Is the State of the Air-Sea Interface a Factor in Rapid Intensification and Rapid Decline of Tropical Cyclones?

Autor: Soloviev AV; Halmos College of Natural Sciences and Oceanography Nova Southeastern University Dania Beach FL USA.; Rosenstiel School of Marine and Atmospheric Science University of Miami Miami FL USA., Lukas R; School of Ocean and Earth Sciences and Technology University of Hawaii at Manoa Honolulu HI USA., Donelan MA; Rosenstiel School of Marine and Atmospheric Science University of Miami Miami FL USA., Haus BK; Rosenstiel School of Marine and Atmospheric Science University of Miami Miami FL USA., Ginis I; Graduate School of Oceanography University of Rhode Island Narragansett RI USA.
Jazyk: angličtina
Zdroj: Journal of geophysical research. Oceans [J Geophys Res Oceans] 2017 Dec; Vol. 122 (12), pp. 10174-10183. Date of Electronic Publication: 2017 Dec 28.
DOI: 10.1002/2017JC013435
Abstrakt: 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 C d with wind speed up to hurricane force ( U 10 ≈ 35 m s -1 ). Remarkably, there is a local C d minimum-"an aerodynamic drag well"-at around U 10 ≈ 60 m s -1 . The negative slope of the C d dependence on wind-speed between approximately 35 and 60 m s -1 favors rapid storm intensification. In contrast, the positive slope of C d 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.
(© 2017. The Authors.)
Databáze: MEDLINE
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