Comparative analysis of kinetic energy budget of Typhoons Yagi and Rumbia

Abstract

In this paper, the ERA-Interim reanalysis data at six-hourly intervals (with a horizontal resolution of 0.25° × 0.25°) and typhoon best track datasets are used to conduct a comparative kinetic energy budget analysis of Typhoon Yagi and Rumbia during their lifecycles in 2018. At the same time, the contributions of divergent wind and rotating wind to the kinetic energy budget in different quadrants are analyzed, and the relative importance of the components of rotating wind energy and divergent wind energy represented by Kr and Kd in the kinetic energy budget is studied. Different from the previous kinetic energy budget analysis of the whole target area, this paper studies Kr and Kd in the four quadrants around the typhoon center to reveal their respective contributions to the development of the typhoon. The results show that: (1) On the whole, the rotational wind energy Kr is the largest, and the distribution is relatively consistent with the total kinetic energy K0. (2) The variation trend of divergent wind energy Kd in the lower layer can better reflect the intensity change of TCs. (3) From the comparative analysis of the deviation term vr∗vd, ''Rumbia'' weakens to the lowest in the northwest, while the corresponding northeast direction is the maximum at this time, which corresponds to the beginning of the Northeast turning of ''Rumbia''. (4) Through further analysis and comparison, it is found that T1 and T3 are mainly positive in the low layer, and their contributions mainly come from T1d and T3d.

Keywords

• Typhoon
• Kinetic energy budget
• Rotating wind kinetic energy
• Divergent wind kinetic energy