Intermodel variability of future changes in the Baiu rainband estimated by the pseudo global warming downscaling method
Intermodel variability of future changes in the Baiu rainband estimated by the pseudo global warming downscaling method
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DOI：
10.1029/2009jd011803
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发表时间：
2009-12-31
影响因子：
4.4
通讯作者：
Inoue, Tomoshige
中科院分区：
文献类型：
--
作者：
Kawase, Hiroaki;Yoshikane, Takao;Inoue, Tomoshige
利用伪全球变暖降尺度方法（PGW-DS）对白峪雨带在全球变暖过程中的变化进行了评估。PGW-DS与传统的基于区域气候模式（RCM）的动力降尺度方法相似，但RCM的边界条件是通过将耦合环流模式（CGCMs）模拟的未来和现在气候的差值加入到一个控制期的6小时再分析数据中得到的。我们使用选择的耦合模式比对项目第3阶段（CMIP3）多模型数据集进行了多次PGW-DS运行，在6月份东亚地区获得了更好的性能，并使用选择的CGCM模型集合平均值（PGW-MME运行）进行了PGW-DS运行。PGW-MME和PGW-DS运行均显示白宇雨带降水增加，白宇雨带南移。PGW-MME运行与所有PGW-DS运行的平均值具有良好的相似性。这一事实表明，多个PGW-DS运行的平均值可以用单个PGW-DS运行代替，使用多选择的CGCM集合平均值，显著降低了计算开销。与GCM预估相比，PGW-DS运行降低了由GCM本身引起的白雨带模式间变率。
Changes in the Baiu rainband owing to global warming are assessed by the pseudo global warming downscaling method (PGW-DS). The PGW-DS is similar to the conventional dynamical downscaling method using a regional climate model (RCM), but the boundary conditions of the RCM are obtained by adding the difference between the future and present climates simulated by coupled general circulation models (CGCMs) into the 6-hourly reanalysis data in a control period. We conducted the multiple PGW-DS runs using the selected Coupled Model Intercomparison Project Phase 3 (CMIP3) multimodel data set, giving better performance around East Asia in June, and the PGW-DS run using the multiselected CGCM model ensemble mean (PGW-MME run). The PGW-MME and PGW-DS runs show an increase in precipitation over the Baiu rainband and the southward shift of the Baiu rainband. The PGW-MME run has good similarity to the average of all PGW-DS runs. This fact indicates that an average of the multiple PGW-DS runs can be replaced by a single PGW-DS run using the multiselected CGCM ensemble mean, reducing the significant computational expense. In comparison with the GCM projections, the PGW-DS runs reduce the intermodel variability in the Baiu rainband caused by the CGCMs themselves.