Computer model of wind, waves, and longshore currents during a coastal storm

A mathematical model has been developed to forecast or hindcast wind, waves, and longshore currents during the passage of a coastal storm. Storm intensity is a function of the barometric pressure gradient which is modeled by rotating an inverted normal curve around the center of an ellipse. The length and orientation of the major and minor axes of the ellipse control the size and shape of the storm. The path of the storm is determined by a sequence of storm positions for the hindcast mode, and by interpolated positions assuming constant speed and direction for the forecast mode. The site location, shoreline orientation, and nearshore bottom slope provide input data for the shore position. The geostrophic wind speed and direction at the shore site are computed from the latitude and barometric pressure gradient. The geostrophic wind is converted into surface wind speed and direction by applying corrections for frictional effects over land and sea. The surface wind speed and direction, effective fetch, and wind duration are used to compute wave period, breaker height, and breaker angle at the shore site. The longshore current velocity is computed as a function of wave period, breaker height and angle, and nearshore slope. The model was tested by comparing observed data for several coastal locations with predicted values for wind speed, wave period and height, and longshore current velocity. Forecasts were made for actual storms and for hypothetical circular and elliptical storms.     

Starspot modelling of the RS CVn binary HK lacertae

Investigating more than 270 nightly mean magnitudes of the long-period RS CVn binary HK Lac, we can draw some conclusions about the nature of its complicated light variations. The mean brightness, the apparent photometric period, and the shape of the light curve all show strong variations. Analysis with a starspot model, assuming two large spots and a general uniform spottedness, indicates two comparably large spots which appear to have maintained their separate identities for the last 15 yr and drifted in longitude separation from each other smoothly by only about 45°. The phase of the two spots indicates both are rotating very nearly synchronously with the orbital motion, one slightly (0.025%) faster and the other slightly (0.080%) slower. the latitudes of the two spots, one farther above the equator and one closer to the equator, are consistent with solar-type differential rotation and yield an estimate of 25±12° for the co-rotating latitude. A correlation between mean spot latitude and instantaneous photometric period yields another estimate of 31±2°, in agreement with the first.     

The Application of Conditional Beta Density Functions to Model Time- Delay Measurement Errors

A conditional beta probability density function is employed to model time-delay measurement errors associated with sensors used in triangulation ranging applications. This type of density function is less restrictive than the beta density used in previous analyses in that end points can be extended out beyond the imposed range constraints and data editing is allowed before range calculations. The resulting conditional range density function is computed along with the mean and variance. Comparisons are made of the pertinent range statistics associated with the beta and conditional beta density functions. Finally, the conditional beta density function range statistics are compared with those obtained from a gated Gaussian density function for equivalent values of time-delay measurement error standard deviation. The Gaussian statistics are determined via Monte-Carlo simulation.     

The channel shape—grain size relation in eastern Australia and some paleohydrologic implications

The relation F = 255 M^?1.08 does not hold for clay-bedded streams in the Namoi—Gwydir distributary system of eastern Australia. Of the streams studied, only those with mobile beds conform to the relation. The application of the relation in paleohydrologic studies must include investigations of the nature of the paleochannels.     

Lateral dynamic analysis and classification of barotropic tidal inlets

The dynamical balances at shallow tidal inlets are highly nonlinear, and can vary substantially over sub-kilometer scales. In this study, barotropic dynamics are examined with numerical experiments on a series of idealized inlets with differing inlet widths and lengths. Circulation and elevation fields obtained from fully nonlinear depth-integrated circulation models are used to reconstruct the contribution of each term in the momentum equations. Momentum terms are rotated into a streamline coordinate system to simplify interpretation of the dynamics. Spatial patterns in momentum reveal that the lateral balances at inlets can vary from nearly geostrophic to strongly cyclostrophic. Marked dynamical differences are seen between inlets with different lengths and widths. Inlet regions of geostrophic or cyclostrophic balances can be predicted using two dimensionless parameters, the dynamic length L^* and dynamic width W^*. A classification scheme is proposed using L^* and W^* to compare the idealized inlets analyzed here with inlets from 20 previous studies. Four distinct inlet types are identified and discussed.     

Residential preferences in the city of Warsaw,Poland

Warsaw was heavily damaged during World War II. Post-War socialist reconstruction emphasized public multi-family housing. A 1987 survey revealed that about one-third of Warsaw residents lived in single-family units, though most expressed their preferences to live in single family houses free from noise pollution and in an aesthetically acceptable environment. In two areas, the CBD and the Praga North, a large proportion of residents preferred to live in existing multi-family units, though such preference was much greater among the blue collar workers than white collar.     

Acute toxicity of the water-soluble fraction of Cook Inlet crude oil to the Manila clam

Recognition of the inherent complexities of oil bioassays prompted the development of several apparatuses designed to deliver uniform solutions of the water-soluble components of crude oil and capable of system equilibration for both static and continuous-flow bioassays without the loss of the more volatile compounds and without the formation of emulsions. Clams from a relatively contaminated area exhibited greater resistance to the water-soluble fraction of Cook Inlet crude oil than specimens from a more pristine area. Behaviour was altered below lethal levels suggesting the possibility of using behavioural modifications as a concommitant criterion of toxicity with mortality. An increase in mortality with a longer exposure period and a significant rate of latent mortalities following the end of the 96-h exposure period suggest that future bioassays with bivalves should be determined over a longer exposure period.     

Rare earth elements in carbonatite and cogenetic alkaline rocks: Examples from Seabrook Lake and Callander Bay,Ontario

Associated rocks from the Seabrook Lake, carbonatite complex in Ontario show an increase in total REE (rare earth element) content and in light REE enrichment in the following order: fenite quartz monzohite 2 and H₂O-rich fluids.