一个压力坐标下的海洋环流模式(英文)

• 作 者: 黄瑞新 金向泽 张学洪
• 出 处: Advances in Atmospheric Sciences
• 发表日期: 2001年01期
• 关键词: 海洋环流 压力坐标 质量守恒模式 非Boussinesq 有限差分格式 环流型 准稳态 守恒形式 气候研究 现场密度

作者们构造了一个新的、压力（ｐ）坐标下海洋环流模式。由于海底压力是随时间变化的，所用的垂直坐标实际上是ｐ－ｓｉｇｍａ坐标。模式的数值解满足一套能量守恒的有限差分格式。模式的最重要的新特点在于它是一个完全可压缩的海洋模式，没有采用Ｂｏｕｓｓｉｎｅｓｑ近似。新模式在以下几方面不同于现有的许多模式：１）精确的质量守恒形式：２）计算密度时使用的是现场的瞬时压力和ＵＮＥＳＣＯ的状态方程；３）动量方程的密度也使用现场密度；４）保持总能量守恒的差分格式。初始的试验表明模式程序运行顺畅且非常稳定。新模式模拟的准稳态环流型同现有模式是一致的，不过达到这种准稳态环流型的时间演变过程则很不一样。这种非Ｂｏｕｓｓｉｎｅｓｑ模式可以为气候研究和卫星观测提供更加精确的信息。

The authors constructed a new oceanic circulation model under pressure (p) coordinates. Since the seafloor pressure changes over time, the vertical coordinate used is actually the p-sigma coordinate. The numerical solution of the model satisfies a finite set of energy conservation equations. The most important new feature of the model is that it is a fully compressible ocean model that does not use the Boussinesq approximation. The new model differs from many existing models in the following ways: 1) Precise mass conservation: 2) Instantaneous pressure in the field and UNESCO’s state equation are used in calculating the density; 3) The momentum equation is also densified using the field density ; 4) to maintain the total energy conservation of the differential format. Initial experiments show that the model program runs smoothly and is very stable. The quasi-steady-state circulation model simulated by the new model is consistent with the existing model, but the time evolution of this quasi-steady-state circulation model is very different. This non-Boussinesq model provides more accurate information for climate studies and satellite observations.