论文部分内容阅读
基于POM诊断模型,用GDEM气候态温盐资料,对南海环流进行诊断计算.结果表明,南海北部普遍存在跨陆坡运动且具有明显空间分布特征.从水平和垂直断面分布可知,较强的跨陆坡运动发生于浅水陆坡和海底地形急剧变化的海区.跨陆坡运动引起近岸陆架与外洋之间的水交换,其输运量估算为:沿200,500和1000 m等深线断面的跨陆坡体积输运年平均值分别为9.4,15.8,-2.1 Sv,热含量输运的年平均值分别为0.78,0.84,-0.22 PW,盐含量输运的年平均值分别为342.5,575.0,-76.0 Gg s~(-1).这3处断面之间水体产生辐聚或辐散,造成显著的跨陆坡输运.跨陆坡运动同时伴随着热盐输运,即有大量的热量和盐分向陆架海区输送,而少量向外洋输送,且沿200和500 m等深线断面的跨陆坡输运存在冬强夏弱的季节差异.200~500 m等深线之间的海区主要为向陆架方向的跨陆坡输运,而500~2000 m等深线之间的海区主要为向外洋方向的输运.陆坡流中跨陆坡运动成分不可忽视,占15%~20%.正压涡度平衡方程逐项分析发现,地形与斜压联合效应项、位势涡度平流项、对流和扩散项对跨陆坡运动起主要贡献.地形与斜压的相互作用是跨陆坡运动产生的主要因素,且在118°E以东区域对跨陆坡运动起显著的增强作用.
Based on the POM diagnosis model and the GDEM climate and temperature and salinity data, the South China Sea circulation is diagnosed and calculated. The results show that there are widespread trans-slope movements in the northern South China Sea and have obvious spatial distribution. From the horizontal and vertical profiles, The movement occurred in shallow sea slopes and sea areas with steep terrain changes.The trans-continental movement caused water exchange between the near-shore continental shelf and the ocean, and the transport volume was estimated as trans-slope volume transport along the 200, 500 and 1000 m isobaths The average annual values were 9.4, 15.8 and -2.1 Sv, respectively, and the annual mean values of heat transport were 0.78, 0.84 and -0.22 PW, respectively. The average annual transport values of salt content were 342.5, 575.0 and -76.0 Gg s ~ (-1) .Which of the three sections have convergent or divergent water, resulting in significant cross-slope transport.Translope movement accompanied by the transport of hot salt, that is, a large amount of heat and salt transported to the shelf sea area, While a small amount is transported to the outside of the ocean, and there is a seasonal difference in winter and strong summer weakness across the slope along the 200 and 500 m isometric deep sections. The sea area between 200 ~ 500 m isobaric mainly transcontinental slope to the shelf However, the sea area between 500 ~ 2000 m isobaric line is mainly The oceanic cross-slope motion component can not be neglected, accounting for 15% ~ 20%. The positive pressure vorticity balance equation is analyzed one by one and the results show that the combined effect of topography and baroclinic pressure, potential vorticity advection, convection And the diffusion term contribute to the trans-continental movement.The interaction between topography and baroclinic pressure is the main factor of trans-continental motion, and enhances the trans-continental motion in the east of 118 ° E.