摘要
用波数域动能方程分析了1986年夏季东亚阻塞高压的形成、维持和衰退过程.发现该夏季代表阻塞高压的波动是5波(长波),而不是2波(超长波).在阻高形成和维持阶段,波与波非线性相互作用向5波输送动能,使5波动能增大;而波与平均流的相互作用则使5波动能减小.在阻高维持阶段,有效位能向5波转换动能,维持阻高.波与平均流的相互作用却使5波维持.在阻高衰退阶段则完全相反,波与波相互作用项以及有效位能与动能转换项均为负值,使5波动能变小,阻高衰退.而波与平均流相互作用,却使高纬西风减小,有利阻高维持.
he formation, maintenance and decay processes of blocking high over East Asia in summer of 1986 are analysed by kinetic energy equations with various wavenumber domains. It is found that the representative wave number of blocking high is wavenumber 5 in the case, which is in the long wave domain, not wavenumber 2. During the formation and maintenance stages of blocking episodes, the kinetic energy at wavenumber 5 increases through the wavewave nonlinear interaction and decreases through the wavemean flow interaction. During the maintenance stage, the available poteneial energy at wavenumber 5 is transformed into kinetic energy as to maintain the blocking. These physical processes are reversed in the decay stage, but the wavemean flow interaction leads to the decreasing of westerlies in the high latitude, and maintaining the bloking high.
出处
《应用气象学报》
CSCD
北大核心
1998年第3期298-303,共6页
Journal of Applied Meteorological Science
基金
国家自然科学基金会
内蒙古气象局"内蒙西部夏季异常干旱的成因分析"课题
关键词
东亚阻塞高压
波数域
动能方程
波动能
Blocking high Wavenumber domain Kinetic energy equation Kinetic energy at wavenumber 5