Two Modes of the Silk Road Pattern and Their Interannual Variability Simulated by LASG/IAP AGCM SAMIL2.0  

作　　者：宋丰飞 周天军 王璐 

机构地区：[1]State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences [2]University of Chinese Academy of Sciences [3]Climate Change Research Center, Chinese Academy of Sciences [4]National Satellite Meteorological Center

出　　处：《Advances in Atmospheric Sciences》2013年第3期908-921,共14页大气科学进展（英文版）

基　　金：supported jointly by National Program on Key Basic Research Project(Grant No.2010CB951904);the"Strategic Priority Research Program-Climate Change:Carbon Budget and Related Issues"of the Chinese Academy of Sciences(Grant No.XDA05110301);the National Natural Science Foundation of China(Grant Nos.40890054 and 41125017)

摘　　要：In this study, two modes of the Silk Road pattern were investigated using NCEP2 reanalysis data and the simulation produced by Spectral Atmospheric Circulation Model of IAP LASG, Version 2 （SAMIL2.0） that was forced by SST observation data. The horizontal distribution of both modes were reasonably reproduced by the simulation, with a pattern correlation coefficient of 0.63 for the first mode and 0.62 for the second mode. The wave train was maintained by barotropic energy conversion （denoted as CK） and baroclinic energy conversion （denoted as CP） from the mean flow. The distribution of CK was dominated by its meridional component （CKy） in both modes. When integrated spatially, CKx was more efficient than its zonal component （CKx） in the first mode but less in the second mode. The distribution and efficiency of CK were not captured well by SAMIL2.0. However, the model performed reasonably well at reproducing the distribution and efficiency of CP in both modes. Because CP is more efficient than CK, the spatial patterns of the Silk Road pattern were well reproduced. Interestingly, the temporal phase of the second mode was well captured by a single-member simulation. However, further analysis of other ensemble runs demonstrated that the successful reproduction of the temporal phase was a result of internal variability rather than a signal of SST forcing. The analysis shows that the observed temporal variations of both CP and CK were poorly reproduced, leading to the low accuracy of the temporal phase of the Silk Road pattern in the simulation.In this study, two modes of the Silk Road pattern were investigated using NCEP2 reanalysis data and the simulation produced by Spectral Atmospheric Circulation Model of IAP LASG, Version 2 （SAMIL2.0） that was forced by SST observation data. The horizontal distribution of both modes were reasonably reproduced by the simulation, with a pattern correlation coefficient of 0.63 for the first mode and 0.62 for the second mode. The wave train was maintained by barotropic energy conversion （denoted as CK） and baroclinic energy conversion （denoted as CP） from the mean flow. The distribution of CK was dominated by its meridional component （CKy） in both modes. When integrated spatially, CKx was more efficient than its zonal component （CKx） in the first mode but less in the second mode. The distribution and efficiency of CK were not captured well by SAMIL2.0. However, the model performed reasonably well at reproducing the distribution and efficiency of CP in both modes. Because CP is more efficient than CK, the spatial patterns of the Silk Road pattern were well reproduced. Interestingly, the temporal phase of the second mode was well captured by a single-member simulation. However, further analysis of other ensemble runs demonstrated that the successful reproduction of the temporal phase was a result of internal variability rather than a signal of SST forcing. The analysis shows that the observed temporal variations of both CP and CK were poorly reproduced, leading to the low accuracy of the temporal phase of the Silk Road pattern in the simulation.

关 键 词：Silk Road pattern barotropic energy conversion baroclinic energy conversion SST 

分 类 号：P434[天文地球—大气科学及气象学]