4,020 research outputs found

    Skylab S193 and the analysis of the wind field over the ocean

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    The present status of the program to provide proof of concept for the idea that simultaneously observed radar scattering cross section measurements and passive microwave measurements can be used to determine the winds in the planetary boundary layer over the ocean, is given. The role of S193 in Skylab is providing the final clinching proof that an operational instrument will obtain data of great value to both meteorology and oceanography is described

    Dynamic scaling of I-V data for the neutral 2D Coulomb gas

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    The value of the dynamic critical exponent z has been studied for experimental two-dimensional superconducting and Josephson Junction array systems in zero magnetic field via the Fisher-Fisher-Huse dynamic scaling analysis. We found z~5.6, a relatively large value indicative of non-diffusive dynamics. We extend this work here to simulational I-V curves that are also found to be characterized by the same large value of z.Comment: 2 pages, 2 embedded figures, LT22 proceedings, Physica

    Channel-wall limitations in the magnetohydrodynamic induction generator

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    Discussion of magnetohydrodynamic induction generator examines the machine in detail and materials problems influencing its design. The higher upper-temperature limit of the MHD system promises to be more efficient than present turbine systems for generating electricity

    Flux Lattice Melting and the onset of H_c2 fluctuations

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    The flux lattice melting temperature in optimally doped YBCO has been shown to be very close to that of the onset of fluctuations around H_{c2}(T). Here, we present a theoretical argument in support of the idea that this occurs because the increased strength of the fluctuations as a function of magnetic field pushes away the first order flux lattice melting transition. The argument is based on hydrodynamic considerations (the Hansen-Verlet freezing criterion). It is not specific to high-temperature superconductors and can be generalized to other systems.Comment: 2 pages, 1 embedded figure, LT22 proceedings, Physica

    The extrapolation of laboratory and aircraft radar sea return data to spacecraft altitudes

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    Laboratory measurements show that the spectra of capillary waves grow with wind speed over six orders of magnitude. The scatter in the data can be partially understood and predicted from a combination of turbulence theory, radar theory, and the small sample theory of statistical inference. When these results are applied to a prediction of the sea return values to be obtained by S193 on Skylab, it can be shown that the size of the illuminated patch effectively averages out the horizontal scales of gustiness, so that the measurement will correspond to the synoptic scale wind

    Verification results for the Spectral Ocean Wave Model (SOWM) by means of significant wave height measurements made by the GEOS-3 spacecraft

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    Significant wave heights estimated from the shape of the return pulse wave form of the altimeter on GEOS-3 for forty-four orbit segments obtained during 1975 and 1976 are compared with the significant wave heights specified by the spectral ocean wave model (SOWM), which is the presently operational numerical wave forecasting model at the Fleet Numerical Weather Central. Except for a number of orbit segments with poor agreement and larger errors, the SOWM specifications tended to be biased from 0.5 to 1.0 meters too low and to have RMS errors of 1.0 to 1.4 meters. The much fewer larger errors can be attributed to poor wind data for some parts of the Northern Hemisphere oceans. The bias can be attributed to the somewhat too light winds used to generate the waves in the model. Other sources of error are identified in the equatorial and trade wind areas
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