摘要
基于1992年10月至2000年12月的TOPEX/Poseidon和ERS-1/2卫星高度计资料,分析了周期短于150d的高频波动及其能量的空间分布特征.在功率谱密度计算基础上,分析特定频段所含能量占周期短于150d的高濒波动总能量的百分比,发现该频段最强振荡(下文称主振荡)所对应的周期从近赤道的1个月逐步增加至南北纬30°附近的4个月,进一步分析表明主振荡周期的这种变化是连续的,与西向行星Rossby波的相速随纬度增加而变慢相对应.主振荡所对应的周期在全球海洋中呈显著的带状分布.进而表明在14°N(S)附近60d周期的振荡除通常所认为的由于潮汐混淆所造成的虚假信号之外,主要是行星Rossby波形态的真实信号.
Based on TOPEX/Poseidon(T/P) and ERS?-1 and 2 satellite altimeter data between October 1992 and December 2000, high frequency oscillations with periods less than 150 d are analyzed and their spatial distributions are described. The ratio, instead of the energy itself, of the energy corresponding to certain frequency band from power spectrum relative to the total energy in the 20～143 d range is analyzed. The results show that the period of the most energetic oscillations in this band continuously increases with latitude from about 1 month near the tropics to about 4 months near 30°, in agreement with the latitudinal dependency of the phase speed of westward propagating Rossby waves, which dominate the variability in those latitudes. As a result, the global spatial distributions of the period of the dominant oscillations are largely zonal, with relatively small differences between different ocean basins. It suggests that the oscillations with periods around 60 d are mainly associated with Rossby waves except being often regarded as tidal aliasing.
出处
《海洋学报》
CAS
CSCD
北大核心
2004年第3期1-7,共7页
基金
国家重点基础研究发展规划资助项目--渤黄东海环流及其变异预测数值模式和海洋大气灾害应用(G1999043809).
关键词
带状分布
ROSSBY波
高度计
60
d周期的振荡
zonal distribution features
Rossby waves
altimetry
the oscillations with periods around 60 d
