학술논문

The Unconventional Eyewall Replacement Cycle of Hurricane Ophelia (2005).
Document Type
Article
Source
Monthly Weather Review. Jul2021, Vol. 149 Issue 7, p2151-2170. 20p. 1 Color Photograph, 1 Chart, 14 Graphs.
Subject
*HURRICANES
*OCEAN temperature
*RADAR in aeronautics
*STRATUS clouds
*CONVECTIVE clouds
Language
ISSN
0027-0644
Abstract
Hurricane Ophelia (2005) underwent an unconventional eyewall replacement cycle (ERC) as it was a category-1 storm located over cold sea surface temperatures near 23°C. The ERC was analyzed using airborne radar, flight-level, and dropsonde data collected during the Hurricane Rainband and Intensity Change Experiment (RAINEX) intensive observation period on 11 September 2005. Results showed that the spinup of the secondary tangential wind maximum during the ERC can be attributed to the efficient convergence of absolute angular momentum by the midlevel inflow of Ophelia's dominantly stratiform rainbands. This secondary tangential wind maximum strongly contributed to the azimuthal mean tangential wind field, which is conducive for increased low-level supergradient winds and corresponding outflow. The low-level supergradient forcing enhanced convergence to form a secondary eyewall. Ophelia provides a unique example of an ERC occurring in a weaker storm with predominantly stratiform rainbands, suggesting an important role of stratiform precipitation processes in the development of secondary eyewalls. [ABSTRACT FROM AUTHOR]