热带太平洋地区HYCOM模式不同垂向坐标设置对比研究

A Comparative Study of HYCOM Different Vertical Coordinate Setting in the Tropical Pacific

基于挪威南森环境遥感中心改进的NERSC-HYCOM模式,对热带太平洋海域进行了多个不同垂向坐标设置的试验分析,探讨该海域不同垂向坐标设置对于模拟热带太平洋温度场和流场的影响,并设计了一个改进型方案.通过对比分析赤道海区海温、纬向流速的水平和垂直分布及其变化,得到以下主要结论:1)与密度相关的混合坐标模式对位密的选取是敏感的,NERSC-HYCOM模式应用于太平洋应选择适合太平洋的位密设置.2)具有较高垂向分辨率的单一z坐标或单一σ坐标模式能较好地模拟热带开阔大洋上层的温度场,但大洋边界处模拟效果稍差;单一σ坐标模式模拟的表层流场、双坐标σ-z模式以及上层z坐标分辨率不高的σ-z-iso混合坐标模式模拟的海温场和流场均不能令人满意.3)σ-z-iso混合坐标模式上层z坐标的分辨率对模拟效果影响较大,模拟热带太平洋海洋环流和海温应该采用较高上层z坐标分辨率的σ-z-iso混合坐标模式.

Based on Norwegian Nathan Environment Remote Sensing Center improved NERSC-HYCOM model,several different vertical coordinate setting tests on the tropical Pacific Ocean are made which discuss different vertical coordinates is set for the influence of the tropical Pacific Ocean temperature field and flow field and an improved scheme is designed on this area.Through the comparative analysis of the equator sea surface temperature（SST）and horizontal and vertical distribution and change of zonal flow velocity,the conclusions can be drawn as follows：1）Hybrid coordinate model related to the density is sensitive to the selection of potential density,NERSC-HYCOM model applied in the Pacific should choose suitable potential density setting for the Pacific;2）Single zcoordinate or singleσcoordinate model with high vertical resolution can well simulate tropical upper temperature field of the open ocean,but simulation effect in ocean border is a bit poor;singleσcoordinate model to simulate the surface of the flow field,double coordinateσ-z model andσ-z-iso hybrid coordinate model which has the low upper zcoordinate resolution to simulate the SST field and flow field are not satisfactory;3）Upper zcoordinate resolution ofσ-z-iso hybrid coordinate model has a great impact on the simulation result,so when to simulate the tropical Pacific Ocean circulation and SST,it should adopt higher upper zcoordinate resolution ofσ-z-iso hybrid coordinate model.