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Energy dissipation in atmospheric flowStansfield, John Mills 08 1900 (has links)
No description available.
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A parametric study of the momentum flux at the air-sea interface /Lowe, Steven J., January 1993 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 42-43). Also available via the Internet.
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Subseasonal variability in the Southern Hemisphere as simulated by a two-level atmospheric general circulation modelTomas, Robert A. 17 June 1987 (has links)
The dynamical nature of atmospheric disturbances in
the Southern Hemisphere simulated by a two-level general
circulation (GCM) model is studied. Time series of the
dependent variables and diabatic heating components from
10 Southern Hemisphere winters (JJA) and summers (DJF)
simulated by the Oregon State University two-level GCM are
used. The time mean fields are presented and discussed.
Variance and covariance analyses are performed to
determine the geographical distribution, intensities and
transport properties of high-frequency (periods between
2.5 and 10 days) and low-frequency (periods between 10
days and a season) transient eddies. These are discussed
in terms of dynamical consistency with the time-mean
circulation.
It is found that the behavior of the high-frequency
eddies at mid and high-latitudes is consistent with
baroclinic instability theory, i.e., the eddies have
properties similar to observed migratory weather
disturbances. The low-frequency eddies appear to be
quasi-stationary Rossby waves originating at middle
latitudes. They seem to disperse energy in a manner
consistent with arguments based on simple linear wave
dynamics. During wintertime, the time mean flow directs
eddies poleward where they grow by baroclinic processes.
Also during wintertime, the slow phase velocity, fast
group velocity and cyclic domain lead to quasi-resonant
behavior on a hemispheric scale. / Graduation date: 1988
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A model for turbulent diffusion in the atmosphereMani, Kothappallyl Kurian 08 1900 (has links)
No description available.
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A parametric study of the momentum flux at the air-sea interfaceLowe, Steven J. 10 June 2009 (has links)
A modified eddy correlation technique is applied to data obtained from a field experiment conducted in the Bight of Abaco during the Spring of 1990. The experiment yielded 3408 30 minute records of turbulent wind data sampled at 5 Hz. Wind stress estimates were successfully calculated for 3182 of these. The modification to the eddy correlation technique involved extending the cospectra to higher frequencies than were measured by the propeller anemometer to obtain a better estimate to the <i>uw</i> covariance. This resulted in a small increase to the <i>uw</i> covariance, and hence the drag coefficient. / Master of Science
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Linking dynamics of the near-surface flow to deeper boundary layer forcing in the nocturnal boundary layerSmoot, Alexander R. 01 June 2012 (has links)
Weak-wind flow in the nocturnal boundary is one of the most poorly understood problems in the field of meteorology. The understanding of weak-wind flows is essential for the improvement of regulatory dispersion models which are currently rendered invalid under weak-wind conditions and stable stratification. Recently there have been increased efforts directed towards improving the understanding nocturnal boundary layer dynamics. The results of these studies have shown that nocturnal boundary layer flows are often dominated by intermittent turbulence and motions occurring on horizontal scales ranging from hundreds of meters to several kilometers and on time scales of 1 minute to 1 hour. We refer to these scales as sub-meso. This connection has led to the hypothesis that intermittent turbulence generation may be the result of sub-meso motions that are subject to external forcing originating in the deeper boundary layer. However, these processes have proven difficult to measure as traditional sensor networks have failed to provide the vertical and horizontal coverage necessary to observe the driving forces on these scales. This study sought to close this knowledge gap using SOund Detection And Ranging (SODAR). SODAR is a ground based acoustic remote sensing technology that is capable of measuring wind and turbulence at multiple heights in the boundary layer. Data were collected with a pair of SODAR systems with sequentially increasing separation distance at the Oregon State University Botany and Plant Pathology lab during the summer of 2010. The data have indicated that motion occurring on time scales of 2 minutes to 32 minutes are isolated to the lowest 50 meters of the nocturnal boundary layer. Surface-layer measurements were collected using a pair of sonic anemometers placed at heights of 1.5 and 7 meters above ground level. Comparisons of surface-layer measurements and deeper boundary layer measurements have shown that when the surface layer stratification is stable, processes within the surface layer are not likely to be influenced by external forcing from aloft. In contrast external forcing from the deeper boundary layer may still have an influence on weak, nocturnal surface flows when the surface layer is weakly stratified as is shown for the case of low-level jets. / Graduation date: 2013
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Transfer coefficient in a crop by electrochemical analogWhite, Kenneth D. January 1974 (has links)
No description available.
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Turbulent entrainment fluxes within the eastern Pacific warm pool /Mickett, John B. January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Vita. Includes bibliographical references (p. 145-156).
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Enrichment of The Intergalactic MediumShen, Sijing 09 1900 (has links)
<p> A study of metal enrichment of the intergalactic medium (IGM) using a series
of smooth particle hydrodynamics (SPH) simulations is presented, employing
models for metal cooling and the turbulent diffusion of metals and thermal
energy. An adiabatic feedback mechanism was adopted where gas cooling was
prevented on the timescale of supernova bubble expansion to generate galactic
winds without explicit wind particles. The simulations produced a cosmic star
formation history (SFH) that is broadly consistent with observations until z
~ 0.5, and a steady universal neutral hydrogen fraction (OHI) that compares
reasonably well with observations. The evolution of the mass and metallicities
in stars and various gas phases was investigated. At z=O, about 40% of the
baryons are in the warm-hot intergalactic medium (WHIM), but most metals
(80%-90%) are locked in stars. At higher redshifts the proportion of metals
in the IGM is higher due to more efficient loss from galaxies. The results also
indicate that IGM metals primarily reside in the WHIM throughout cosmic
history, which differs from simulations with hydrodynamically decoupled explicit
winds. The metallicity of the WHIM lies between 0.01 and 0.1 solar
with a slight decrease at lower redshifts. The metallicity evolution of the gas
inside galaxies is broadly consistent with observations, but the diffuse IGM is
under-enriched at z ~ 2.5. Metals enhance cooling which allows WHIM gas to
cool onto galaxies and increases star formation. Metal diffusion allows winds
to mix prior to escape, decreasing the IGM metal content in favour of gas
within galactic halos and star forming gas. Diffusion significantly increases
the amount of gas with low metallicities and improves the density-metallicity
relation. </p> <p> The galactic wind generation mechanism and the wind properties from
our simulations were investigated. It was found that: 1. Galactic winds are
most efficient for halos in the intermediate mass range 10^10Mo - 10^11 Mo . These winds dominate the metal ejection at all redshifts, although towards
lower redshift the contributions from larger halos become relatively more important.
At the low mass end gas is prevented from accreting onto halos and
has very low metallicities. At the high mass end, the fraction of halo baryons
escaped as winds declines along with the decline of stellar mass fraction in
these halos. The decrease in wind ejection is likely because of the decreases
in star formation activity, wind mass loading and wind escape efficiency as
the halo mass increases. 2. The adiabatic feedback can generate winds with
mass loading factors comparable to the ones used in explicit superwind models.
The mass loading factor decreases towards lower redshift, implying that
smaller halos have larger mass loading. 3. Metals located at lower density
were generated at earlier epochs from small halos, suggesting that the wind
traveling speed can affect the metal distribution in the IGM. </p> / Thesis / Doctor of Philosophy (PhD)
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Scaling laws for turbulent relative dispersion in two-dimensional energy inverse-cascade turbulence / 2次元エネルギー逆カスケード乱流における乱流相対拡散のスケーリング則Kishi, Tatsuro 23 March 2021 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第22984号 / 理博第4661号 / 新制||理||1669(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)准教授 藤 定義, 教授 佐々 真一, 教授 早川 尚男 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
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