.

The effects of short-term climate prediction are compared and analysed over China in summer 2003 using the coupled model with and without considering extra-forcing factors （such as greenhouse gases, solar activity, and sulfate aerosols, etc）. It is the fourth version coupled model, Global Ocean-Atmosphere-Land System model （GOALS 4.0）, developed by State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences. The simulations show that the prediction of precipitation distribution with variations of extra-forcing is better than without extra-forcing and closer to observations. In the simulation without extra-forcing, precipitation is overestimated or underestimated in some areas of northern China, and the wet center is slightly shifted southward in southern China, But in the simulation with extra-forcing, the pattern is more similar to the observation. For example, the strength of wet center in northem China is reduced and the center in southern China is boosted northward. The simulation successfully predicts the flood in the Huaihe River basin in summer 2003. Because of impact of extra-forcing, the simulation can improve the case that the predicted precipitation is untrue in northem China, especially in Xinjiang. So, it should not be neglected to consider variations of extra-forcing factors in short-term climate prediction using the climate coupled model.