Comparisons of Four Methods for Tropical Cyclone Center Detection in a High-Resolution Simulation

Abstract

The tropical cyclone (TC) center position is often needed in the study of the innercore processes although there is currently no consensus on the definition of the TC center. While previous studies evaluated center-detecting methods in terms of the center position, vertical tilt and decomposed symmetric and asymmetric circulations, this study used the 1-km resolution output of the predicted Hurricane Wilma (2005) at 5minute intervals to evaluate the four TC centers that are frequently used in the diagnostic analysis of the inner-core dynamics processes: the pressure centroid center (PCC), the potential vorticity (PV) centroid center (PVC), the maximum tangential wind center (MTC) and the minimum pressure variance center (MVC) by focusing on the evolution of the small-scale track oscillation and vortex tilt. The differences in the detected center position and vertical tilt are generally small during the course of rapid intensification and eyewall replacement. The four methods all lead to similar small-scale track oscillations that rotate cyclonically around the mean track. While the MVC and PVC lead to a relatively smooth rotation, abrupt changes exist in the track oscillation of the MTC; the track oscillation of the PCC contains amplified embedded rotations that are associated with the PV mixing in the eye region. The tracks of the MVC and PVC relative to the lower-level center (vertical tilt) are generally smooth, while the relative tracks of the MTC and PCC contain abrupt changes. The MVC also leads to the strongest symmetric structure in the tangential wind, PV, and radial PV gradient in the eyewall region. This study suggests that the MVC should be selected in the study of inner-core processes.

Storm‐Scale and Fine‐Scale Boundary Layer Structures of Tropical Cyclones Simulated With the WRF‐LES Framework

“…The TC center is determined with a variational approach in which it is located until the maximum azimuthal-mean tangential wind speed is obtained (Wu et al, 2006). The detailed descriptions of the method and other TC center tracking methods can be found in the study from Yang et al (2020).…”

Sensitivity of the Tropical Cyclone Boundary Layer to Vertical Diffusion in a Turbulent Kinetic Energy‐Based Boundary Layer Parameterization Scheme at Gray‐Zone Resolution

“…In addition, it is crucial to note how the TC center was estimated, especially in high‐resolution simulations, considering the sensitivity of the various objective algorithms (Nguyen et al., 2014; Yang et al., 2020). Here, TC centers were calculated using the same method as in the WRF model.…”

Fine-Scale Structures in the Mid-Level Eyewall of Super Typhoon Rammasun (2014) Simulated With the WRF-LES Framework

“…In the following analysis, we will focus on the hourly output from 0300 UTC to 0700 UTC 18 July (3 h after the activation of the innermost domain and before landfall in Hainan Island at 0700 UTC 18 July). The TC center is defined as the minimum pressure variance center (Yang et al, 2020).…”