大气科学2011，Vol.35Issue(5)：927-937,11.
瞬变天气涡旋对北大西洋涛动的增强效应
Enhancement of North Atlantic Oscillation by Transient Eddies
摘要
Abstract
Time series of the intensity of North Atlantic transient eddy activity and a daily index of the North Atlantic Oscillation (NAO) are calculated by using the NCEP/NCAR reanalysis data. The results suggest that peaks in the intensity of eddy activity are followed by strengthening of the NAO mode, accompanied by a collapse in eddy energy. To determine whether the interaction between eddies and low-frequency flow results in the transformation of synoptic-scale energy to low-frequency-scale energy, the eddy vorticity flux is used to investigate the transfer of vor-ticity and energy. The results show that transient eddies can induce low-frequency anomalies and that vorticity transfer can enhance the anomaly, resulting in an increase in the NAO index. However, eddies, low-frequency flow, and the vorticity flux show continuous variations, meaning that they cannot attain equilibrium all the time. Accordingly, the authors analyze the total contribution of stochastic eddies to the process that induces an NAO-like response toexternal forcing. The steady solution suggests that eddy forcing can induce a response more similar to the NAOmode.关键词
瞬变天气涡旋/北大西洋涛动/瞬变涡度通量Key words
transient eddy, NAO, eddy vorticity flux分类
天文与地球科学引用本文复制引用
张冬斌,金飞飞,李建平,丁瑞强..瞬变天气涡旋对北大西洋涛动的增强效应[J].大气科学,2011,35(5):927-937,11.基金项目
国家重点基础研究发展规划项目2010CB950400,国家自然科学基金资助项目41030961、40805022 （）
