热带和副热带大气准双周振荡特征对西北太平洋台风路径的影响

Impacts of Atmospheric Quasi-biweekly Oscillation of Tropical and Subtropical on Typhoon Tracks in WNP

根据美国联合台风预警中心热带气旋的数据（1979—2010年）以及NCEP/NCAR再分析风场和高度场的资料,从气候学角度分析了近32年夏季西北太平洋3类路径台风的大气准双周振荡的特征,并合成分析了6~10月3类路径台风生成时刻的原始环流、低频环流以及QBWO周期内低频环流的演变过程,结果表明：对流层低层至中层的大气存在明显的10~20 d准双周振荡特征,这对西北太平洋台风路径的预报有很好的指示作用;低频环流的演变特征表明,在西北太平洋地区,QBWO是通过低频气旋和低频反气旋来影响南海的季风槽以及副热带高压的强度和位置,进而对台风的生成位置和移动路径产生影响;菲律宾以东低纬度地区生成的低频气旋易于台风的生成,低频气旋的正涡度带走向和移动趋势预示着台风未来的移动方向;另外,在副热带地区同样存在着一支自西向东传播的大气准双周振荡波列,热带与副热带大气准双周振荡的相互作用对台风的路径产生了重要影响,这对台风路径的预报有较好的参考意义.

From the angle of climatology,the tropical cyclones（TCs） data from the American Joint Typhoon Waring Center（JTWC） and wind and height reanalysis data from NCEP / NCAR were used to discuss the modulation of typhoon tracks over the Western North Pacific by the atmospheric quasi-biweekly oscillation（QBWO）in the summer（June through October） for the nearly 32 years.The original circulation,low-frequency circulation,and the evolution of low-frequency circulation in the period of the atmospheric QBWO were analyze by the methods of composite analysis.The results showed that the atmospheric have the characteristics of QBWO;the atmospheric QBWO affects the intensity and position of monsoon trough and subtropical high pressure by the lowfrequency cyclone and low-frequency anticyclone,thus affects the formed location and movement of typhoon tracks;the low-frequency cyclone east of the Philippines is a more conducive condition for the formation of typhoons,the positive vorticity zone of low-frequency cyclone affects the movement of typhoon;additionally,the atmospheric QBWO eastward propagation in the subtropics also affects the typhoon tracks.The interaction of tropical and subtropical QBWO plays an important role for the typhoon tracking.