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Øyvind Saetra, Jon Albretsen, and Peter A. E. M. Janssen

condition in both the atmospheric and the ocean models, the net momentum flux is not necessarily conserved. The amount of momentum lost from the atmosphere may be different from the amount of momentum gained by the ocean. A second point is that the surface stress is also, to a large extent, dependent on the sea state, that is, how the wave energy is distributed over the frequency range. A young wind sea is more dominated by waves in the high-frequency part of the spectrum than an old wind sea, whereas

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James Foster, Ning Li, and Kwok Fai Cheung

1. Introduction Direct measurements of sea state are mostly performed by wave buoys or from sensors attached to fixed structures such as drilling platforms. While buoys provide accurate observations, the high costs for initial installation, and ongoing maintenance and communications have tended to limit their deployment to coastal waters, augmented by a sparse deep-water network ( Fig. 1 ). Global coverage of sea state measurements can be provided by satellite observations (e.g., Gonzalez et

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James A. Mueller and Fabrice Veron

1. Introduction Current hurricane models are unable to produce high wind speeds when using traditional air–sea flux parameterizations. Emanuel (1995) showed that the ratio of the enthalpy exchange coefficient to the drag coefficient controls the maximum wind speed and that traditional parameterizations produce too low of a ratio when extrapolated to high wind speeds. Consequently, some combination of a higher enthalpy exchange coefficient and a lower drag coefficient is necessary to simulate

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R. S. Gibson, C. Swan, and P. S. Tromans

order to have confidence in the extremes of the distributions, many hours of a particular sea state must be modeled. Many of these limitations can be overcome by using the SRS method. First, by incorporating a suitable wave model into the method, the full nonlinearity can be considered. This task is addressed in the present paper. Second, the sea state can be described by a realistic broadbanded and directionally spread spectrum; the former is addressed herein, and the latter is left for a

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Paul A. Hwang, Héctor García-Nava, and Francisco J. Ocampo-Torres

illustrate the temporal variation. A star indicates the starting condition, a triangle represents the condition at the maximal wind speed that separates the growing and decaying phases of the event, and a circle denotes the end of the event. Because of the mixed-sea condition, the starting state (indicated by the star) may deviate considerably from the more ideal fetch-limited growth curves. As the wind event begins, the wind sea quickly adjusts to the condition similar to that of the ideal fetch

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Duncan Cook and Sally Garrett

the Horn of Africa was conducted in sea states of 4 and below (94% of paired observations) ( Fig. 7 ), with most of these attacks launched in relatively calm oceans of sea state 3 and below (wave heights < 1.25 m). Attack success steadily declined as wave heights increased, with threshold behavior less conspicuous than that exhibited by the wind speed results ( Fig. 7 ). Fig . 5. Location of pirate attacks (open circles) and matching satellite observations ( n = 155) used in this study. Black

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Paul A. Hwang and Yalin Fan

footing because of the advancing wind field and differences in the base sea state from upstream feeding. To account for the observed systematic deviation from the reference growth curves of the hurricane wind waves in different sectors ( Fig. 2 ), the fetches or durations for H s and T p are allowed to be different. The results show that the effective fetch and duration increase about linearly with the distance r to the measurement location from the hurricane center. The slope s and intercept

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Abushet W. Simanesew, Harald E. Krogstad, Karsten Trulsen, and José Carlos Nieto Borge

distribution of a typical unimodal sea state based on various analysis methods. For the directional spectra, shown in the upper row, there is only a minor difference among the methods, all showing clear unimodality, which is also reflected in the directional distributions shown in the lower row. Multimodality is a persistent feature in the Ekofisk data, where a large fraction of the directional spectra have evidence of bimodality for distributions above the spectral peak. Figure 10 shows occurrences of

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Richard D. Ray and Chester J. Koblinsky

JUNE I991 RICHARD D. RAY AND CHESTER J. KOBLINSKY 397On the Sea-State Bias of the Geosat Altimeter RICHARD D. RAYST Systems Corporation, Goddard Space Flight Center, Greenbelt, Maryland CHESTER J. KOBLINSKYSpace Geodesy Branch, NASA Goddard Space Flight Center, Greenbelt, Maryland(Manuscript received 5 April 1990, in final form 20 November 1990)ABSTRACT The sea-state bias in a satellite altimeter's range measurement

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Roman E. Glazman and Meric A. Srokosz

VOLUME21 JOURNAL OF PHYSICAL OCEANOGRAPHY NOVEMBER 1991Equilibrium Wave Spectrum and Sea State Bias in Satellite Altimetry ROMAN E. GLAZMANJet Propulsion Laboratory, California Institute of Technology, Pasadena, California MERIC A. SROKOSZRSADU, Institute of Oceanographic Sciences Deacon Laboratory, Wormley, Surrey, England(Manuscript received 23 October 1990, in final form 1 April 1991) ABSTRACT

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