摘要
通过诊断分析指出，８０年代菲律宾周围的对流活动２～４年周期振荡比较明显；北太平洋风暴轴中心有线性增强、偏北、偏东的趋势，２～４年周期振荡也比较明显；在２～４年时间尺度上，菲律宾周围对流活动的变化与北太平洋风暴轴的变化有密切联系：当菲律宾周围对流活动强（弱）时，北太平洋风暴轴中心偏强（弱）、偏东（西）、偏北（南）。诊断分析和数值模拟表明，产生这种联系的物理机制是，当菲律宾周围对流活动强（弱）时，在东亚－北太平洋－北美地区产生一个距平波列（ＡＮＡ），位于美国西海岸的正（负）距平及其北侧的负（正）距平，使气压梯度增大（减小），北太平洋急流和风暴轴中心强度增强（减弱）、北抬（南退）、东伸（西退）。
Diagnostic analysis shows that convective activities around the Philippines have a 2～4 year period oscillation in the 1980's The storm track in the North Pacific has a linear strengthing, northward and eastward trend, and the obvious 2～4 year period oscillation There are close connections between the anomaly of convective activities and the storm track variation in the North Pacific on the 2～4 year time scale The center of the storm track in the North Pacific is strong (weak), eastward (westward), northward (southward) when the convective activities around the Philippines are strong (weak) According to the analysis results of the diagnostic analysis and the numerical simulation, the physical mechanism producing this connection is considered to be a forced anomaly wave train from east Asia to North America via the North Pacific (ANA) when the convective activities around the Philippines are strong (weak) At the same time, both the positive (negative) anomaly in the west coast of the U S A and the negative (positive) anomaly to its north increase (decrease) the pressure gradient, so that the jet stream and storm track center in the North Pacific are strong (weak), northward (southward) and eastward (westward)
出处
《大气科学》
CSCD
北大核心
1997年第5期513-522,共10页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金
关键词
对流活动
北太平洋
风暴轴
西太平洋
年际变化
Philippines convective activity storm track in the North Pacific East Asia North Pacific North America teleconnection pattern (ANA) 2～4 year period oscillation
