Determination of the effect of initial inner-core structure on tropical cyclone intensification and track on a beta plane

作者：Chen, Guanghua^*

来源：Advances in Atmospheric Sciences, 2016, 33(8): 945-954.

DOI：10.1007/s00376-016-5241-9

• inner-core structure
• tropical cyclone
• intensification
• track
• beta plane

The sensitivity of TC intensification and track to the initial inner-core structure on a beta plane is investigated using a numerical model. The results show that the vortex with large inner-core winds (CVEX-EXP) experiences an earlier intensification than that with small inner-core winds (CCAVE-EXP), but they have nearly the same intensification rate after spin-up. In the early stage, the convective cells associated with surface heat flux are mainly confined within the inner-core region in CVEX-EXP, whereas the vortex in CCAVE-EXP exhibits a considerably asymmetric structure with most of the convective vortices being initiated to the northeast in the outer-core region due to the beta effect. The large inner-core inertial stability in CVEX-EXP can prompt a high efficiency in the conversion from convective heating to kinetic energy. In addition, much stronger straining deformation and PBL imbalance in the inner-core region outside the primary eyewall ensue during the initial development stage in CVEX-EXP than in CCAVE-EXP, which is conducive to the rapid axisymmetrization and early intensification in CVEX-EXP. The TC track in CVEX-EXP sustains a northwestward displacement throughout the integration, whereas the TC in CCAVE-EXP undergoes a northeastward recurvature when the asymmetric structure is dominant. Due to the enhanced asymmetric convection to the northeast of the TC center in CCAVE-EXP, a pair of secondary gyres embedded within the large-scale primary beta gyres forms, which modulates the ventilation flow and thus steers the TC to move northeastward.

• 出版日期2016-8
• 单位中国科学院大气物理研究所