Tag: dynamics-physics-paper

Observed Relationships Between Tropical Cyclone Vortex Height, Intensity, and Intensification Rate

DesRosiers, A. J., Bell, M. M., Klotzbach, P. J., Fischer, M. S., & Reasor, P. D. (2023). Observed relationships between tropical cyclone vortex height, intensity, and intensification rate. Geophysical Research Letters, 50(8), e2022GL101877.

Abstract: As a tropical cyclone (TC) intensifies, the tangential wind field expands vertically and increases in magnitude. Observations and modeling support vortex height as an important TC structural characteristic. The Tropical Cyclone Radar Archive of Doppler Analyses with Recentering data set provides kinematic analyses for calculation of the height of the vortex (HOV) in observed storms. Analyses are azimuthally-averaged with tangential wind values taken along the radius of maximum winds. A threshold-based technique is used to determine the HOV. A fixed threshold HOV strongly correlates with current intensity. A dynamic HOV metric quantifies vertical decay of tangential wind with reduced dependency on intensity. Statistically significant differences are present between dynamic HOV values in groups of steady-state, intensifying, and rapidly-intensifying cases categorized by subsequent changes in pressure.

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Precipitation Processes and Vortex Alignment during the Intensification of a Weak Tropical Cyclone in Moderate Vertical Shear

Rogers, R. F., Reasor, P. D., Zawislak, J. A., & Nguyen, L. T. (2020). Precipitation Processes and Vortex Alignment during the Intensification of a Weak Tropical Cyclone in Moderate Vertical Shear. Monthly Weather Review, (2020).


The mechanisms underlying the development of a deep, aligned vortex, and the role of convection and vertical shear in this process, are explored by examining airborne Doppler radar and deep-layer dropsonde observations of the intensification of Hurricane Hermine (2016), a long-lived tropical depression that intensified to hurricane strength in the presence of moderate vertical wind shear. During Hermine’s intensification the low-level circulation appeared to shift toward locations of deep convection that occurred primarily downshear. Hermine began to steadily intensify once a compact low-level vortex developed within a region of deep convection in close proximity to a midlevel circulation, causing vorticity to amplify in the lower troposphere primarily through stretching and tilting from the deep convection…

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