北太平洋Rossby波研究进展

Rossby Waves in the North Pacific Ocean:A Review

系统地阐述了北太平洋Rossby波在卫星观测、理论扩展及模型应用3个方面的研究成果。随着卫星观测技术的发展,明显地探测到海表面信号的Rossby波特征,且观测到波速在热带外大于自由Rossby波理论值。为解释这个波动加速现象,在自由Rossby波理论的基础上,考虑了大气强迫、非静止基流及海底地形等因子的作用,使得Rossby波的波动理论得到了扩展。而关于风应力强迫Rossby波的线性理论模型主要有3类:一阶斜压Rossby波模型、局地Ekman抽吸模型和Sverdrup平衡模型。这些模型被广泛地应用到北太平洋海表面高度和温度/密度跃层深度等要素变化的机理研究中,得到了不同的模型在大洋的不同区域有不同的作用等结论。最后,对线性Rossby波研究存在的问题进行了初步探讨,提出了需要进一步解决的新课题。

The baroclinic Rossby waves took a substantial role in the adjustment of dynamic processes in global ocean. The studies of the Rossby waves in the North Pacific Ocean were reviewed, focusing on the satellite observing, theories extended and models applied. Beside the satellite altimeter data detecting the ubiquitous Rossby waves in ocean, other oceanic surface signals （sea surface temperature, ocean color and sea surface salinity） could also reflect the planetary waves＇ characteristics, which suggested that the Rossby waves not only functioned in dynamics, but also acted on thermodynamics and biology. Moreover, at mid and high-latitude, the phase speeds of the ob- served waves were faster than those given by standard linear Rossby waves theory. The two extended theories explai- ning the speedup phenomena were presented. First, the Rossby waves were forced by wind stress and were coupled with the overlying atmosphere, so were not free. Second, the ocean＇s background state was not at rest, and also the ocean had a varying bottom. The linear dynamic models forced by wind stress were introduced, including the first baroclinic Rossby waves model, local Ekman pumping model and Sverdrup balance model. In particular, the appli- cations of these models in sea surface height and thermocline/pycnocline depth variability in the North Pacific O- cean were described in detail. Finally, the existing questions of linear Rossby waves theory were discussed, and outstanding issues were advanced.