Marine & Environmental Sciences Faculty Articles

ORCID

0000-0001-6519-1547

Document Type

Article

Publication Title

Journal of Geophysical Research Oceans

ISSN

2169-9291

Publication Date

12-2017

Keywords

Tropical cyclone, Rapid intensification, Rapid decline, Sea surface, Drag coefficient, Two-phase environment

Abstract

Tropical storm intensity prediction remains a challenge in tropical meteorology. Some tropical storms undergo dramatic rapid intensification and rapid decline. Hurricane researchers have considered particular ambient environmental conditions including the ocean thermal and salinity structure and internal vortex dynamics (e.g., eyewall replacement cycle, hot towers) as factors creating favorable conditions for rapid intensification. At this point, however, it is not exactly known to what extent the state of the sea surface controls tropical cyclone dynamics. Theoretical considerations, laboratory experiments, and numerical simulations suggest that the air-sea interface under tropical cyclones is subject to the Kelvin-Helmholtz type instability. Ejection of large quantities of spray particles due to this instability can produce a two-phase environment, which can attenuate gravity-capillary waves and alter the air-sea coupling. The unified parameterization of waveform and two-phase drag based on the physics of the air-sea interface shows the increase of the aerodynamic drag coefficient with wind speed up to hurricane force ( m s−1). Remarkably, there is a local minimum—“an aerodynamic drag well”—at around m s−1. The negative slope of the dependence on wind-speed between approximately 35 and 60 m s−1favors rapid storm intensification. In contrast, the positive slope of wind-speed dependence above 60 m s−1 is favorable for a rapid storm decline of the most powerful storms. In fact, the storms that intensify to Category 5 usually rapidly weaken afterward.

DOI

10.1002/2017JC013435

Volume

122

Issue

12

First Page

10174

Last Page

10183

Comments

©2017. The Authors. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Additional Comments

NOAA award #: NA15OAR4310173

Peer Reviewed

Find in your library

Share

COinS