Meteorology Commons^™

Analytic Forms Of Bidirectional Reflectance Functions For Application To Earth Radiation Budget Studies, N. Manalo-Smith, G. L. Smith, S. N. Tiwari, W. F. Staylor

Mechanical & Aerospace Engineering Faculty Publications

Analytic expressions for the bidirectional reflectance functions are formulated and fit to the Earth Radiation Budget Experiment (ERBE) operational models, which were developed using Nimbus 7 ERB data. The analytic bidirectional reflectance distribution functions (BRDFs) are based on theoretical considerations and are functions of viewing geometry and scene type. The models consist of a Rayleigh scattering term and a term for scattering due to clouds and surface. The darkness of the ocean permits the empirical determination of the Rayleigh component of scattering from the atmosphere. The models have the advantage that they are smooth in terms of view and solar …

Studies Of Warm-Core Rings Using A Particle-In-Cell Method, John James Holdzkom Ii

OES Theses and Dissertations

A particle-in-cell (PIC) model is developed and applied to problems involving the evolution of warm-core rings. Such models are a hybrid of conventional Eulerian and Lagrangian models. They are ideally suited for problems in which a lower layer outcrops to the surface, such as at the boundary of a ring.

The model is developed in three implementations. First, for purposes of model validation, a reduced gravity model is described. The PIC model reproduces the essential characteristics of analytical solutions to the reduced gravity equations and integral invariants are conserved to a high degree. Next, a 1.5-layer model is developed and …

Data Assimilation Experiments In The Gulf Stream Region: How Useful Are Satellite-Derived Surface Data For Nowcasting The Subsurface Fields?, Tal Ezer, George L. Mellor

CCPO Publications

Satellite-derived surface data have become an important source of information for studies of the Gulf Stream system. The question of just how useful these datasets are for nowcasting the subsurface thermal fields, however, remains to be fully explored. Three types of surface data-sea surface temperature (SST), sea surface height (SSH), and Gulf Stream position (GSP)-are used here in a series of data assimilation experiments to test their usefulness when assimilated into a realistic primitive equation model. The U.S. Navy's analysis fields from the Optimal Thermal Interpolation System are used to simulate the surface data and to evaluate nowcast errors. Correlation …

Continuous Assimilation Of Geosat Altimeter Data Into A Three-Dimensional Primitive Equation Gulf Stream Model, Tal Ezer, George L. Mellor

CCPO Publications

A three-dimensional data assimilation scheme is described and tested, using the Geosat altimeter data and a high-resolution, primitive equation, numerical ocean model of the Gulf Stream region. The assimilation scheme is based on an optimal interpolation approach in which data along satellite tracks are continuously interpolated horizontally and vertically into the model grid and assimilated with the model prognostic fields. Preprocessed correlations between surface elevation anomalies and subsurface temperature and salinity anomalies are used to project surface information into the deep ocean; model and data error estimates are used to optimize the assimilation. Analysis fields derived from the Navy's Optimum …

A Numerical Study Of The Variability And The Separation Of The Gulf Stream, Induced By Surface Atmospheric Forcing And Lateral Boundary Flows, Tal Ezer, George L. Mellor

CCPO Publications

A primitive equation model is used to study the effects of surface and lateral forcing on the variability and the climatology of the Gulf Stream system. The model is an eddy-resolving, coastal ocean model that includes thermohaline dynamics and a second-order turbulence closure scheme to provide vertical mixing. The surface forcing consists of wind stress and heat fluxes obtained from the Comprehensive Ocean-Atmosphere Data Set (COADS). Sensitivity studies are performed by driving the model with different forcing (e.g., annual versus zero surface forcing or monthly versus annual forcing). The model climatology, obtained from a five-year simulation of each case, is …

The Effect On Earth's Surface-Temperature From Variations In Rotations Rate, Continent Formation, Solar Luminosity, And Carbon Dioxide, William R. Kuhn, J. C.G. Walker, Harold G. Marshall

Biological Sciences Faculty Publications

Proposed evolutionary histories of solar luminosity, atmospheric carbon dioxide amounts, Earth rotation rate, and continent formation have been used to generate a time evolution of Earth's surface temperature. While speculative because of uncertainties in the input parameters, such a study does help to prioritize the areas of most concern to paleoclimatic research while illustrating the relationships and mutual dependencies. The mean temperature averages about 5 K higher than today over most of geologic time; the overall variation is less than 15 K. The evolution of Earth's rotation rate makes a significant contribution to the surface temperature distribution as late as …

Storm Surge Predictions At Sewell's Point With Local Wind, Pressure, And Previous Surge As Surge Predictors In Chesapeake Bay, Joy Elaine Moses

OES Theses and Dissertations

The statistical model used to predict storm surge. which is defined as the difference between observed water level and predicted astronomical tide. at Sewell's Point. Virginia. for the last ten years relies on forecast surface air pressures interpolated over a large portion of the Atlantic Ocean. A variation on this method is developed which adds previous station surge and local wind and pressure terms with time leads up to 18 hours to the Pore prediction for surge. and develops surge prediction equations for three substations eight to 65 miles (13 to 105 km) from Sewell's Point. The Sewell's Point surge …

Investigation Of Eddy Population And Motion In The Southern International Ice Patrol Operations Area (40°-47°N By 40°-55°W), Frank J. Williams

OES Theses and Dissertations

A study of the eddy population in the Newfoundland Basin region over the period from November 1981 to December 1984 was conducted. The study was undertaken to demonstrate the importance and basic character of eddy motion in the area patrolled by the International Ice Patrol. This is a descriptive study and no rigorous mathematical solutions are attempted. Data was collected on the number of eddies in the area, their average duration and size, formation, migration and deterioration patterns and rotational velocity. Satellite infrared imagery maintained by National Weather Service and Naval Eastern Oceanographic Center, Canadian Forces METOC Center sea surface …

Effects Of El Nino On Local Hydrography And Growth Of The Giant Kelp, Macrocystis Pyrifera, At Santa Catalina Island, California, Richard C. Zimmerman, Deborah L. Robertson

OES Faculty Publications

Deepened isotherms associated with El Niño resulted in severe nutrient limitation and very low kelp productivity during the last half of 1983. Frond growth rates were so low that terminal blades formed before reaching the surface, eliminating the canopy. Frond initiation rates were also extremely low, resulting in significant reductions in mean plant size. Plants growing above 10m were more severely affected than plants at 20m. Nutrient pulses associated with internal waves are thus critical for survival of Macrocystis pyrifera in nutritionally marginal habitats in Southern California.

Variability Of Atmospheric Hydrocarbon Concentrations And Deposition Rates, Charles Thomas Farmer

OES Theses and Dissertations

The atmospheric hydrocarbon concentration was determined at various locations throughout Southeastern Virginia from July 1981 to February 1983. During this period the concentration ranged from 0.4 to 5.5 μg/m³ . From October 1982 to February 1983, WET and dry deposition samples were collected in conjunction with these air samples. Total hydrocarbon dry deposition rates ranged from deposition rates ranged from 4 to 189 μg/m² /day, while WET 22 to 670 μg/m² /day. Hydrocarbon concentrations found were within the ranges reported in the literature for wet, dry and atmospheric hydrocarbon concentrations.

Linear trend analysis revealed no correlation between …

Numerical Model Simulation Of Offshore Flow During The Winter Season, Maria Cintia Piccolo

OES Theses and Dissertations

Because of the step function variability of heat and moisture flux in coastal zones, adequate descriptive models of mesoscale coastal circulation and weather patterns demand high spatial resolution in the analysis of wind, temperature and moisture patterns. To obtain realistic concepts of offshore flow the sparse offshore data networks need to be supplemented by mesoscale numerical models. The problems associated with the modeling of offshore flow across the east coast of the United States during the winter season have been investigated with a simple two dimensional numerical model of the planetary boundary layer.

The model has two predictive equations for …