3,299 research outputs found
Skylab S193 and the analysis of the wind field over the ocean
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
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
Oceanographic and meteorological research based on the data products of SEASAT
Reservations were expressed concerning the sum of squares wind recovery algorithm and the power law model function. The SAS sum of squares (SOS) method for recovering winds from backscatter data leads to inconsistent results when V pol and H pol winds are compared. A model function that does not use a power law and that accounts for sea surface temperature is needed and is under study both theoretically and by means of the SASS mode 4 data. Aspects of the determination of winds by means of scatterometry and of the utilization of vector wind data for meteorological forecasts are elaborated. The operational aspect of an intermittent assimilation scheme currently utilized for the specification of the initial value field is considered with focus on quantifying the absolute 12-hour linear displacement error of the movement of low centers
Channel-wall limitations in the magnetohydrodynamic induction generator
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
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
Does the scatterometer see wind speed or friction velocity?
Studies of radar backscatter from the sea surface are referred either to the wind speed, U, or friction velocity, u(sub *). Bragg scattering theory suggests that these variations in backscatter are directly related to the height of the capillary-gravity waves modulated by the larger waves in tilt and by straining of the short wave field. The question then arises as to what characteristic of the wind field is most probably correlated with the wave number spectrum of the capillary-gravity waves. The justification for selecting U as the appropriate meteorological parameter to be associated with backscatter from L-band to Ku-band are reviewed. Both theoretical reasons and experimental evidence are used to demonstrate that the dominant parameter is U/C(lambda) where U is the wind speed at a height of about lambda/2 for waves having a phase speed of C(lambda)
Vector wind, horizontal divergence, wind stress and wind stress curl from SEASAT-SASS at one degree resolution
Conventional data obtained in 1983 are contrasted with SEASAT-A scatterometer and scanning multichannel microwave radiometer (SMMR) data to show how observations at a single station can be extended to an area of about 150,000 square km by means of remotely sensed data obtained in nine minutes. Superobservations at a one degree resolution for the vector winds were estimated along with their standard deviations. From these superobservations, the horizontal divergence, vector wind stress, and the curl of the wind stress can be found. Weather forecasting theory is discussed and meteorological charts of the North Pacific Ocean are presented. Synoptic meteorology as a technique is examined
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