西北太平洋一次爆发性气旋的诊断分析和敏感性试验

Diagnostic analysis and sensitivity test of an explosive cyclone over northwestern Pacific

利用美国国家环境预报中心(NCEP)的FNL格点资料和大气数值模式WRF,对2012年1月11—13日发生于西北太平洋上的一次爆发性气旋过程进行诊断分析和数值模拟。气旋于1月11—12日在日本以东海域爆发性发展,经历2次转向后于13日在堪察加半岛附近减弱。研究表明,气旋发展中存在明显锋面结构,对流层高层的高位涡下传对气旋发展非常有利,气旋发展过程中伴随着一支低空急流的生成和发展,使辐合抬升更加明显。利用WRF模式对10日1800 UTC至13日0000 UTC气旋过程进行海温敏感性试验。结果表明,海温变化对气旋发展强度影响明显,但对气旋路径影响较小。

The FNL grid data from NCEP（ National Centers for Environmental Prediction） are utilized to analyze an explosive cyclone process occurred in the northwestern Pacific Ocean from 11 to 13 January2012. The Weather Research and Forecasting model（ WRF） is employed to simulate the explosive cyclone from 1800 UTC 10 to 0000 UTC 13 January 2012.The cyclone breaks out in the east of Japan from 11 to12 January and weakens near the Kamchatka Peninsula on 13 January after changing direction two times.Results of diagnostic analysis show that there exists a distinct frontal structure in the development of cyclone.The high potential vorticity in the upper troposphere extends downward to the surface,which is beneficial to the development of cyclone. The cyclone develops rapidly along with the formation and development of a low level jet,which leads to more distinct convergence and ascending. Results of SST sensitivity tests suggest that the change of sea surface temperature can obviously affect the development intensity of the cyclone,but it has little effect on the cyclonic path.