非绝热加热对赤道地区平均纬向环流的作用——非线性响应

ON THE EFFECT OF DIABATIC HEATING ON MEAN ZONAL CIRCULATION IN THE EQUATORIAL ZONE——A NONLINEAR RESPONSE

本文设计了一个两层非线性原始方程模式,做低谱展开,求出非线性方程组的解;讨论了在外参数变化情况下解及其相应环流的演变;并与线性响应作了对比。此外,还讨论了定常解的稳定性。 主要结论是:(1)非绝热加热各分量在非线性响应中能强迫出更为接近实际的赤道地区平均纬圈环流圈。(2)在非线性响应中,潜热加热对纬圈环流的作用是最主要的。随着外参数——湿度的变化,解出现突变现象,其对应的赤道地区平均纬圈环流从一个定常态变到另一个定常态;其中对流潜热的作用最为明显,感热加热的作用是次要的。(3)在非线性响应和线性响应中,辐射加热对环流的作用不同;潜热加热对环流的作用相似,但在前者中它要强得多。

In this paper, a 2-layer nonlinear primitive equations model is developed and evolved at low spectra for the solution of nonlinear equation groups. The evolution of the solutions and their corresponding circulation are discussed with changing external parameters and they are compared with linear response. In addition, the stability of constant solution is studied. Main conclusions: (1) A more realistic mean zonal equatorial circulation is forced by components of the diabatic heating in the non-linear response. (2) In this response, warming by latent heat exerts a dominant effect on zonal circulation. Abrupt changes in the solutions can occur with the variation of external parameters. Their corresponding zonal circulation changes from one constant state to another, in which latent heat from convection plays a dominant role, followed by warming by sensible heat. (3) The effects of radiation heating on circulation differ for nonlinear and linear responses; warming by latent heat has similar effects on circulation, though much stronger for nonlinear response.