【摘要】 采用诊断方法研究了El Ni(?)o和La Ni(?)a事件与北半球中高纬大气低频振荡。用1950-2003年北半球中高纬逐日500 hPa高度场资料进行功率谱分析得出：(1)ENSO事件对中高纬大气低频振荡有调频作用,即夏季低频振荡较弱,冬季低频振荡较强。(2)El Ni(?)o(La Ni(?)a)事件有使低频振荡周期缩短(延长)的趋势。(3)ENSO事件对中高纬大气低频振荡的调频作用比中低纬明显。更多还原

【Abstract】 A diagnostic analysis is carried out to investigate the relationship of ENSO episodes and the atmospheric low-frequency oscillation (LFO) in the mid-high latitudes of the Northern Hemisphere.The power spectral analysis is performed for the daily 500 hPa height field data in the mid-high latitudes of the Northern Hemisphere from 1950 to 2003.The results show that:(1) ENSO episodes have the frequency modulation effect on low-frequency oscillation (LFO) in the extra-tropical latitudes of the Northern Hemisphere,i.e.Intensity of low-frequency oscillation in winter is stronger than that in summer.(2) The main period of low-frequency oscillation show the shortened (lengthened) tendency during E1 Ni(?)o (La Ni(?)a) episodes.(3) The frequency modulation effect of ENSO episodes on atmospheric low-frequency oscillation (LFO) in the mid-high latitudes is clearer than that in the mid-low latitudes.更多还原