北半球冬季准定常行星波的三维传播及其年际变化

The Three-Dimensional Propagation of Quasi-Stationary Planetary Waves in the Northern Hemisphere Winter and Its Interannual Variations

作者回顾了应用叶笃正先生所创立的Rossby波频散理论 ,来研究准定常行星波在三维大气的能量频散以及在北半球冬季三维大气中的传播规律 ,并应用NCEP NCAR再分析资料和由大气环流数值模拟所得的模式资料的 4 0年风场、温度场资料计算了冬季北半球准定常行星波的E P通量。计算结果表明了北半球冬季准定常行星波在三维大气传播具有沿两支波导的传播特征 ,这与从理论分析所得的结果相吻合。作者还分析了冬季准定常行星波的E P通量分布的年际变化 ,分析结果表明了准定常行星波在北半球冬季三维大气中传播的这两支波导有明显的年际振荡 ;并且 ,从冬季准定常行星波的E P通量辐散辐合的年际变化与北极涛动的年际变化相比较 ,发现准定常行星波两支波导的年际振荡直接影响着北极涛动 (AO) ,因而说明了准定常行星波活动的年际变化可以影响对流层的气候变化。

A review is firstly given on the energy dispersion and the winter propagation of quasi-stationary planetary waves in global three-dimensional atmosphere, which were studied based on the energy dispersion of Rossby-waves formulated by Prof. Ye Duzheng. Then based on the NCEP/NCAR reanalysis data and the AGCM simulation data, the E-P flux of quasi-stationary planetary waves is calculated from 40 years winter wind and temperature data. The feature of E-P flux indicated that the quasi-stationary planetary waves propagate along two wave guides in the Northern Hemisphere winter. This is consistent with our theoretical analysis. The interannual variations of E-P flux are also studied for the quasi-stationary planetary waves, and the results present that the two wave guides for the quasi-stationary planetary waves evidently have interannual oscillation. Moreover, by comparing the interannual variations between the E-P flux divergence for the quasi-stationary planetary waves and the Arctic Oscillation, it is found that the oscillation of two wave guides for the quasi-stationary planetary waves has close influence on the Arctic Oscillation on the interannual timescale. Therefore, the interannual variations of quasi-stationary planetary wave activity can have an impact on the tropospheric climate variability.