吴晓红,王绍武. 1996. 对流层大气环流的甚低频振荡[J]. 气象学报, 54(4):427-436, doi:10.11676/qxxb1996.044 |
对流层大气环流的甚低频振荡 |
VERY LOW FREQUENCY OSCILLATIONS IN THE VARIATIONS OF TROPOSPHERIC ATMOSPHERIC GENERAL CIRCULATION |
投稿时间:1994-12-19 修订日期:1995-05-22 |
DOI:10.11676/qxxb1996.044 |
中文关键词: 大气环流 年际变率 气候诊断 |
英文关键词:General circulation Interannual variablity Climate dignostics |
基金项目:《气候动力学和气候预测理论研究》项目 |
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中文摘要: |
对1951-1992共42a500hPa北半球高度场的月平均资料进行了纬圈谐波分析,计算了35°N与55°N超长波振幅及位相,以及35-55°N北半球月平均纬向风距平百分比.对超长波振幅及纬向风距平百分比做了小波转换.结果表明,对流层大气环流变化中存在3种准周期性的甚低频振荡:1.年代际的振荡;2.准2a周期振荡(QBO);3.半年韵律.同时发现对流层QBO和平流层赤道纬向风QBO之间可能没有联系. |
英文摘要: |
Based on the monthly mean 500hPa maps over the Northern Hemisphere for 42 years(1951-1992),zonal harmonic analysis at 35°N and 55°N were carried out and westerly intensities between 35-55°N were calculated.Meanwhile,wavelet transform of percentage departures of westerlies and relative amplitudes of ultra-long wave were analyzed.Then,three kind of very low frequency oscillations were identified in the variations of tropospheric general circulation.1.Interdecadal oscillation;2.Interannaual oscillation (QBO)and 3.One-year oscnlation. Interdecadal oscillation maybe exists in wave-1 with 30-40 year oscillation and wave-3 with 20-year oscillation at 350N.QBO with 2.5-2.6 year oscillation were showed in westerlies as well as wave-2 and wave-3 at 550N.but no any direct relationship with stratopheric QBO(2.2 year) was found out.Maybe,the QBO in middle troposphere is caused by the interactions between the atmosphere and ocean or between the atmosphere and land surface.It may belong to auto-oscillation of the climate system.After wavelet transform,the one-year oscillation in some ultra-long waves and westerlies were more outstanding.It reflects a kind of rhythm in atmosphere.such as,arm-winter and cool-summer and vice versa.It is also an adjustment inner the climate system,which closely relates to the seasonal course of the general circulation. |
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