Meso-beta-scale environment for the stationary band complex of vertically sheared tropical cyclones

摘要

The stationary band complex (SBC) is a distinct, quasi-stationary convective asymmetry outside the eyewall of a tropical cyclone (TC) and plays an important role for TC intensity. Seminal work by Willoughby et al. related the SBC to the kinematic boundary between the TC and its environment and proposed a formation mechanism for the SBC. These results have been derived from observational data that are limited in radial and azimuthal coverage. The current study revisits these results using data from an idealized numerical experiment, which are not subject to such limitations. Consistent with Willoughby et al., the SBC in the idealized experiment is located near the boundary between the TC's 'moist envelope' and the lower theta(e) environment. In contrast, however, the SBC is not associated with the kinematic boundary between the TC and the environmental flow. Furthermore, the proposed formation mechanism does not operate in the idealized experiment.