GOALS模式对热带太平洋ENSO年际变化特征的模拟评估

THE EVALUATION OF THE ENSO-LIKE INTERANNUAL VARIATION IN THE GOALS/LASG MODEL

  • 摘要: 文中重点分析了中国科学院大气物理研究所LASG最新发展的全球大气环流谱模式(R42L9)与一全球海洋环流模式(T63L30)耦合形成的全球海洋-大气-陆面气候系统模式(GOALS/LASG)新版本已积分30a的模拟结果,通过与多种观测资料的对比分析,讨论了赤道太平洋海表温度(SST)的年际变化及其纬向传播、赤道东太平洋SST异常与其他洋面SST变化之间的遥相关关系、赤道太平洋浅表层海温的年际变化特征等研究内容。结果表明,GOALS模式模拟出了赤道太平洋SST异常出现不规则的年际变化特点;赤道东太平洋SST异常的向西传播过程;赤道太平洋混合层海温变化由西向东、由深层向浅层的传播过程;同时也模拟出了赤道东太平洋SST变化与赤道西太平洋以及与西南太平洋海温之间的反相关关系,与南印度洋和副热带大西洋SST之间的正遥相关关系等实际观测现象。但GOALS模式也存在明显的不足,如对赤道东、中太平洋SST异常的年际变化幅度明显偏小,没能模拟出赤道东太平洋的SST变化比赤道中太平洋强的特点;赤道太平洋SST从东向西的传播速度明显比实际观测慢得多,但混合层海温极值变化由西向东的传播速度明显比实际情况快得多;没能模拟出赤道东太平洋SST变化同西北太平洋SST的负相关和北印度洋海温变化的正相关现象,因此?

     

    Abstract: The features of the ENSO-like interannual variation of the sea surface and subsurface temperatures have been explored in the equatorial Pacific, their zonal propagation, and teleconnect ion based on 30-year integrat ion results of the new version of the global ocean-atmosphere-land system (GOALS) model at State Key Laboratory of Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of At mospheric Physics (LASG/IAP).In this model, the R42L9 at mospheric general circulation model (AGCM) is full coupled with the T63L30 ocean general circulation model between 40 S and 40 N. The results show that the GOALS model captures some obse-rvational phenomena. For example, the irregular interannual variation of the sea surface temperature (SST) in the equatorial Pacific, the anomalous SST in the equatorial eastern Pacific propagates west ward with time, the opposit edirection propagation process of the anomalous sea subsurface emperature in the equatorial Pacific from the west to the east and from the deep upward to the shallow layer, and the variation of the SST in the east of the equatorial Pacific are negatively correlated with that in the west and the south west of the Pacific and positively correlated with that in the South Indian Ocean and the subtropics of the At lantic. However, there still existevident biases in the GOALS model with reference to observations. For instance, the mag nitude of the interannual variability of the SST in the equat orial eastern and central Pacific is too small. The model cannot simulate the feature of larger mag nitude of the SST variation in the eastern Pacific than that in the central Pacific. The propagation velocity of the SST anomalies from the east to the west of the equatorial Pacific is much slower than that calculat ed from the observation dat a but the propagation of the subsurface temperature anomalies from the west to the east of the equatorial Pacific is faster than the observation. The teleconnections such that the SST anomalies in equatorial eastern Pacific is negatively correlated with that in the northwestern Pacific and the positive correlation with that in the northern Indian Ocean are not simulated by the GOALS model. Those modelerrors, there fore, influence the precipitation simulation in the South and Sout heast Asia.

     

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