First global analysis of SEASAT scatterometer winds and potential for meteorological research

The first global wind fields from SEASAT-A scatterometer (SASS) data were produced. Fifteen days of record are available on tape, with unique wind directions indicated for each observation. The methodology of the production of this data set is described, as well as the testing of its validity. A number of displays of the data, on large and small scales, analyzed and gridded, are provided

A new parameterization of an empirical model for wind/ocean scatterometry

The power law form of the SEASAT A Scatterometer System (SASS) empirical backscatter-to-wind model function does not uniformly meet the instrument performance over the range 4 to 24 /ms. Analysis indicates that the horizontal polarization (H-Pol) and vertical polarization (V-Pol) components of the benchmark SASS1 model function yield self-consistent results only for a small mid-range of speeds at larger incidence angles, and for a somewhat larger range of speeds at smaller incidence angles. Comparison of SASS1 to in situ data over the Gulf of Alaska region further underscores the shortcomings of the power law form. Finally, a physically based empirical SASS model is proposed which corrects some of the deficiencies of power law models like SASS1. The new model allows the mutual determination of sea surface wind stress and wind speed in a consistent manner from SASS backscatter measurements

A Note on Frame Dragging

The measurement of spin effects in general relativity has recently taken centre stage with the successfully launched Gravity Probe B experiment coming toward an end, coupled with recently reported measurements using laser ranging. Many accounts of these experiments have been in terms of frame-dragging. We point out that this terminology has given rise to much confusion and that a better description is in terms of spin-orbit and spin-spin effects. In particular, we point out that the de Sitter precession (which has been mesured to a high accuracy) is also a frame-dragging effect and provides an accurate benchmark measurement of spin-orbit effects which GPB needs to emulate

Lunar Fluid Core and Solid-Body Tides

Variations in rotation and orientation of the Moon are sensitive to solid-body tidal dissipation, dissipation due to relative motion at the fluid-core/solid-mantle boundary, and tidal Love number k2 [1,2]. There is weaker sensitivity to flattening of the core-mantle boundary (CMB) [2-5] and fluid core moment of inertia [1]. Accurate Lunar Laser Ranging (LLR) measurements of the distance from observatories on the Earth to four retroreflector arrays on the Moon are sensitive to lunar rotation and orientation variations and tidal displacements. Past solutions using the LLR data have given results for dissipation due to solid-body tides and fluid core [1] plus Love number [1-5]. Detection of CMB flattening has been improving [3,5] and now seems significant. This strengthens the case for a fluid lunar core

What is in a pebble shape?

We propose to characterize the shapes of flat pebbles in terms of the statistical distribution of curvatures measured along the pebble contour. This is demonstrated for the erosion of clay pebbles in a controlled laboratory apparatus. Photographs at various stages of erosion are analyzed, and compared with two models. We find that the curvature distribution complements the usual measurement of aspect ratio, and connects naturally to erosion processes that are typically faster at protruding regions of high curvature.Comment: Phys. Rev. Lett. (to appear

The shape and erosion of pebbles

The shapes of flat pebbles may be characterized in terms of the statistical distribution of curvatures measured along their contours. We illustrate this new method for clay pebbles eroded in a controlled laboratory apparatus, and also for naturally-occurring rip-up clasts formed and eroded in the Mont St.-Michel bay. We find that the curvature distribution allows finer discrimination than traditional measures of aspect ratios. Furthermore, it connects to the microscopic action of erosion processes that are typically faster at protruding regions of high curvature. We discuss in detail how the curvature may be reliable deduced from digital photographs.Comment: 10 pages, 11 figure

Recoiling from a kick in the head-on collision of spinning black holes

Recoil ``kicks'' induced by gravitational radiation are expected in the inspiral and merger of black holes. Recently the numerical relativity community has begun to measure the significant kicks found when both unequal masses and spins are considered. Because understanding the cause and magnitude of each component of this kick may be complicated in inspiral simulations, we consider these effects in the context of a simple test problem. We study recoils from collisions of binaries with initially head-on trajectories, starting with the simplest case of equal masses with no spin and then adding spin and varying the mass ratio, both separately and jointly. We find spin-induced recoils to be significant relative to unequal-mass recoils even in head-on configurations. Additionally, it appears that the scaling of transverse kicks with spins is consistent with post-Newtonian theory, even though the kick is generated in the nonlinear merger interaction, where post-Newtonian theory should not apply. This suggests that a simple heuristic description might be effective in the estimation of spin-kicks.Comment: 12 pages, 10 figures. Replaced with published version, including more discussion of convergence and properties of final hol

Effects of Growth Pattern on Muscle Growth, Nuclei Number, Protein Accretion, and Body Composition in Heifers

The effects of compensatory growth on accretion of muscle mass, protein mass, and nuclei number of the supraspinatus and semitendinosus muscles were evaluated using seven serial slaughter groups of Angus x Limousin heifer calves (n = 28, BW 270 2 9.5 kg). Fractional growth rates of carcass protein and fat were also evaluated. To achieve compensatory growth, energy intake was restricted for 88 days (Phase 1) followed by adlibitum feeding of a high energy diet (Phase2) [LH]. Controls were allowed continuous ad libitum access to the high energy diet (HH). Muscle weights, body composition samples, and muscle biopsies were collected at various weight (465 vs 500 kg) or age (88 vs 186 days) constants. Phase 1 energy restriction limited body weight, carcass weight, carcass protein mass, and carcass fat mass (P\u3c.05). This was the result of the limited tissue fractional growth rates. The fractional growth rate of protein for heifers exhibiting compensatory growth was not increased but was maintained until maximum carcass protein mass was attained. Maximum carcass protein mass was attained by a weight of 465 kg. Any further increase in carcass weight was primarily attributed to an increase of carcass fat mass regardless of previous management. Energy restriction limited muscle, protein, and nuclei accretion rates. Heifers exhibiting compensatory growth sustained a linear growth potential until maximum muscle mass occurred at an end point similar to cattle not exhibiting compensatory growth. Muscle nuclei maintained a constant relationship to muscle mass independent of nutritional treatment, muscle type (supraspinatus vs semitendinosus), or days on feed. These data indicate compensatory growth alters the growth curve without affecting the mechanisms of growth

The Influence of Body Weight and Marbling EPD on the Relationship of Intramuscular Fat Content and the Value of Lean Retail Product in Serially Slaughtered Angus Steers

It is unclear how age, physiological maturity, and genetics affect intramuscular fat (IM) desposition in cattle. The study used beef cattle of known age and parentage to study the development of primal cuts, total carcass fat and IM fat depots as part of the growth process. Selecting cattle for marbling with the use of paternal grandsire\u27s EPD for marbling was not indicative of differences in the onset or the rate, of development of marbling. Greater differences in EPD for marbling may be needed to observe phenotypic differences. Harvest group affected the level and extent of marbling (P\u3c.10), however there was no harvest group x marbling group interactions indicating no differences occurred in the pattern of marbling development due to marbling EPD. Carcasses expressed a Small degree of marbling between the hot carcass weights of 550 and 650 Ibs. and at a back fat depth of approximately .30 in. In this study utilizing non-implanted steers of the same breed, we found that as days on feed increased, hot carcass weights, back fat depth, and percent carcass fat increased along with marbling score as well as percent 12th rib lipid content. No differences were observed in the weight of the primal cuts when expressed as a percentage of the chilled carcass between marbling groups at each of the five end points. As HCW increased across harvest groups, primal weight increased without a change in the percentage of the carcass represented by the middle meats (sirloin, shortloin, rib)

Effects of Energy Restriction and Realimentation on the Development of Carcass Traits of Yearling Heifers

Feedlot performance and carcass development were compared between heifers fed a low energy diet for an 88-day backgrounding period before receiving a high energy diet (LE) and heifers receiving a high energy diet throughout the trial (HE). The LE heifers were delayed in carcass and muscle growth (P\u3c.10) when compared to HE heifers on day 89. At an 1100 1b weight constant, LE and HE carcasses had similar dissected muscle weights, rib fat measurements and marbling scores. Carcass dressing percentage was only affected by time (P\u3c.10) on an energy dense diet at 1030 Ib. During the initial 88-day background period, HE heifers had higher ADG (P\u3c.001) and lower Feed/gain requirements (P\u3c.001). During realimentation, compensatory growth was exhibited through increased ADG (P\u3c .lo) and improved feed/gain (P\u3c.05) for LE heifers. From day 0 until slaughter, the cumulative ADG for HE heifers was greater (P\u3c.05) and the cumulative feed conversion was lower for HE heifers (P\u3c.10)