Relevant bibliographies by topics / Winds Antarctica Mathematical models

Academic literature on the topic 'Winds Antarctica Mathematical models'

Author: Grafiati
Published: 10 December 2022
Last updated: 29 January 2023

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Contents

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Winds Antarctica Mathematical models.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Winds Antarctica Mathematical models"

1

Albert, Mary R., Edward F. Shultz, and Frank E. Perron. "Snow and firn permeability at Siple Dome, Antarctica." Annals of Glaciology 31 (2000): 353–56. http://dx.doi.org/10.3189/172756400781820273.

Full text
Abstract:
AbstractThe nature of air-snow exchange processes depends upon both the physical characteristics of the snow and forcing from the atmosphere. An understanding of snow-air transport processes and models of these processes are important for interpreting ice cores and for predicting remotely sensed snow-surface characteristics. Accurate modeling requires knowledge of the physical characteristics of the snow and firn. In this paper, measurements of snow and firn permeability from the surface down to 12 m depth at Siple Dome, Antarctica, are presented. The permeability varies greatly as a function of layer and depth, generally increasing to approximately 3 m, and generally decreasing below that. The maximum permeability,280 × 10–10 1 0 m2, occurs at approximately 3 m depth. The lowest permeability in the top 12 m of snow and firn, 10 × 10–10w m2, was measured in the surface wind pack/The measurements show that layering and microstructure have large effects on permeability A mathematical expression for the overall variation of permeability with depth is presented It is shown that snow density is a poor indicator of permeability Quantitative microscopy may be helpful in relating observed snow characteristics to permeability, and useful in modeling firnification and chemical-species transport.
APA, Harvard, Vancouver, ISO, and other styles
2

Zuo, Guangyu, Yinke Dou, Xiaomin Chang, and Yan Chen. "Design and Application of a Standalone Hybrid Wind–Solar System for Automatic Observation Systems Used in the Polar Region." Applied Sciences 8, no. 12 (November 24, 2018): 2376. http://dx.doi.org/10.3390/app8122376.

Full text
Abstract:
Continuous power supply for unmanned and automatic observation systems without suitable energy-storage capabilities in the polar regions is an urgent problem and challenge. However, few power-supply systems can stably operate over the long term in extreme environments, despite excellent performance under normal environments. In this study, a standalone hybrid wind–solar system is proposed, based on operation analysis of the observing system in the Arctic Ocean, the polar environments, and renewable-energy distribution in the polar regions. Energy-storage technology suitable for cold regions is introduced to support the standalone hybrid wind–solar system. Mathematical models of the power system at low temperature are also proposed. The low-temperature performance and characteristics of lead–acid battery are comprehensively elucidated, and a dedicated charging strategy is developed. A hybrid wind–solar charging circuit is developed using a solar charging circuit, a wind turbine charging circuit, a driver circuit, a detection circuit, an analog-to-digital converter (ADC) circuit, and an auxiliary circuit. The low temperature stability of charging circuit is test from −50 °C to 30 °C. Temperature correction algorithm is designed to improve the efficiency of the power supply system. The power generation energy of the power system was simulated based on the monthly average renewable energy data of Zhongshan Station. A case study was applied to examine the technical feasibility of the power system in Antarctica. The five-month application results indicate that the power system based on renewable energy can maintain stable performance and provide sufficient power for the observing system in low ambient temperatures. Therefore, this power system is an ideal solution to achieve an environmentally friendly and reliable energy supply in the polar regions.
APA, Harvard, Vancouver, ISO, and other styles
3

Chen, Jiqing, Shaorong Xie, Jun Luo, and Hengyu Li. "Wind-driven land-yacht robot mathematical modeling and verification." Industrial Robot: An International Journal 43, no. 1 (January 18, 2016): 77–90. http://dx.doi.org/10.1108/ir-03-2015-0052.

Full text
Abstract:
Purpose – The purpose of this paper was to solve the shortage of carrying energy in probing robot and make full use of wind resources in the Antarctic expedition by designing a four-wheel land-yacht. Land-yacht is a new kind of mobile robot powered by the wind using a sail. The mathematical model and trajectory of the land-yacht are presented in this paper. Design/methodology/approach – The mechanism analysis method and experimental modeling method are used to establish a dual-input and dual-output mathematical model for the motion of land-yacht. First, the land-yacht’s model structure is obtained by using mechanism analysis. Then, the models of steering gear, servomotors and force of wing sail are analyzed and validated. Finally, the motion of land-yacht is simulated according to the mathematical model. Findings – The mathematical model is used to analyze linear motion and steering motion. Compared with the simulation results and the actual experimental tests, the feasibility and reliability of the proposed land-yacht modeling are verified. It can travel according to the given signal. Practical implications – This land-yacht can be used in the Antarctic, outer planet or for harsh environment exploration. Originality/value – A land-yacht is designed, and the contribution of this research is the development of a mathematical model for land-yacht robot. It provides a theoretical basis for analysis of the land-yacht’s motion.
APA, Harvard, Vancouver, ISO, and other styles
4

Zhekov, Svetozar A., A. V. Myasnikov, and N. A. Belov. "Radiative colliding winds models: the stagnation point singularity." Symposium - International Astronomical Union 193 (1999): 402. http://dx.doi.org/10.1017/s0074180900205949.

Full text
Abstract:
The singularity at the stagnation point in steady-state colliding winds has a big influence on the structure of the radiative interaction region. None of the existing numerical models treats properly this mathematical problem. As a result, all the available models cannot be used for deriving the stellar winds parameters by making a comparison with the observed X-ray properties.
APA, Harvard, Vancouver, ISO, and other styles
5

Belova, Evgenia, Peter Voelger, Sheila Kirkwood, Susanna Hagelin, Magnus Lindskog, Heiner Körnich, Sourav Chatterjee, and Karathazhiyath Satheesan. "Validation of wind measurements of two mesosphere–stratosphere–troposphere radars in northern Sweden and in Antarctica." Atmospheric Measurement Techniques 14, no. 4 (April 12, 2021): 2813–25. http://dx.doi.org/10.5194/amt-14-2813-2021.

Full text
Abstract:
Abstract. Two atmospheric VHF radars: ESRAD (Esrange MST radar) located near Kiruna in the Swedish Arctic and MARA (Moveable Atmospheric Radar for Antarctica) at the Indian research station Maitri in Antarctica perform wind measurements in the troposphere and lower stratosphere on a regular basis. We compared horizontal winds at altitudes between about 0.5 and 14 km derived from the radar data using the full correlation analysis (FCA) technique with radiosonde observations and models. The comparison with 28 radiosondes launched from January 2017 to August 2019 showed that ESRAD underestimates the zonal and meridional winds by about 8 % and 25 %, respectively. This is likely caused by the receiver group arrangement used for the FCA together with a high level of non-white noise. A similar result was found when comparing with the regional numerical weather prediction model HARMONIE-AROME (Bengtsson et al., 2017) for the period September 2018–May 2019. The MARA winds were compared with winds from radiosondes for the period February–October 2014 (291 occasions). In contrast to ESRAD, there is no indication that MARA underestimates the winds compared to the sondes. The mean difference between the radar and radiosonde winds is close to zero for both zonal and meridional components. The comparison of MARA with the ECMWF ERA5 reanalysis for January–December 2019 reveals good agreement with the mean difference between 0.1 and −0.5 m/s depending on the component and season. The random errors in the wind components (standard deviations over all estimates in 1 h averages) are typically 2–3 m/s for both radars. Standard deviation of the differences between radars and sondes are 3–5 m/s.
APA, Harvard, Vancouver, ISO, and other styles
6

Zika, Jan D., Julien Le Sommer, Carolina O. Dufour, Alberto Naveira-Garabato, and Adam Blaker. "Acceleration of the Antarctic Circumpolar Current by Wind Stress along the Coast of Antarctica." Journal of Physical Oceanography 43, no. 12 (December 1, 2013): 2772–84. http://dx.doi.org/10.1175/jpo-d-13-091.1.

Full text
Abstract:
Abstract The influence of wind forcing on variability of the Antarctic Circumpolar Current (ACC) is investigated using a series of eddy-permitting ocean–sea ice models. At interannual and decadal time scales the ACC transport is sensitive to both the mean strength of westerly winds along the ACC circumpolar path, consistent with zonal momentum balance theories, and sensitive to the wind stresses along the coast of Antarctica, consistent with the “free mode” theory of Hughes et al. A linear combination of the two factors explains differences in ACC transport across 11 regional quasi-equilibrium experiments. Repeated single-year global experiments show that the ACC can be robustly accelerated by both processes. Across an ensemble of simulations with realistic forcing over the second half of the twentieth century, interannual ACC transport variability owing to the free-mode mechanism exceeds that due to the zonal momentum balance mechanism by a factor of between 3.5 and 5 to one. While the ACC transport may not accelerate significantly owing to projected increases in along-ACC winds in future decades, significant changes in transport could still occur because of changes in the stress along the coast of Antarctica.
APA, Harvard, Vancouver, ISO, and other styles
7

Spencer, S. J., and L. E. Cram. "Magnetic Field Generation by Galactic Winds." Symposium - International Astronomical Union 157 (1993): 357–65. http://dx.doi.org/10.1017/s007418090017442x.

Full text
Abstract:
A new mechanism is presented for the local amplification and possible global dynamo maintenance of non-axisymmetric large-scale magnetic fields in disk galaxies. Shear in a galactic wind or large-scale flow of ionised gas with components axial and radial to the disk plane may regenerate large-scale magnetic fields.Numerical results are presented from kinematic mathematical models based on a local (thin disk) approximation and an exact three-dimensional formulation. The one-dimensional thin-disk model illustrates the possibility of exponential amplification and the resulting local axial spatial structure of large-scale galactic magnetic fields. Three-dimensional results support the possibility of global wind dynamo action.
APA, Harvard, Vancouver, ISO, and other styles
8

Nishimura, Kouichi, and Masaki Nemoto. "Blowing snow at Mizuho station, Antarctica." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 363, no. 1832 (July 2005): 1647–62. http://dx.doi.org/10.1098/rsta.2005.1599.

Full text
Abstract:
Blowing snow observations were carried out at Mizuho station, Antarctica, from October to November 2000. A blowing snow observation system including snow particle counters, which can sense not only the number of snow particles, but also their diameters, was situated on a 30 m tower. All instruments worked correctly and the data obtained revealed profiles of mass flux and particle size distributions as a function of the friction velocity. Measurements were compared with a blowing snow model that accounted for most physical processes including aerodynamic entrainment, grain/bed collisions, wind modification, particle size distribution and turbulent fluctuations on the particle trajectories. Simulated and measured results showed close agreement, and the validity of the model was demonstrated. Vertical profiles of horizontal mass flux from saltation to suspension, as well as the particle size distributions were expressed precisely, which could not be achieved using the previous models.
APA, Harvard, Vancouver, ISO, and other styles
9

Van Den Broeke, Michiel, and Richard Bintanja. "The interaction of katabatic winds and the formation of blue-ice areas in East Antarctica." Journal of Glaciology 41, no. 138 (1995): 395–407. http://dx.doi.org/10.1017/s0022143000016269.

Full text
Abstract:
AbstractBlue-ice areas (BIAs) are an extreme example of a local mass-balance gradient and are furthermore reasonably stable in time and space owing to local feed-back mechanisms. A meteorological experiment, performed in and around a blue-ice area in Dronning Maud Land. East Antarctica, showed that during drifting-snow conditions surface wind speed over the blue ice behind the mountain barrier is equal to that away from the mountains, when corrected for surface roughness and stability. This implies that use of diagnostic katabatic wind models to estimate divergence of drifting snow can be extended to the situation where nunataks are involved in preventing the drifting snow from passing, which is the case for most BIAs. A diagnostic model is tested for a two-dimensional profile in Terre Adélie. after which it is applied to entire East Antarctica. The present order-of-magnitude estimate shows that areas sensitive to blue-ice formation appear where precipitation is low and mean annual wind speed is high, i.e. in Dronning Maud Land and the drainage basin of Lambert Glacier. The results appeared to be especially sensitive to a change in inversion strength: a decrease in inversion strength weakens the katabatic flow, and thus the amount of snowdrift transport, reducing the area where BIAs can develop.
APA, Harvard, Vancouver, ISO, and other styles
10

Van Den Broeke, Michiel, and Richard Bintanja. "The interaction of katabatic winds and the formation of blue-ice areas in East Antarctica." Journal of Glaciology 41, no. 138 (1995): 395–407. http://dx.doi.org/10.3189/s0022143000016269.

Full text
Abstract:
AbstractBlue-ice areas (BIAs) are an extreme example of a local mass-balance gradient and are furthermore reasonably stable in time and space owing to local feed-back mechanisms. A meteorological experiment, performed in and around a blue-ice area in Dronning Maud Land. East Antarctica, showed that during drifting-snow conditions surface wind speed over the blue ice behind the mountain barrier is equal to that away from the mountains, when corrected for surface roughness and stability. This implies that use of diagnostic katabatic wind models to estimate divergence of drifting snow can be extended to the situation where nunataks are involved in preventing the drifting snow from passing, which is the case for most BIAs. A diagnostic model is tested for a two-dimensional profile in Terre Adélie. after which it is applied to entire East Antarctica. The present order-of-magnitude estimate shows that areas sensitive to blue-ice formation appear where precipitation is low and mean annual wind speed is high, i.e. in Dronning Maud Land and the drainage basin of Lambert Glacier. The results appeared to be especially sensitive to a change in inversion strength: a decrease in inversion strength weakens the katabatic flow, and thus the amount of snowdrift transport, reducing the area where BIAs can develop.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Winds Antarctica Mathematical models"

1

Sanz, Rodrigo Javier. "On antarctic wind engineering." Doctoral thesis, Universite Libre de Bruxelles, 2011. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209953.

Full text
Abstract:
Antarctic Wind Engineering deals with the effects of wind on the built environment. The assessment of wind induced forces, wind resource and wind driven snowdrifts are the main tasks for a wind engineer when participating on the design of an Antarctic building. While conventional Wind Engineering techniques are generally applicable to the Antarctic environment, there are some aspects that require further analysis due to the special characteristics of the Antarctic wind climate and its boundary layer meteorology.

The first issue in remote places like Antarctica is the lack of site wind measurements and meteorological information in general. In order to complement this shortage of information various meteorological databases have been surveyed. Global Reanalyses, produced by the European Met Office ECMWF, and RACMO/ANT mesoscale model simulations, produced by the Institute for Marine and Atmospheric Research of Utrecht University (IMAU), have been validated versus independent observations from a network of 115 automatic weather stations. The resolution of these models, of some tens of kilometers, is sufficient to characterize the wind climate in areas of smooth topography like the interior plateaus or the coastal ice shelves. In contrast, in escarpment and coastal areas, where the terrain gets rugged and katabatic winds are further intensified in confluence zones, the models lack resolution and underestimate the wind velocity.

The Antarctic atmospheric boundary layer (ABL) is characterized by the presence of strong katabatic winds that are generated by the presence of surface temperature inversions in sloping terrain. This inversion is persistent in Antarctica due to an almost continuous cooling by longwave radiation, especially during the winter night. As a result, the ABL is stably stratified most of the time and, only when the wind speed is high it becomes near neutrally stratified. This thesis also aims at making a critical review of the hypothesis underlying wind engineering models when extreme boundary layer situations are faced. It will be shown that the classical approach of assuming a neutral log-law in the surface layer can hold for studies of wind loading under strong winds but can be of limited use when detailed assessments are pursued.

The Antarctic landscape, mostly composed of very long fetches of ice covered terrain, makes it an optimum natural laboratory for the development of homogeneous boundary layers, which are a basic need for the formulation of ABL theories. Flux-profile measurements, made at Halley Research Station in the Brunt Ice Shelf by the British Antarctic Survery (BAS), have been used to analyze boundary layer similarity in view of formulating a one-dimensional ABL model. A 1D model of the neutral and stable boundary layer with a transport model for blowing snow has been implemented and verified versus test cases of the literature. A validation of quasi-stationary homogeneous profiles at different levels of stability confirms that such 1D models can be used to classify wind profiles to be used as boundary conditions for detailed 3D computational wind engineering studies.

A summary of the wind engineering activities carried out during the design of the Antarctic Research Station is provided as contextual reference and point of departure of this thesis. An elevated building on top of sloping terrain and connected to an under-snow garage constitutes a challenging environment for building design. Building aerodynamics and snowdrift management were tested in the von Karman Institute L1B wind tunnel for different building geometries and ridge integrations. Not only for safety and cost reduction but also for the integration of renewable energies, important benefits in the design of a building can be achieved if wind engineering is considered since the conceptual phase of the integrated building design process.


Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

APA, Harvard, Vancouver, ISO, and other styles
2

Berg, Allison M. "The feasibility of sodar wind profile measurements from an oceanographic buoy." Thesis, (37 MB), 2006. http://handle.dtic.mil/100.2/ADA471871.

Full text
Abstract:
Thesis (M.S.)--Massachusetts Institute of Technology at Woods Hole Oceanographic Institution, 2006.
"September 2006." Description based on title screen as viewed on June 8, 2010. DTIC Descriptor(s): Doppler Radar, Wind Velocity, Sound Ranging, Doppler Sonar, Buoys, Measurement, Motion, Oceanographic Equipment, Theses DTIC Identifier(s): Doppler Sodar, Sodar (Sound Detection and Ranging), ASIS Includes bibliographical references (leaf 75). Also available in print.
APA, Harvard, Vancouver, ISO, and other styles
3

Duhaut, Thomas H. A. "Wind-driven circulation : impact of a surface velocity dependent wind stress." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101117.

Full text
Abstract:
The use of an ocean surface velocity dependent wind stress is examined in the context of a 3-layer double-gyre quasigeostrophic wind-driven ocean circulation model. The new wind stress formulation results in a large reduction of the power input by the wind into the oceanic circulation. This wind stress is proportional to a quadratic function of Ua--u o, where Ua is the wind at 10m above the ocean surface and uo is the ocean surface current. Because the winds are typically faster than the ocean currents, the impact of the ocean surface velocity on the wind stress itself is relatively small. However, the power input is found to be greatly reduced with the new formulation. This is shown by simple scaling argument and numerical simulations in a square basin. Our results suggest that the wind power input may be as much as 35% smaller than is typically assumed.
The ocean current signature is clearly visible in the scatterometer-derived wind stress fields. We argue that because the actual ocean velocity differs from the modeled ocean velocities, care must be taken in directly applying scatterometer-derived wind stress products to the ocean circulation models. This is not to say that the scatterometer-derived wind stress is not useful. Clearly the great spatial and temporal coverage make these data sets invaluable. Our point is that it is better to separate the atmospheric and oceanic contribution to the stresses.
Finally, the new wind stress decreases the sensitivity of the solution to the (poorly known) bottom friction coefficient. The dependence of the circulation strength on different values of bottom friction is examined under the standard and the new wind stress forcing for two topographic configurations. A flat bottom and a meridional ridge case are studied. In the flat bottom case, the new wind stress leads to a significant reduction of the sensitivity to the bottom friction parameter, implying that inertial runaway occurs for smaller values of bottom friction coefficient. The ridge case also gives similar results. In the case of the ridge and the new wind stress formulation, no real inertial runaway regime has been found over the range of parameters explored.
APA, Harvard, Vancouver, ISO, and other styles
4

Hiester, Justin. "Investigations into the Regional and Local Timescale Variations of Subglacial Drainage Networks." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1022.

Full text
Abstract:
Subglacial water plays an important role in the regulation of an ice sheet's mass balance. It may be the dominant control on the velocities of ice streams and outlet glaciers on scales of months to millennia. Recent satellite observations of ice surface elevation changes have given researchers new insights into how subglacial water is stored and transported. Localized uplift and settling of the ice surface implies that lakes exist beneath the ice sheet that are being filled and drained on relatively short time scales. %At the base of an ice sheet water can be transported through a variety of drainage networks or stored in subglacial lakes. Here, a numerical investigation of the mechanisms of transport and storage of subglacial water and the associated time scales is presented. Experiments are carried out using a finite element model of coupled ice and water flow. The first experiment seeks to understand the relationship between the depth of a basal depression and the area over which the feature affects basal water flow. It is found that as the perturbation to a topographic depression's depth is increased, water is rerouted in response to the perturbation. Additionally it is found that the relationship between perturbation depth and the extent upstream to which its effects reach is nonlinear. The second experiment examines how the aspect ratio of bed features (prolate, oblate, or equidimensional) influences basal water flow. It is found that the systems that develop and their interactions are mediated by both the topography and the feedbacks taken into account by the coupling of the systems in the model. Features oriented parallel to ice and water flow are associated with distributed fan systems that develop branches which migrate laterally across the domain and interact with one another on monthly and yearly timescales. Laterally oriented features develop laterally extensive ponds. As the ratio of longitudinal to lateral dimension of the topography is increased, a combination of these two water distributions is seen.
APA, Harvard, Vancouver, ISO, and other styles
5

Waibel, Michael Scott. "A Numerical Model Investigation of the Role of the Glacier Bed in Regulating Grounding Line Retreat of Thwaites Glacier, West Antarctica." Thesis, Portland State University, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10259298.

Full text
Abstract:

I examine how two different realizations of bed morphology affect Thwaites Glacier response to ocean warming through the initiation of marine ice sheet instability and associated grounding line retreat. A state of the art numerical ice sheet model is used for this purpose. The bed configurations used are the 1-km resolution interpolated BEDMAP2 bed and a higher-resolution conditional simulation produced by John Goff at the University of Texas using the same underlying data. The model is forced using a slow ramp approach, where melt of ice on the floating side of the grounding line is increased over time, which gently nudges the glacier toward instability. Once an instability is initiated, the anomalous forcing is turned off, and further grounding line retreat is tracked.

Two model experiments are conducted. The first experiment examines the effect of different anomalous forcing magnitudes over the same bed. The second experiment compares the generation and progress of instabilities over different beds. Two fundamental conclusions emerge from these experiments. First, different bed geometries require different ocean forcings to generate a genuine instability, where ice dynamics lead to a positive feedback and grounding line retreat becomes unstable. Second, slightly different forcings produce different retreat rates, even after the anomalous forcing is shut off, because different forcing magnitudes produce different driving stresses at the time the instability is initiated. While variability in the retreat rate over time depends on bed topography, the rate itself is set by the magnitude of the forcing. This signals the importance of correct knowledge of both bed shape and ocean circulation under floating portions of Antarctic ice sheets. The experiments also imply that different ocean warming rates delivered by different global warming scenarios directly affects the rate of Antarctic contribution to sea level rise.

APA, Harvard, Vancouver, ISO, and other styles
6

Thornhill, Kenneth L. II. "An investigation of the environment surrounding supercell thunderstorms using wind profiler data." Diss., Georgia Institute of Technology, 1998. http://hdl.handle.net/1853/26958.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Williams, Timothy D. C., and n/a. "Reflections on ice : scattering of flexural gravity waves by irregularities in Arctic and Antarctic ice sheets." University of Otago. Department of Mathematics & Statistics, 2006. http://adt.otago.ac.nz./public/adt-NZDU20060907.120444.

Full text
Abstract:
This thesis studies the scattering properties of different types of imperfections in large Arctic and Antarctic ice sheets. Such irregularities include cracks, pressure ridges and both open and refrozen leads. The scattering by a transition region between sea ice and a very thick ice shelf, for example as is found in the Ross Sea in Antarctica, is also treated. Methods of solution are based on applications of Green�s theorem to the appropriate situation, which leads to either a single integral equation or a pair of coupled integral equations to be solved at the boundary between the ice and the sea water. Those equations over a finite interval are solved using numerical quadrature, while those over semi-infinite ranges are solved using the Wiener-Hopf method. Results calculated using different techniques are able to be checked against each other, giving us great confidence in their accuracy. In particular, the scattering by three ice sheets of different thicknesses is confirmed analytically by mode-matching coupled with the residue calculus technique. The scattering by the single irregularities is investigated partly for its own sake, and partly with the aim of using it to treat the scattering when large numbers of features are included in a single ice sheet. The principal objective of doing this is to observe the change in the general amounts of reflection and transmission as the background ice thickness is changed. There is enough variation in our results for us to conclude that there is definite potential for using the change in an incident wave spectrum after passing through a given ice field to estimate the background ice thickness.
APA, Harvard, Vancouver, ISO, and other styles
8

Downer, Joshua, and n/a. "The influence of ocean waves on the distribution of sea ice in an MIZ." University of Otago. Department of Mathematics & Statistics, 2005. http://adt.otago.ac.nz./public/adt-NZDU20070202.120522.

Full text
Abstract:
A marginal ice zone (MIZ) is characterised by distinct ice floes and its direct exposure to the open ocean. Sea ice is typically described as a continuous material but this description can be inappropriate in an MIZ due to the granular nature of the ice cover and the scale of processes acting on the ice floes. In this thesis, the kinematic behaviour of sea ice in an MIZ modelled as a granular material is investigated with an emphasis on the influence of ocean waves. The kinematic behaviour of a set of ice floes subject to ocean wave forcing was recorded in an experiment conducted in the Ross Sea. Kinematic data were recorded from each ice floe using a GPS receiver, tri-axial accelerometer, and compass. The data show (1) the influence of wave forcing and (2) collisions between neighbouring ice floes. It was also discovered that the GPS receivers were able to resolve the effects of ocean wave forcing despite their poor absolute accuracy. The number density and normalised structure factor (NSF) are introduced to describe the spatial structure of a set of ice floes. Four idealised distributions (in 1D and 2D) are analysed to gain insight into the way that different factors determine the shape of the NSF. It is shown that (1) a significant sinusoidal deviation causes a peak in the NSF, (2) ordered structure dominates low spatial frequencies, and (3) disorder dominates high spatial frequencies. A comparison of the contributions from these different factors is used to estimate the significance of a sinusoidal deviation in the positions of the ice floes. A granular model of an MIZ is developed using a novel set of equations of motion to examine the effect of ocean wave forcing. The equations of motion are derived for small ice floes and allows forcing by multiple waves. These equations predict a transient, wave-induced torque, which can be sustained by the application of a second force to the ice floe. Torque induced by the interaction of two forces on an ice floe may be a general feature of sea ice motion. The number density and NSF are used to analyse the distribution of ice floes in the granular model. At low solids-fractions the number density is correlated at the frequency of the wave forcing. As the solids-fraction is increased this correlation is destroyed by collisions between the ice floes and new correlations are created that are related to the packing structure of the ice floes. When the number density is weighted by the velocity of the ice floes, the correlations between floes are related to the convolution of the wave velocity field and the number density. These correlations may be incorporated into the thickness distribution of large-scale models using the maximum entropy method. The granular model was also examined as a percolating network of contacts and it was found that percolation was more likely to occur along the crest of a wave than in the direction of propagation.
APA, Harvard, Vancouver, ISO, and other styles
9

Moodley, Kirshnee. "The fitting of statistical distributions to wind data in coastal areas of South Africa." Thesis, Nelson Mandela Metropolitan University, 2013.

Find full text
Abstract:
Coastal South African cities like Port Elizabeth are said to have a strong potential for wind energy. This study aims to model wind data in order to be able assess the power potential belonging to a given site. The main challenge in modelling wind direction data is that it is categorized as circular data and therefore requires special techniques for handling that are different from usual statistical samples. Statistical tools such as descriptive measures and distribution fitting, were re-invented for directional data by researchers in this field. The von Mises distribution is a predominant distribution in circular statistics and is commonly used to describe wind directions. In this study, the circular principles described by previous researchers were developed by using the statistical software, Mathematica. Graphical methods to present the wind data were developed to give an overview of the behaviour of the winds in any given area. Data collected at Coega, an area near Port Elizabeth, South Africa, was used to illustrate the models which were established in this study. Circular distributions were fit to the directional data in order to make appropriate conclusions about the prevailing wind directions in this area.
APA, Harvard, Vancouver, ISO, and other styles
10

Zelenke, Brian Christopher. "An empirical statistical model relating winds and ocean surface currents : implications for short-term current forecasts." Thesis, Connect to the title online, 2005. http://hdl.handle.net/1957/2166.

Full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Winds Antarctica Mathematical models"

1

Klein, Thomas. Katabatic winds over Greenland and Antarctica and their interaction with mesoscale and synoptic scale weather systems: Investigations using three dimensional numerical models. St. Augustin: Asgard, 2000.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Melgarejo, José W. An analytical model of the boundary layer above sloping terrain with an application to observations in Antarctica. Norrköpping: SMHI, 1986.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Wuertz, David B. Editing wind profiler measurements. Boulder, Colo: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, Environmental Research Laboratories, Wave Propagation Laboratory, 1989.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Wuertz, David B. Editing wind profiler measurements. Boulder, Colo: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, Environmental Research Laboratories, Wave Propagation Laboratory, 1989.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Wuertz, David B. Editing wind profiler measurements. Boulder, Colo: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, Environmental Research Laboratories, Wave Propagation Laboratory, 1989.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Klaus, Braun. Der Einfluss mesoskaliger Windfelder auf die räumliche Verteilung des Niederschlags: Eine Untersuchung zur Regionalisierung von Niederschlagsdaten mit Hilfe eines mesoskaligen Strömungsmodells. Freiburg: Im Selbstverlag des Institutes für Physische Geographie der Albert-Ludwigs-Universität Freiburg i. Br., 1997.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Rennick, Mary Alice. Solutions to the shallow water equations in an ocean basin forced by unsteady winds. Monterey, Calif: Naval Postgraduate School, 1988.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Schuhmacher, Peter. Messung und numerische Modellierung des Windfeldes über einer Stadt in komplexer Topographie. Zürich: Verlag der Fachvereine Zürich, 1992.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

Schwenzfeger, K. J. Comparison of ERS-1 scatterometer Monte Carlo performance simulations using a weighted nonlinear least-squares and a maximum likelihood estimation method. Neubiberg: Hochschule der Bundeswehr München, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

Schwenzfeger, K. J. Auswertung von gemessenen Rückstreukoeffizienten im Hinblick auf bestehende Windfelder. Neubiberg: Universität der Bundeswehr München, 1985.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Conference papers on the topic "Winds Antarctica Mathematical models"

1

Verma, Himanshu, Ashish M. Dighe, and Peter Hagedorn. "On the Solution of Transcendental Eigenvalue Problem in Transmission Line Bundled Conductors." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-60901.

Full text
Abstract:
Overhead electrical transmission lines are always susceptible to aeolian vibrations, caused by light to moderate winds. Spacer dampers are used in bundled transmission lines to keep the conductors at required minimum spacing and to suppress the wind induced vibrations. Mathematical models are necessary for the computation of the conductor vibrations for studying the efficiency of damping measures. The so called energy balance method gives good results for estimating the vortex excited vibrations of overhead electrical transmission lines. In its standard form it requires the knowledge of the eigenfunctions, which are routinely calculated for the single conductor lines. However, the problem becomes more involved in the case of bundled conductors with spacer dampers due to very dense spectrum of the natural frequencies. In the present paper some approaches towards solving the transcendental eigenvalue problem (EVP) for the bundled conductors with spacer dampers are discussed. It is formulated as an algebraic transcendental EVP, which however presents several numerical difficulties. Reasons for these numerical difficulties are discussed in some detail. A new approach, named as “continuous spectrum approach,” provides better engineering solution for the transmission line bundled conductors. The solution of the EVP gives the necessary input data for applying the energy balance.
APA, Harvard, Vancouver, ISO, and other styles
2

Tannuri, Eduardo A., Helio M. Morishita, Vinicius L. M. Veras, and Glenan A. Lago. "Critical Analysis of Control and Filtering Algorithms Used in Real Dynamic Positioning Systems." In ASME 2005 24th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2005. http://dx.doi.org/10.1115/omae2005-67137.

Full text
Abstract:
Dynamic positioning systems (DPS) comprise the utilization of active propulsion to maintain the position and heading of a vessel. Sensors are used to measure the actual position of the floating body, and a control algorithm is responsible for the calculation of forces to be applied to each propeller, in order to counteract all environmental forces, including wind, waves and current loads. The controller cannot directly compensate motions in the sea waves frequency range, since they would require an enormous power to be attenuated, possibly causing damage to the propeller system. A filtering algorithm is then used to separate high frequency components from the low frequency ones, which are indeed controlled. Usual commercial systems apply Kalman filtering technique to perform such task, which includes a full model of the system. Furthermore, an adaptive on-line estimation algorithm is also used to evaluate the wave peak frequency, since the model in Kalman Filter depends on such parameter. The controller itself is based on a simple proportional-derivative (PD) actions. This paper presents all the mathematical formulation of the Kalman Filter, adaptive algorithm and the controller used in commercial DPS and performs a critical analysis of those models. Some illustrative results of a dynamic positioned shuttle vessel are presented, considering the incidence of waves, current and winds.
APA, Harvard, Vancouver, ISO, and other styles
3

Kupciuniene, Kristina, and Robertas Alzbutas. "External Events Importance for Safety of the Ignalina Nuclear Power Plant." In 16th International Conference on Nuclear Engineering. ASMEDC, 2008. http://dx.doi.org/10.1115/icone16-48230.

Full text
Abstract:
Probabilistic risk analysis of external events impact on the safety important systems of Ignalina nuclear power plant (NPP) is performed. At first, the methodology was established for screening out external events, which impact on Ignalina NPP safety is not significant. In order to estimate probabilities of external events occurrences the statistical data were collected, mathematical models were constructed and probabilities of these events occurrences were determined. For risk estimation, the following external events were studied: forest fires, external floods, aircraft crash, seismic events, extreme winds, fall of frequency in electricity network and loss of an external electricity supply. The aircraft crash event was modeled and analyzed in more detail. The crash probability estimation model is improved considering uncertain data. The aircraft crash probability on the territory of the Ignalina NPP with the radius r is expressed by the derived analytical formula. This formula is used to calculate the aircraft crash probability applying the most recent statistical data. The aircraft crash dependencies upon the amount of flights and crashes in the different radius territories were analyzed. Relationship of non-flying zone around Ignalina NPP and aircraft crash frequency was investigated. As a part of the initial conditions and parameters of aircraft crash model are not well-known or have different values for various types of aircrafts, the sensitivity analysis was performed for the model. This analysis determines the parameters that have the greatest influence on the model results. Conclusions about the importance of the parameters and sensitivity of the results are obtained using a sensitivity measures of the model under analysis.
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Winds Antarctica Mathematical models' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography