An estimate of bottom frictional dissipation by Gulf Stream fluctuations

Using published values of the kinetic energy per unit mass of fluctuating motions for the deep western North Atlantic an estimate is made of the energy dissipation rate from fluctuations by bottom friction for the Gulf Stream System. It appears that bottom friction may account for all the energy input by the wind, and that this dissipation occurs in only about 20% of the areal extent of this gyre

The relationship between structural game characteristics and gambling behavior: a population-level study

The aim of this study was to examine the relationship between the structural characteristics and gambling behavior among video lottery terminal (VLT) gamblers. The study was ecological valid, because the data consisted of actual gambling behavior registered in the participants natural gambling environment without intrusion by researchers. Online behavioral tracking data from Multix, an eight game video lottery terminal, were supplied by Norsk-Tipping (the state owned gambling company in Norway). The sample comprised the entire population of Multix gamblers (N = 31,109) who had gambled in January 2010. The individual number of bets made across games was defined as the dependent variable, reward characteristics of a game (i.e., payback percentage, hit frequency, size of winnings and size of jackpot) and bet characteristics of a game (i.e., range of betting options and availability of advanced betting options) served as the independent variables. Control variables were age and gender. Two separate cross-classified multilevel random intercepts models were used to analyze the relationship between bets made, reward characteristics and bet characteristics, where the number of bets was nested within both individuals and within games. The results show that the number of bets is positively associated with payback percentage, hit frequency, being female and age, and negatively associated with size of wins and range of available betting options. In summary, the results show that the reward characteristics and betting options explained 27 % and 15 % of the variance in the number of bets made, respectively. It is concluded that structural game characteristics affect gambling behavior. Implications of responsible gambling are discussed

A Numerical Study of the Interaction Between a Deep Cold Jet and the Bottom Boundary Layer of the Ocean

Abstract A two-dimensional (x-z) primitive equation model is used to study the interaction between a deep cold jet on a sloping bottom and the bottom boundary layer (BBL) of the deep ocean. Two closure schemes are used: a standard second order turbulence closure (SOTC) scheme (the level 2 1/2 model of Mellor and Yamada), and a new eddy viscosity closure scheme (K-model). The latter is a computationally simple model that produces very similar eddy viscosity and velocity fields as the more complicated SOTC-model while saving about 20% of the computational time. The results of the numerical simulations compare favorably to observations from the base of the North Atlantic continental rise where the cold jet known as the Cold Filament (CF) is found. The interaction between the CF and the BBL is found to be dominated by cross-isotherm Ekman flow, resulting in an asymmetry effect with different dynamics at each one of the fronts associated with the CF. Some of the unusual characteristics of this region are explained with the aid of the numerical experiments. These are: velocity profiles significantly different from those obtained by classical Ekman dynamics, unstable BBLs and detachment of bottom layers. Spatial variations in the characteristics of the BBL which are often neglected in deep-ocean studies are found to be significant in this region

Energetics of the Kuroshio south of Japan

Historical GEK data are used to estimate the flow of energy from the mean current to the fluctuations for the surface of the Kuroshio in a region south of Japan. The horizontal transfer components of kinetic energy and temperature variance are calculated and are found to be similar to estimates for the Florida Current...

Near bottom speed and temperature observations on the Blake-Bahama outer ridge

Speed and temperature measurement made in the bottom boundary layer (BBL) in the region of the Western Boundary Undercurrent at 28°22′N, 74° 13′W over an ∼11 day period are presented. The observations suggest that the BBL structure is consistent with that of a turbulent Ekman layer formed in an initially stably stratified fluid over a uniform surface even though they were obtained in and above an abyssal furrow. The inferred friction velocities u*(ū* = 0.66 cm/s) generally are larger than those inferred by Weatherly (1972) under the Florida Current and at times sufficiently large to result in erosion of some of the finer cohesive sediments if the criterion for their erosion summarized in McCave (1978) is assumed to apply at the site of the observations

Thursday

https://digitalcommons.library.umaine.edu/mmb-vp/6377/thumbnail.jp

Measurements of the atmospheric neutrino flux by Super-Kamiokande: energy spectra, geomagnetic effects, and solar modulation

A comprehensive study on the atmospheric neutrino flux in the energy region from sub-GeV up to several TeV using the Super-Kamiokande water Cherenkov detector is presented in this paper. The energy and azimuthal spectra of the atmospheric ${\nu}_e+{\bar{\nu}}_e$ and ${\nu}_{\mu}+{\bar{\nu}}_{\mu}$ fluxes are measured. The energy spectra are obtained using an iterative unfolding method by combining various event topologies with differing energy responses. The azimuthal spectra depending on energy and zenith angle, and their modulation by geomagnetic effects, are also studied. A predicted east-west asymmetry is observed in both the ${\nu}_e$ and ${\nu}_{\mu}$ samples at 8.0 {\sigma} and 6.0 {\sigma} significance, respectively, and an indication that the asymmetry dipole angle changes depending on the zenith angle was seen at the 2.2 {\sigma} level. The measured energy and azimuthal spectra are consistent with the current flux models within the estimated systematic uncertainties. A study of the long-term correlation between the atmospheric neutrino flux and the solar magnetic activity cycle is also performed, and a weak indication of a correlation was seen at the 1.1 {\sigma} level, using SK I-IV data spanning a 20 year period. For particularly strong solar activity periods known as Forbush decreases, no theoretical prediction is available, but a deviation below the typical neutrino event rate is seen at the 2.4 {\sigma} level.Comment: 30 pages, 31 figure

Too cold\u27 bottom layers at the base of the Scotian Rise

CTD data indicate that the bottom boundary layer in a region of the western North Atlantic near 40N 62W is a distinct body of relatively cold (θ \u3c 1.82°C), fresh (S \u3c 34.894‰) water. This region is a strip ~ 100 km wide aligned approximately along isobaths centered near the 4900 m isobath on the continental margin near its base...