Two Tales of Initializing Decadal Climate Prediction Experiments with the ECHAM5/MPI-OM Model
Two Tales of Initializing Decadal Climate Prediction Experiments with the ECHAM5/MPI-OM Model
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DOI：
10.1175/jcli-d-11-00633.1
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发表时间：
2012-12-15
影响因子：
4.9
通讯作者：
Marotzke, Jochem
中科院分区：
文献类型：
--
作者：
Matei, Daniela;Pohlmann, Holger;Marotzke, Jochem
本文研究了不同的海洋初始化策略对ECHAM5/ MPI-OM耦合模式进行的年代际预测实验预测能力的影响。海洋初始化吸收了两种不同海洋状态估计的三维温度和盐度异常，即德国贡献的海洋环流和气候估算（GECCO）的海洋再分析，以及NCEP-NCAR大气再分析强迫的MPI-OM海洋实验集。结果表明，北大西洋和地中海海表温度（SST）变化可以熟练地预测长达10年的未来，并且比未初始化模拟和持续预报更熟练。两种初始化方法的海温预测技能区域分布相似；然而，当使用预测技能测量的组合时，发现NCEP预测比GECCO预测的技能更高。对欧洲西北部、北非和亚洲中东部的地表气温进行了精确的预测。在海表温度和上层海洋热含量预测中，北大西洋次极环流区都是超越变暖趋势预测能力最高的区域。在这里，NCEP后估由于对观察到的可变性进行了更精确的初始化，因此提供了最好的结果。北大西洋气候可预测性的主要机制是动力起源，可归因于大西洋经向翻转环流的初始化，从而解释了高预测技能在第二候试验中的再次出现。本文的结果表明，海洋实验与观测到的大气状态的历史是一个简单但成功的替代策略，为未来十年的熟练气候预测初始化。
This paper investigates the impact of different ocean initialization strategies on the forecast skill of decadal prediction experiments performed with the ECHAM5/Max Planck Institute Ocean Model (MPI-OM) coupled model. The ocean initializations assimilate three-dimensional temperature and salinity anomalies from two different ocean state estimates, the ocean reanalysis of the German contribution to Estimating the Circulation and Climate of the Ocean (GECCO) and an ensemble of MPI-OM ocean experiments forced with the NCEP-NCAR atmospheric reanalysis. The results show that North Atlantic and Mediterranean sea surface temperature (SST) variations can be skillfully predicted up to a decade ahead and with greater skill than by both uninitialized simulations and persistence forecasts. The regional distribution of SST predictive skill is similar in both initialization approaches; however, higher skill is found for the NCEP hindcasts than for the GECCO hindcasts when a combination of predictive skill measures is used. Skillful predictions of surface air temperature are obtained over northwestern Europe, northern Africa, and central-eastern Asia. The North Atlantic subpolar gyre region stands out as the region with the highest predictive skill beyond the warming trend, in both SST and upper-ocean heat-content predictions. Here the NCEP hindcasts deliver the best results due to a more accurate initialization of the observed variability. The dominant mechanism for North Atlantic climate predictability is of dynamical origin and can be attributed to the initialization of the Atlantic meridional overturning circulation, thus explaining the re-occurrence of high predictive skill within the second pentad of the hindcasts experiments. The results herein demonstrate that ocean experiments forced with the observed history of the atmospheric state constitute a simple but successful alternative strategy for the initialization of skillful climate predictions over the next decade.