气候模式中北太平洋海洋环流经向输运对比研究

发布时间：2019-06-10 18:15

【摘要】：本文首先利用气候态海洋资料(WOA13和Argo)温盐数据,通过地转流分析方法(P-vector),计算出北太平洋绝对地转流场,并对北太平洋基本环流结构进行描述分析。进一步,我们针对当前流行的耦合气候模式输出结果进行分析,探讨耦合气候模式中的北太平洋环流结构以及相应的海洋环流经向输运的模拟效果。海表面温度(SST)能够在一定程度上反应海洋环流的动力机制,我们为选择一套较精确的SST参考资料,利用大洋24航次的船载SST分别对微波遥感卫星TMISST和多源融合数据OSTIASST进行验证评估。结果发现OSTIASST与观测相比,误差远小于TMISST,所以本文最终选择OSTIASST作为模式中SST误差衡量标准。随后,我们定性比较了耦合气候模式和OSTIA数据集中的气候态SST分布。通过将WOA13和Argo资料(2004-2015)反演的绝对地转流与前人观测调查研究进行对比,得出在2000m以上的海洋中,Argo资料更能够反应北太平洋真实的平均环流结构。选用Argo资料反演的地转流作为参照,用来验证Sverdrup输运,结果表明Sverdrup输运只在北太平洋中东部适用。同样,本文分析了 CMIP5中8个气候中的地转流和Sverdrup经向输运,结果发现气候模式中的Sverdrup理论适用性同样较差。值得强调的是,气候模式中真实经向输运与Sverdrup对比发现大部分模式存在较大偏差,然而小部分低分辨率的模式反而误差较小。这说明大部分高分辨率模式中的真实流动不但受Sverdrup平衡理论等线性动力过程的影响,还受局地涡等非线性动力过程的影响,而低分辨率模式则无法模拟出非线性动力过程,使得模拟出的流场与Sverdrup理论更为接近。
[Abstract]:In this paper, based on the climatic ocean data (WOA13 and Argo) temperature and salt data, the absolute geostrophic flow field in the North Pacific is calculated by geostrophic flow analysis method (P-vector), and the basic circulation structure in the North Pacific is described and analyzed. Furthermore, we analyze the output results of the current popular coupled climate model, and discuss the circulation structure of the North Pacific Ocean in the coupled climate model and the simulation effect of the meridional transport of the corresponding ocean circulation. Sea surface temperature (SST) can reflect the dynamic mechanism of ocean circulation to a certain extent. In order to select a more accurate set of SST reference materials, Microwave remote sensing satellite TMISST and multi-source fusion data OSTIASST were verified and evaluated by ocean 24 shipborne SST. The results show that the error of OSTIASST is much smaller than that of TMISST, so OSTIASST is finally selected as the criterion of SST error in the model. Then, we qualitatively compare the climatic SST distribution between the coupled climate model and the OSTIA data set. By comparing the absolute geostrophic current inversed from WOA13 and Argo data (2004 / 2015) with previous observational investigations, it is concluded that Argo data can better reflect the real average circulation structure in the North Pacific Ocean in more than 2000m oceans. The geostrophic current inversed from Argo data is used as a reference to verify Sverdrup transport. The results show that Sverdrup transport is only suitable in the east-central North Pacific. Similarly, the geostrophic flow and Sverdrup meridional transport in eight climates in CMIP5 are analyzed in this paper. the results show that the applicability of Sverdrup theory in climate model is also poor. It is worth emphasizing that the real meridional transport in the climate model is compared with Sverdrup, and it is found that most of the models have large deviation, but the error of a small number of low-resolution models is small. This shows that the real flow in most high-resolution models is affected not only by linear dynamic processes such as Sverdrup equilibrium theory, but also by nonlinear dynamic processes such as local vortexes, while the low-resolution model can not simulate nonlinear dynamic processes. The simulated flow field is closer to Sverdrup theory.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P731.27

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