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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Inter-annual variability of marine biogeochemistry at the SEATS site: application of a one-dimensional coupled physical-biogeochemical model

Wang, Li-Wen 12 September 2007 (has links)
In this study, a one-dimensional model based on the Mellor and Yamada level 2.5 turbulence closure model was coupled with a biogeochemical model to investigate the inter-annual variation of biogeochemistry at the South-East Asian Time-series Study (SEATS) Site in the northern South China Sea (SCS) from 1997 to 2003. During the study period there were two El Niño Events and two La Niña Events. This study was focused on the hydrographic and biogeochemical conditions during these events. In order to better understand the model performance in the physical and biogeochemical aspects, numerical experiments were conducted to investigate the key processes. Numerical experiments by using idealized forcing conditions revealed that stronger wind stresses resulted in stronger cooling and deeper mixed layer. The model results were as sensitive to the initial density structure of the water column as to wind stress. Numerical experiments with the coupled model revealed that the biogeochemical results are insensitive to the initial biogeochemical conditions except the nitrate profile. Sensitivity tests indicated that primary production was sensitive to the remineralization rate constant for the detritus and parameters related to zooplankton, such as growth rate, grazing constant and mortality rate constant. It is less sensitive to iv aggregation constant of phytoplankton. The SEATS project of the National Center for Ocean Research provided data of sea surface chlorophyll-a (S-chl) concentrations, which were derived from SeaWiFS data for the period from Jan. 1997 to Dec. 2003 by calibrating against shipboard observations. The time-series showed decreases of mean S-chl by 35% and 9% below the climatological mean in the winter months (DJF) of the two El Niño Events. The negative S-chl anomalies corresponded to elevated sea surface temperature (SST) by 1.4oC and 0.4oC above the climatological mean, while the mean wind speed (WS) was reduced by 20% and 13%, and the surface heat exchange reverted from net loss to net gain or null. It is hypothesized that the anomalously low S-chl may have been caused by the weakened wind mixing and strengthened stratification. A 1-dimensional coupled physical-biogeochemical model was developed to test this hypothesis. The model driven by wind stress and surface heat fluxes successfully reproduced the seasonal cycles of S-chl and integrated primary productivity (IPP) as compared to shipboard observations and SeaWiFS data derived values, and predicted the negative anomalies of S-chl and IPP under the 1997-98 and 2002-03 El Niño conditions. However, the model-predicted strong positive anomalies of S-chl and IPP under the 1998-99 and 1999-2000 La Niña conditions, which brought v stronger wind and heat loss, were not substantiated by observations. Hydrographic conditions at the SEATS station indicated that, under La Niña conditions, unusual accumulation of warm and nutrient-depleted water occurred in the upper water column cancelled out the effect of stronger mixing. Therefore, the biogeochemical responses of the northern SCS to surface forcing during the recent El Niño/La Niña conditions displayed in a highly asymmetrical manner.
12

Nino Rotas trombonkonsert

Nilsson, Thobias January 2014 (has links)
I det här arbetet fördjupar jag mig i första satsen av Nino Rotas trombonkonsert. Nino Rota var en italiensk kompositör som var mest känd för sin filmmusik, och då särskilt musiken till Gudfadern I och Gudfadern II, men har även skrivit en stor mängd konsertmusik. Hans filmvana avspeglar sig även på hans konsertmusik. Jag gör i arbetet en motivkatalog, och en fördjupad interpretationsdel där jag tar upp hur jag vill att satsen ska spelas samt svårigheter med att få den just så. Slutligen bifogar jag en inspelning av satsen från min examenskonsert. / <p>Bilaga: 1 CD</p><p>Nino Rota, Konsert för trombonMedverkande:Trombon - Thobias NilssonPiano - Katarina Ström-Harg</p>
13

THE ROLE OF CLIMATE VARIABILITY IN OPERATIONAL WATER SUPPLY FORECASTING FOR THE WESTERN UNITED STATES

Pagano, Thomas Christopher, Pagano, Thomas Christopher January 2005 (has links)
The single greatest uncertainty in seasonal water supply forecasts is the amount of precipitation falling after the forecast issue date. There has been a long history of attempting to incorporate seasonal climate forecasts into operational water supply forecasts. The skill of these precipitation forecasts remains low especially compared to highly confident snow-based streamflow forecasts. Early in the season (e.g., September-December), however, large-scale climate indices are the best available predictors of future water supplies. This dissertation suggests practical methods for issuing climate-based operational streamflow forecasts.This study also documents the existence of strong decadal trends in water supply forecast skill. Across the Western US, 1 April forecast skill peaked in the 1960-1970s and has been on the decline more recently. The high skill period was a very calm period in the Western US, with a near absence of extreme (wet or dry) spring precipitation events. In contrast, the period after 1980 has had the most variable, persistent, and skewed spring and summer streamflows in the modern record. Spring precipitation is also now more variable than it has been since at least the 1930s. This rise in spring precipitation variability in the Colorado/Rio Grande Basins and the Pacific Northwest is the likely cause behind the recent decline in water supply forecast skill.
14

Safe Yield for Jointly Operated Reservoir System and Examination of ENSO Impacts

Sachan, Amit 20 June 2003 (has links)
Determination of safe yield of a water source is a basic aspect of water supply planning. In this report, the safe yield is defined as the maximum constant release from a reservoir that is possible during a selected drought period. The yield depends on drought magnitude and duration controlled by nature and ability to manipulate the releases through man made controls in the form of impoundment structures and regulations. A water supply system with two reservoirs in series and one in parallel in Spotsylvania County — the Hunting Run Reservoir, the Motts Run Reservoir (in series), and the Ni River Reservoir is considered to demonstrate the yield calculations. When several reservoirs are considered, the critical periods (defined as the period from full storage to empty condition) may not coincide and the system must be analyzed for the binding critical duration. A zero-one linear integer programming formulation is proposed to compute the system yield. The formulation accommodates the various storage and river flow dependent instream flow requirements. It is found that the water treatment plant capacity, instream flow requirements, and flows themselves limit the yield. Inflows to the reservoir are very important factor in determination of safe yield for any system of reservoirs. Changes in the precipitation hence inflows may cause a significant effect on the operation of reservoir. El Nino and La Nina phenomena, which occur due to changes in the atmospheric condition over the equatorial Pacific region, are found to affect the global climate in different studies. To examine the changes in the precipitation / streamflows due to El Nino and La Nina events on the safe yield, studies are done on the streamflows in the study area and four regions across the world during El Nino and LA Nina events. Lag correlation studies and descriptive analysis of the streamflows in the study region in Northern Virginia fail to show any pattern in the streamflow changes due to El Nino and La Nina events, based on the available data. However, this observation is not conclusive and further research if needed. / Master of Science
15

A Global Survey of Clouds by CloudSat

Riley, Emily Marie 01 January 2009 (has links)
With the launch of CloudSat, direct observations of cloud vertical structure became possible on the global scale. This thesis utilizes over two years of CloudSat data to study large-scale variations of clouds. We compose a global data set of contiguous clouds (echo objects, EOs) and the individual pixels comprising each EO. For each EO many attributes are recorded. EOs are categorized according to cloud type, time of day, season, surface type, and region. From the categorization we first look at gross global climatology of clouds. Maps of cloud cover are subdivided by EO (cloud) type, and results compare well with previous CloudSat work. The seasonality of cloud cover is also examined. Focus topics studied in this thesis include: (1) mid-level clouds, (2) stratocumulus clouds, and (3) clouds across the Madden-Julian Oscillation (MJO). The mid-level cloud work found an unexpected frequency peak in EO top heights between 7-8 km in the tropics, further shown to correspond to a global peak in EO top temperature between -15°C ? -20°C. Hypotheses are discussed regarding cause of this feature. Stratocumulus clouds are defined as low-level (tops < 4.5 km), wide (width > 11 km) EOs. Stratocumulus cloud cover agrees (with understandable differences) with other estimates (ISCCP and CALIPSO). The seasonal cycle of stratocumulus over the main stratocumulus decks is examined. The Peruvian and Namibian decks have increased cloud cover in austral spring in 2007 vs. 2006, corresponding sensibly to sea surface temperature differences and changes in lower static stability. Looking at rain and drizzle statistics, wider EOs are found to drizzle more. Clouds across the MJO are defined relative to temporally filtered OLR data. Cloud cover (volume) doubles (triples) from suppressed to active MJO phases, with some shifts of the relative contributions of different EO types from the front to back of the MJO. Pixel statistics in dBZ-height space correspond to these cloud-type shifts. High anvils and low clouds in front lead deep convection followed by relatively lower anvils in the back.
16

An Analysis of the Concerto for bassoon and orchestra by Nino Rota

January 2012 (has links)
abstract: Nino Rota was a prolific composer of twentieth-century film and concert music, including the Concerto for bassoon and orchestra in b-flat major. Composing over 150 film scores for directors such as Federico Fellini, Francis Ford Coppola, Henry Cass, King Vidor and Franco Zeffirelli, Rota received distinguished acclaim from several film institutions, professional film reviewers and film music experts for his contributions to the art form. Rota also composed a great deal of diverse repertoire for the concert stage (ballet, opera, incidental music, concerti, symphonies, as well as several chamber works). The purpose of this analysis is to emphasize the expressive charm and accessibility of his concerto in the bassoon repertoire. The matter of this analysis of the Concerto for bassoon and orchestra concentrates on a single concerto from his concert repertoire completed in 1977, two years before Rota's death. The discussion includes a brief introduction to Nino Rota and his accomplishments as a musician and film composer, and a detailed outline of the motivic and structural events of contained in each movement of the concerto. The shape of the work is analyzed both in detailed discussion and by the use of charts, including reduced score figures of excerpts of the piece, which illustrate significant thematic events and relationships. The analysis reveals how Rota uses lyrical thematic material in a consistently, and he develops the music by creating melodic sequences and varied repetitions of thematic material. He is comfortable writing several forms, as indicated by the first movement, Toccata - a sonata-type form; the second movement, Recitativo, opening with a cadenza and followed by a theme and brief development; and the third movement, a theme (Andantino) and set of six variations. Rota's writing also includes contrapuntal techniques such as imitation, inversion, retrograde and augmentation, all creating expressive interest during thematic development. It is clear from the discussion that Rota is an accomplished, well-studied and lyrical composer. This analysis will inform the bassoonist and conductor, and aid in developing a fondness for the Concerto for bassoon and orchestra and perhaps other concert works. / Dissertation/Thesis / D.M.A. Music 2012
17

Les textes de chansons : entre le langage et la musique : (sur l'exemple de la chanson d'auteur des années 1950-1980) / Song lyrics : where language meets music : (a study of the French chanson d’auteur, 1950s – 1980s)

Savtchenko, Mikhail 14 December 2015 (has links)
Le travail est consacré au texte de chanson en tant que phénomène. La chanson étant un genre synthétique, les modes de coopération entre ses deux principaux univers, le texte et la musique, sont étudiés, afin de voir quels effets de sens produit leur coexistence. Cela est réalisé sur l’exemple de la chanson française des années 1950-1980 : à l’intérieur de cette période, trois auteurs (Serge Gainsbourg, Boby Lapointe, Nino Ferrer) ont été choisis, dont la similitude des styles permet de les regrouper sous la même appellation de « chanson formaliste ». Ce type de chanson affiche un intérêt particulier pour les jeux linguistiques (calembours, allitérations) et autres procédés rhétoriques ou ludiques (pastiches, parodies) et met en œuvre une intertextualité riche. Ce caractère est souvent paradoxal, car la musique, qui dicte des contraintes comparables à l’état du vers français à l’époque métrique, gomme certains de ces effets formels, et le genre chanson en général tolère mal les jeux linguistiques complexes. Le statut problématique du texte de chanson est lié au fait que, techniquement, il ne diffère guère du poème et peut être mis dans le même contexte culturel (notamment en étant publié ou récité), alors que son mode de fonctionnement n’est pas le même. L’analyse des textes de la chanson formaliste révèle que si les procédés utilisés par Gainsbourg, Lapointe et Ferrer existent aussi dans la poésie, le texte de chanson possède des caractéristiques qui lui sont propres, notamment un rapport nécessaire avec les autres éléments de la chanson (la musique, la performance), ainsi que la linéarité temporelle. / The thesis studies song lyrics as a concept. As the song is a synthetic genre, the modes of interaction between its two main domains, words and music, are studied, along with the effects of their coexistence. The example used it that of the French chanson of the 1950s – 1980s. Within this period, the study focuses on three authors (Serge Gainsbourg, Boby Lapointe, Nino Ferrer), whose songs, on account of their stylistic similarities, can be considered examples of the “formalist chanson”. This type of chanson prefers linguistic play (puns, alliteration) and other rhetorical or play-oriented devices (pastiche, parody), and makes heavy use of intertextuality. This is often a paradox, as music, as it entails constraints comparable to those of metric poetry, often minimizes formal effect; indeed, the genre of chanson in general is ill-suited to complex wordplay. The song lyric is problematic because whereas it is technically identical to the poem, and can also be put in the same cultural context (in particular, by being published or read aloud), the principles of its functioning are not the same. The analysis of “formalist chanson” lyrics reveals that while the devices used by Gainsbourg, Ferrer and Lapointe can also be found in poetry, the song lyric nonetheless possesses distinguishing features: in particular its dependency on the other elements of the song (music and performance), but also its temporal linearity.
18

Derechos y Constitucionalismo Discursivo

Lozada, Alí 01 February 2016 (has links)
No description available.
19

The Influence of Disease and Climate on Pinniped Species at Local and Regional Scales

Dixon, Katherine P. 01 June 2017 (has links)
No description available.
20

L'onde de Kelvin équatoriale océanique intrasaisonnière et les événements El Nino du Pacifique central / The intraseasonal equatorial oceanic Kelvin wave and the central Pacific El Nino phenomenon

Mosquera Vasquez, Kobi A. 03 July 2015 (has links)
Le phénomène El Niño est le mode dominant de la variabilité du climat aux échelles de temps interannuelles dans le Pacifique tropical. Il modifie considérablement le climat régional dans les pays voisins, dont le Pérou pour lequel les impacts socio-économiques peuvent être dramatiques. Comprendre et prévoir El Niño reste un enjeu prioritaire pour la communauté climatique. Des progrès significatifs dans notre compréhension du phénomène El Niño et dans notre capacité à le prédire ont été réalisés dans les années 80, en particulier grâce à la mise en place du système d'observation dans le Pacifique tropical (programme de TOGA, en particulier, ainsi que l'émergence de l'ère des satellites). À la fin du XXe siècle, alors que de nouvelles théories scientifiques ont été proposées et testées, les progrès réalisés dans le domaine de la modélisation numérique et de l'assimilation de données ont conduit à l'idée que le phénomène El Niño pourrait être prévu avec au moins deux ou trois saisons à l'avance. Or, depuis le début du 21ième siècle, les manifestations du phénomène El Niño ont réduit cette expectative: un nouveau type d'El Niño est a été découvert - identifié par des anomalies de température moins intenses et localisées dans le centre du Pacifique équatorial. Ce phénomène, connu sous le nom CP El Niño pour El Niño Pacifique Central ou El Niño Modoki a placé la communauté scientifique devant un nouveau défi. Cette thèse est une contribution à l'effort international actuel pour comprendre la dynamique de ce nouveau type d'El Niño, dans le but de proposer des mécanismes expliquant sa présence accrue au cours des dernières décennies. Plus précisément, l'objectif de cette thèse est d'étudier le rôle des ondes longues équatoriales dans le Pacifique tropical sur la dynamique océanique et la thermodynamique associées au phénomène El Niño de type Pacifique Central. Cette thèse s'intéresse tout d'abord au premier CP El Niño du 21ième siècle, le phénomène El Niño 2002/03, à partir des sorties d'un modèle de circulation océanique général. Ensuite, nous documentons les caractéristiques des ondes équatoriales de Kelvin aux fréquences Intra Saisonnières (ISKw) sur la période 1990-2011, fournissant une statistique de l'activité des ondes ISKw durant l'évolution des événements El Niño de type Central Pacifique. Nos résultats montrent que l'onde ISKw subit une forte dissipation dans le Pacifique Est, qui est interprétée comme provenant de la dispersion des ondes lorsqu'elles rencontrent le front zonal de la stratification dans l'Est du Pacifique (i.e. la pente de la thermocline d'Ouest en Est). Une réflexion partielle de l'onde ISKw en onde de Rossby équatoriale de près de 120°W est également identifiée, ce qui peut expliquer le confinement dans le Pacifique central des anomalies de température de surface associées aux événements El Niño de type Central Pacifique. Nous suggérons que la fréquence accrue au cours des dernières années des événements CP El Niño peut être associée à l'état froid - de type La Niña - observé dans le Pacifique Equatorial depuis les années 90 et les changements dans la variabilité saisonnière de la profondeur de la thermocline depuis les années 2000. / The El Niño phenomenon is the dominant mode of climate variability at interannual timescales in the tropical Pacific. It modifies drastically the regional climate in surrounding countries, including Peru for which the socio-economical impacts can be dramatic. Understanding and predicting El Niño remains a top-priority issue for the climatic community. Large progress in our understanding of El Niño and in our ability to predict it has been made since the 80s thanks to the improvement of the observing system of the tropical Pacific (TOGA program and emergence of the satellite era). At the end of the Twentieth century, whereas new theories were proposed and tested, progress in numerical modeling and data assimilation led to the idea that El Niño could be predicted with at least 2 or 3 seasons in advance. The observations since the beginning of the 21st century have wiped out such expectation: A new type of El Niño, known as the Central Pacific El Niño (CP El Niño) or Modoki El Niño has put the community in front of a new challenge. This thesis is a contribution to the current international effort to understand the dynamics of this new type of El Niño in order to propose mechanisms explaining its increased occurrence in recent decades. More specifically, the objective of the thesis is to study the role of the oceanic equatorial waves in the dynamic and thermodynamic along the equatorial Pacific Ocean, focusing on the CP El Niño. This thesis first takes a close look at the first CP El Niño of the 21st century of this type, i.e. the 2002/03 El Niño, based on an Oceanic General Circulation Model. Then it documents the characteristics of the IntraSeasonal Kelvin waves (ISKws) over the period 1990-2011, providing a statistics on the ISKws activity during the evolution of CP El Niño events. We find that the ISKw experiences a sharp dissipation in the eastern Pacific that is interpreted as resulting from the scattering of energy associated to the zonal contrast in stratification (i.e. sloping thermocline from west to east). Partial reflection of the ISKw as Rossby waves near 120°W is also identified, which may explain the confinement of CP El Niño warming in the central Pacific. We suggest that the increased occurrence of CP El Niño in recent years may be associated to the La Niña-like state since the 90s and changes in the seasonality of the thermocline since the 2000s.

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