摘要
大气低频模态是导致中高纬地区季节及气候变化的主要因素,加强低频模态动力机制的认识对于提高短期气候预测水平具有十分重要的科研意义和应用价值。由于中高纬大气低频环流本身的复杂性,关于其动力机制的研究仍然是大气动力学中重点难点问题。本文简单回顾了激发维持低频模态的前两种机制,即:外源强迫、气流的纬向非均匀性对大气低频模态的影响。从观测事实和模式结果出发,着重介绍了瞬变波与基本气流相互作用激发维持低频模态的第三种机制,且详细阐述了线性假设条件下,瞬变波与基本气流相互作用的动力机制。本文最后针对瞬变波与基本气流相互作用研究中一些尚未解决的问题进行了讨论。
The low-frequency （LF） mode is the main factor with respect to the seasonal and climatic variability over middle and high latitude. Emphasizing the dynamical mechanism of the LF mode has im- portant scientific meaning and application value in improving short-term climate forecasting level. Because of the complex character of the LF flow in middle-high latitude, its dynamical mechanism is still the key problem in the atmosphere dynamic studies. An brief overview from the previous two aspects is presented in this paper to explain the mechanism of the LF modes ： external source forcing, non-zonal flow instabili- ty. Based on the observations and model outputs, the third mechanism of the positive feedback role of synoptic eddy and low-frequency flow interaction （SELF） in maintaining the LF modes is introduced, moreover, under the linear hypothesis, the details of the dynamic mechanisms of the SELF are ex- plained. At last, some unsolved issues of the SELF are discussed in the end.
出处
《气象科学》
北大核心
2015年第6期799-806,共8页
Journal of the Meteorological Sciences
基金
国家自然科学基金资助项目(41475045)
国家自然科学基金重点资助项目(4030951)
南京信息工程大学人才启动经费(S8113071001)
关键词
大气环流
低频模态
大气动力学
研究进展
Atmospheric circulation
Low-frequency mode
Synoptic dynamics
Research pro-gress
