Dependence of tropical cyclone weakening rate in response to an imposed moderate environmental vertical wind shear on the warm-core strength and height of the initial vortex

This study investigated the dependence of the early tropical cyclone (TC)
weakening rate in response to an imposed moderate environmental vertical
wind shear (VWS) on the warm-core strength and height of the TC vortex
using idealized numerical simulations. Results show that the weakening of
the warm core by upper-level ventilation is the primary factor leading to
the early TC weakening in response to an imposed environmental VWS. The
upper-level ventilation is dominated by eddy radial advection of the
warm-core air. The TC weakening rate is roughly proportional to the
warm-core strength and height of the initial TC vortex. The boundary-layer
ventilation shows no relationship with the early weakening rate of the TC
in response to an imposed moderate VWS. The findings suggest that some
previous diverse results regarding the TC weakening in environmental VWS
could be partly due to the different warm-core strengths and heights of
the initial TC vortex.