Oceanic Response Observations due to Passing Tropical Cyclones: An Assessment of Drag and Sea Spray Parameterizations
Gallagher, Stephan, D
Jayne, Steven R.
Flierl, Glenn R.
MetadataShow full item record
In 2015, Air-Launched Autonomous Micro Observer float 9077 was intercepted by Hurricane Ignacio and revealed a 40 m isotherm depression preceding the traditional, well-documented upwelling response. To replicate this unique and apparent downwelling ahead of Hurricane Ignacio and three othersﾗIrma, Florence and Michael, the Price-Weller-Pinkel model permitted comparisons of tropical cyclone intensity indices and vertical velocity. When modeling the stress, two other traditional ideas were challenged. First, many legacy drag coefficients linearly increase with wind speed, while the modern variety maximize near tropical cyclone strength. Second it is believed sea spray droplets are sheared off large wave crests, quickly accelerate, but upon reentry, dampen smaller waves while fluxing considerable momentum to the ocean. However, many models bulk parameterize air-sea interaction processes with a legacy drag coefficient and omit spray. Therefore, this study aimed to simulate the aforementioned downwelling using seven legacy/modern drag coefficients, with and without spray stress. These analyses illustrated downwelling ahead of every storm, legacy drag coefficients as statistical outliers, invalid for TC modeling, and although its addition reduced model accuracy, sea spray remains paramount through modern drag coefficient selection. The confirmation of downwelling is supported by Ekman dynamics and may be significant in storm surge enhancement.
NPS CIVINS (Civilian Institutions) Thesis documentApproved for public release; distribution is unlimited
Showing items related by title, author, creator and subject.
Markham, David Gregory (Monterey, California. Naval Postgraduate School, 1983-06);The purpose of this research was to develop a coupled sea ice-ocean model capable of simulating the upper ocean circulation features of the Marginal Ice Zone (MIZ) . A sea ice model using the Rossby-similarity method ...
Zafran, Robert (Monterey, California. Naval Postgraduate School, 1977-09);The NPS Spectroirradiometer (spectral irradiance meter) incorporates a rotating spectral wedge filter and was developed to measure the spatial distribution of downwelling underwater solar irradiance. Spectral irradiance ...
Hays, Kevin Austin Samuel; Ramp, Steven R. (Monterey, California. Naval Postgraduate School, 1993-03);Five hydrographic (CTD) and acoustic Doppler current profiler (ADCP) cruises were conducted in February, May, August and late October/early November, 1991 and February, 1992 near the Farallon Islands off of central ...