Rozprawy doktorskie na temat „Pacific Ocean”
Kliknij ten link, aby zobaczyć inne rodzaje publikacji na ten temat: Pacific Ocean.
Utwórz poprawne odniesienie w stylach APA, MLA, Chicago, Harvard i wielu innych
Sprawdź 50 najlepszych rozpraw doktorskich naukowych na temat „Pacific Ocean”.
Przycisk „Dodaj do bibliografii” jest dostępny obok każdej pracy w bibliografii. Użyj go – a my automatycznie utworzymy odniesienie bibliograficzne do wybranej pracy w stylu cytowania, którego potrzebujesz: APA, MLA, Harvard, Chicago, Vancouver itp.
Możesz również pobrać pełny tekst publikacji naukowej w formacie „.pdf” i przeczytać adnotację do pracy online, jeśli odpowiednie parametry są dostępne w metadanych.
Przeglądaj rozprawy doktorskie z różnych dziedzin i twórz odpowiednie bibliografie.
1
Coleman, John Edward. "Chemical studies of Pacific Ocean sponges". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ27122.pdf.
Pełny tekst źródła
2
Wade, Lowell. "The mineralogy and major element geochemistry of ferromanganese crusts and nodules from the northeastern equatorial Pacific Ocean". Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30427.
Pełny tekst źródłaStreszczenie:
A study of the mineralogy and major element geochemistry of ferromanganese crusts and nodules from the northeastern equatorial Pacific Ocean involved three inter-related projects: ft) the major element geochemistry of crusts and nodules from two study areas, (2) the development of a selective sequential extraction scheme (SSES) and a differential X-ray diffraction technique (DXRD) for the study of the mineralogy of the deposits, and (3) the application of the SSES and DXRD to a small population of crusts and nodules from the two study areas. The objectives of the first project were to relate the composition of the crust and nodule samples to the environment of formation as well as to the mineralogy which could be identified from a bulk powdered sample. The SSES was developed to determine the partitioning of Cu, Ni, and Co concentrations between the Mn and Fe oxides present in crusts and nodules. In developing a SSES, two goals had to be attained: (1) since crust and nodule samples are finite in size and numerous different analyses are to be preformed on a single sample, a SSES should be developed which uses as small amount of sample as feasible, and (2) develop a SSES which is as time efficient as possible. The development of the DXRD in conjuction with the SSES identified which Mn and Fe oxide mineral phase was responsible for hosting Cu, Ni, and Co. In developing the DXRD procedure two other goals had to be attained: (1) use of small leached samples, and (2) recovery of the sample aafter XRD analysis. The purpose of the third project was to test the two analytical procedures on a group of crust and nodule samples which have a wide range in compositions and oxide phase mineralogies.
One group of hydrothermal nodules, from Survey Region B, was found to be enriched in Mn and depleted in Fe and Si. The Mn-rich mineral phases were identified as todorokite and birnessite. The second group of hydrothermal nodules, from Survey Region B, was found to be enriched in Fe and Si and depleted in Mn. The Fe-Si rich mineral phase was identified as iron-rich nontronite. Both groups of hydrothermal nodules were depleted in Co, Cu, and Ni. Dymond et al. (1984) and Chen & Owen (1989) identified one group of hydrothermal nodules located close to the East Pacific Rise (EPR) as being enriched in Fe but depleted in Mn, Cu, Ni, and Co. This composition agrees with the Fe-Si rich hydrothermal nodules identified in Survey Region B. Both Dymond et al. (1984) and Chen & Owen (1989), however, interpreted a second group of nodules, close to the EPR, which were enriched in Mn but depleted in Cu, Ni, and Co as suboxic diagenetic deposits. This group of nodules is the Mn-rich end-member composition of hydrothermal nodules identifed in this study.
The composition of nodules from Survey Region B indicates there is a correlation between Co abundance and the proximity of the nodules to the hydrothermal discharge from the JEPR. Nodules that are Co-enriched are found farthest away from hydrothermal activity. In contrast, cobalt-depleted nodules coincide with known areas of hydrothermal activity.
The SSES and DXRD was applied to a small population of crusts and nodules from the two Survey Regions. The DXRD patterns from the second stage of leaching on the crusts and nodules showed that the iron phase mineralogy in marine crusts and nodules is either akaganeite or ferrihydrite. The DXRD patterns from the second stage of leaching on the Mn-rich hydrothermal crusts and nodules, from Survey Region B, identified the Mn-bearing mineral hausmannite.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
3
Wu, Pao-Kun. "Cloud effects on ocean mixed layer in the northeast Pacific Ocean". Thesis, Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/28030.
Pełny tekst źródłaStreszczenie:
This study was conducted to examine the effects of clouds on the ocean mixed layer, both short-term and seasonal. It utilized data collected at Ocean Station Papa in the northeast Pacific. Two numerical modeling simulations were performed (i.e., with variable cloud and with variable precipitation). The results for the variable cloud simulation indicated that the downward surface buoyancy flux and longer daylight period in summer may induce a significant albedo effect of cloud on ocean mixed layer. The upward surface buoyancy flux and longer night period in winter will result in a pronounced greenhouse effect of cloud on ocean mixed layer. The results of variable precipitation simulation showed that the mixed layer is most sensitive to precipitation between October and March. Model predictions are verified using data at Ocean Station Papa for monthly and yearly mean values of cloud cover and precipitation. The comparison between model prediction and observations shows that the mean values of observed MLD (H = 60.9 m) are much deeper than model-predicted values (H = 36.5 m)
4
Warmus, Katarzyna. "The form of the temperature-salinity relationship in the thermocline of the western Pacific Ocean". Thesis, The University of Sydney, 1988. https://hdl.handle.net/2123/26285.
Pełny tekst źródłaStreszczenie:
Conductivity/temperature/depth (CTD) data collected during the WESTROPAC’82 programme, are used to describe the temperature-salinity (TS-) relationship in the depth range of the Central Water. WESTROPAC’82 was carried out in September/October 1982 in the Western Pacific Ocean by the Division of Oceanography, Commonwealth Scientific and Industrial Research Organization (CSIRO).
The least squares method is applied to the CTD data to compare the observed shape of the TS—curve with shapes predicted from two models, the constant slope (SL) fit and the constant stability ratio (R) fit. The comparison is based on the test statistic at 5% level of significance. The structure of the main thermocline is revealed through analysis of the slope of the TS—curve and the stability parameter in 100 m depth increments.
The results show that over most of the WESTROPAC’82 region, the TS-curve is best described by a straight line suggesting that mixing is governed by turbulent vertical diffusion. Between 5°S and 10°S latitude the shape of the TS— curve is better described by the constant R fit, indicating prevalence of double-diffusive mixing as first proposed by Schmitt (1981). At the water mass boundaries located at latitude of 2°, 5°and 10°S, the thermocline is composed of layers of constant slope and constant R.
An artificial data set is used for the same analysis to test whether hydrographic bottle casts are suitable for objective comparison between ‘best-fit’ approximations of the TS-curves. The simulated hydrocasts are derived from the WESTROPAC’82 data set by selecting CTD information at 100 m depth increments between the salinity maximum and minimum.
The shape of the TS-curves determined from the CTD data is compared with that predicted from the artificial data to which a polynomial function had been fitted.
The best-fit approximations obtained from the original CTD and simulated bottle cast data are the same for 96 stations. At one station the two data sets produce difierent best fits, and at nine stations the artificial data are unable to discriminate between constant slope and constant R. All these stations are located near water mass boundaries.
The result indicates that a systematic survey of double diffusion activity in the ocean thermocline using hydrocasts from the World Oceanographic Data Centre is possible.
5
Dawe, Jordan Tyler. "Aspects of modeling the North Pacific Ocean /". Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/11015.
Pełny tekst źródłaStreszczenie:
Thesis (Ph. D.)--University of Washington, 2006.Vita. "A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves 94-101).
6
Wilson, Paul Alastair. "The evolution of Cretaceous Pacific Ocean guyots". Thesis, University of Cambridge, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363102.
Pełny tekst źródła
7
Yu, Xuri. "Dynamics of seasonal and interannual variability in the equatorial Pacific". Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/11065.
Pełny tekst źródła
8
Li, Tianshi. "Temporal variability of north Pacific Ocean surface cyclones". Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60060.
Pełny tekst źródłaStreszczenie:
The temporal variability of North Pacific Ocean surface cyclones is presented, based upon a nine cold-season dataset from the National Meteorological Center. Our results show that: (1) January is the most active month for oceanic cyclone activity; the most active zone of the cyclonic characteristics is at its southernmost location in January; (2) Interannual variability of cyclone activity is pronounced. The interannual variability of cyclone activity is predominantly stronger than the seasonal variability; (3) Analyses of objectively defined regimes, defined on the basis of a 30-day clustering of surface cyclone activity, reveal that regional climatological anomalies of surface cyclone frequency, significant at the 95% level of confidence, can be identified as precursors to the onset of these 30-day circulation regimes.
9
Hawco, Nicholas James. "The cobalt cycle in the tropical Pacific Ocean". Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/108907.
Pełny tekst źródłaStreszczenie:
Thesis: Ph. D., Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2017.Cataloged from PDF version of thesis.
Includes bibliographical references.
Although over a dozen elements are needed to support phytoplankton growth, only a few are considered to be growth-limiting. As the central atom in vitamin B12, cobalt is crucial for metabolism, but its status as a limiting nutrient is uncertain. This thesis investigates the geochemical controls on oceanic cobalt scarcity and their biological consequences. Analysis of over 1000 samples collected in the Tropical Pacific Ocean reveals a dissolved cobalt distribution that is strongly coupled to dissolved oxygen, with peak concentrations where oxygen is lowest. Large cobalt plumes within anoxic waters are maintained by three processes: 1) a cobalt supply from organic matter remineralization, 2) an amplified sedimentary source from oxygen-depleted coastlines, and 3) low-oxygen inhibition of manganese oxidation, which scavenges cobalt from the water column. Rates of scavenging are calculated from a global synthesis of recent GEOTRACES data and agree with cobalt accumulation rates in pelagic sediments. Because both sources and sinks are tied to the extent of oxygen minimum zones, oceanic cobalt inventories are likely dynamic on the span of decades. Despite extremely low cobalt in the South Pacific gyre, the cyanobacterium Prochlorococcus thrives. Minimum cobalt and iron requirements of a Prochlorococcus strain isolated from the Equatorial Pacific are quantified. Cobalt quotas are related to demand for ribonucleotide reductase and methionine synthase enzymes, which catalyze critical steps in DNA and protein biosynthesis, respectively. Compared to other cyanobacteria, a streamlined metal physiology makes Prochlorococcus susceptible to competitive inhibition of cobalt uptake by low levels of zinc. Although phytoplankton in the Equatorial Pacific are subject to chronic iron-limitation, widespread cobalt scarcity and vulnerability to zinc inhibition observed in culture imply that wild Prochlorococcus are not far from a cobalt-limitation threshold.
by Nicholas James Hawco.
Ph. D.
10
Steadley, Robert S. "Thermodynamic air/ocean feedback mechanisms in the equatorial Pacific". Thesis, Monterey, California. Naval Postgraduate School, 1992. http://hdl.handle.net/10945/24072.
Pełny tekst źródła
11
Banks, Helene Theresa. "Intrusions and mixing in the Western Equatorial Pacific Ocean". Thesis, University of Southampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243128.
Pełny tekst źródła
12
Kessler, William S. "Observations of long Rossby waves in the northern tropical Pacific /". Thesis, Connect to this title online; UW restricted, 1989. http://hdl.handle.net/1773/10971.
Pełny tekst źródła
13
Wang, Weimin. "The seasonal-interannual surface layer heat balance in the equatorial Pacific Ocean /". Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/11047.
Pełny tekst źródła
14
Anderson, Timothy A. "Visualization and assessment of Global Ocean Data assimulation experiment profile data for the Pacific Ocean". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2001. http://handle.dtic.mil/100.2/ADA395809.
Pełny tekst źródła
15
Mickett, John B. "Turbulent entrainment fluxes within the eastern Pacific warm pool /". Thesis, Connect to this title online; UW restricted, 2007. http://hdl.handle.net/1773/11005.
Pełny tekst źródła
16
Carr, Matthew Tobias. "Convective momentum transport over the tropical Pacific /". Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/10052.
Pełny tekst źródła
17
Ponte, Rui Vasques de Melo. "Observations and modelling of deep equatorial currents in the central Pacific". Thesis, Massachusetts Institute of Technology, 1988. http://hdl.handle.net/1721.1/58499.
Pełny tekst źródłaStreszczenie:
Thesis (Ph. D.)--Joint Program in Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 1988.Includes bibliographical references (leaves 178-180).
Analysis of vertical profiles of absolute horizontal velocity collected in January 1981, February 1982 and April 1982 in the central equatorial Pacific as part of the Pacific Equatorial Ocean Dynamics (PEQUOD) program, revealed two significant narrow band spectral peaks in the zonal velocity records, centered at vertical wavelengths of 560 and 350 stretched meters (sm). Both signals were present in all three cruises, but the 350 sm peak showed a more steady character in amplitude and a higher signal-to-noise ratio. In addition, its vertical scales corresponded to the scales of the conspicuous alternating flows generically called the equatorial deep jets in the past (the same terminology will be used here). Meridional velocity and vertical displacement spectra did not show any such energetic features. Energy in the 560 sm band roughly doubled between January 1981 and April 1982. Time lagged coherence results suggested upward phase propagation at time scales of about 4 years. East-west phase lines computed from zonally lagged coherences, tilted downward towards the west, implying westward phase propagation. Estimates of zonal wavelength (on the order of 10000 km) and period based on these coherence calculations, and the observed energy meridional structure at this vertical wavenumber band, seem consistent, within experimental errors, with the presence of a first meridional mode long Rossby wave packet, weakly modulated in the zonal direction. The equatorial deep jets, identified with the peak centered at 350 sm, are best defined as a finite narrow band process in vertical wavenumber (311-400 sm), accounting for only 20% of the total variance present in the broad band energetic background. At the jets wavenumber band, latitudinal energy scaling compared well with Kelvin wave theoretical values and a general tilt of phase lines downward towards the east yielded estimates of 10000-16000 km for the zonal wavelengths.
by Rui Vasques de Melo Ponte.
Ph.D.
18
Johnson, Gregory Conrad. "Near-equatorial deep circulation in the Indian and Pacific Oceans /". Thesis, Woods Hole, Mass. : Woods Hole Oceanographic Institution, 1990. http://hdl.handle.net/1912/2637.
Pełny tekst źródłaStreszczenie:
Thesis (Ph. D.)--Woods Hole Oceanographic Institution and Massachusetts Institute of Technology, 1990.Funding was provided by the Office of Naval Research and a Secretary of the Navy Graduate Fellowship in Oceanography. References : p. 117-121.
19
Cummins, Patrick F. "A quasi-geostrophic circulation model of the Northeast Pacific Ocean". Thesis, University of British Columbia, 1989. http://hdl.handle.net/2429/29082.
Pełny tekst źródłaStreszczenie:
A limited-area quasi-geostrophic numerical model with mesoscale resolution is developed to study the circulation in the Northeast Pacific Ocean. The model domain extends from the British Columbia/Alaska coast out to 170°W and down to 45°N, and incorporates the coastline geometry and bottom topography of the region.
In a benchmark experiment, the circulation is driven with a steady, climatological wind stress curl field. Statistical properties of the solution are determined from a long-term integration and compared with observations from the Gulf of Alaska. The cyclonic circulation of the model basin contains the analogue of a meandering Alaska Current. At the head of the Gulf, this current flows into an intense boundary current corresponding to the Alaskan Stream. Within the model Alaska Current, anticyclonic closed streamline features are occasionally generated which are representative of the Sitka Eddy, ln the upstream region, the model Alaskan Stream displays large amplitude aperiodic meanders, while, in the downstream region, the boundary current separates and is subject to smaller amplitude lateral meandering due to topographic waves. The occurrence of perturbations with similar characteristics in the Alaskan Stream has recently been verified in satellite AVHRR imagery.
The model is also used to examine the effects of bottom topography and seasonal wind forcing on the circulation of the subpolar gyre. The characteristics of the Alaskan Stream are shown to depend crucially on the presence of the Aleutian Trench. In an experiment with a flat bottom and steady forcing, the most energetic signal is due to mesoscale eddies with a 100 day period associated with barotropic wave propagation along the Aleutian arc. Bottom topography eliminates this signal by inhibiting the nonlinear transfer of energy between the first baroclinic and the barotropic mode, thereby stabilizing the model Alaskan Stream to baroclinic instability. Experiments with a climatological seasonal cycle in the wind field show that the bottom topography has an important influence in moderating the intensity of the seasonal response. This result is used to explain the discrepancy between observations of seasonal variability in the volume transport of the Alaskan Gyre and the transport obtained in previous numerical modelling studies.Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
Graduate
20
Varela, Diana Esther. "Nitrogenous nutrition of phytoplankton from the northeastern subarctic Pacific Ocean". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ27264.pdf.
Pełny tekst źródła
21
Bullock, Timothy A. (Timothy Augustine). "A diagnostic study of cyclogenesis in the western Pacific Ocean /". Thesis, McGill University, 1989. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59258.
Pełny tekst źródłaStreszczenie:
This study's goal is to quantify the influence of large-scale forcing on surface cyclogenesis. This is accomplished by considering seventy surface cyclones, whose maximum deepening occurs in the western North Pacific Ocean. Cyclone classification is based on this pressure change, ranging from +10 to $-$40 hPa/24 h. Composite surface, 850 and 500 hPa analyses for each class, constructed from NMC gridded data are used to diagnose quasi-geostrophic omega and frontogenetical forcing and static stability. Explosive cyclones are distinguished by strong downstream 850 and 500 hPa frontogenesis, suggesting deep baroclinicity's importance during the maximum deepening phase. Cyclogenesis, embedded in a deep, conditionally unstable environment increases with composite forcing. However, regression analyses, relating forcing and intensification, show explained variance to be generally small, owing to large case to case variability within classes. This variability is caused by exclusion of exponential surface vorticity enhancement and static stability effects, coarse-resolution data and analysis errors.
22
Sheridan, Timothy F. "Satellite precipitation analysis for a developing North Pacific Ocean cyclone". Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/23110.
Pełny tekst źródła
23
Kotilainen, Aarno Tapio. "Late Pliocene and Pleistocene sedimentation in the North Pacific Ocean". Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.621353.
Pełny tekst źródła
24
Rudorff, Natália de Moraes. "Ocean Colour Variability across the Southern Atlantic and Southeast Pacific". Instituto Nacional de Pesquisas Espaciais (INPE), 2013. http://urlib.net/sid.inpe.br/mtc-m19/2013/09.17.14.26.
Pełny tekst źródłaStreszczenie:
Ocean colour radiometry (OCR) provides essential information for studies of primary productivity, heat fluxes, and biogeochemical cycles in the upper ocean. Generalized OCR models relating satellite radiometric data to biogeochemical variables are developed using global in situ data sets. However, when applied to specific regions these models commonly give results with significant deviation from in situ measurements, mainly due to field and satellite measurement uncertainties and model underrepresentation of ocean colour variability. Hence to improve OCR products further understanding of the sources of measurement uncertainty and bio-optical variability across different oceanic regions is needed. This work was focused on the Southern Atlantic and Southeast Pacific Oceans encompassing important biogeochemical provinces with highly distinct optical waters. In situ data was collected during a summer campaign on board the research vessel Melville (MV1102 cruise). The first part of the investigation was an uncertainty analysis of the radiometric and bio-optical data with three main objectives: (i) test different radiometric techniques with above and in-water approaches (ii) apply closure analyses with forward modeling of remote sensing reflectance (Rrs); and (iii) analyze the impacts of the uncertainties on operational OCR models. The uncertainty analysis revealed moderate to high levels associated with the various techniques, with 12 to 26\% relative differences (RD) for the ocean-colour bands (412- 555 nm) and 3-12\% for the reflectance ratios (412-510/555). The use of a merged Rrs (Instruments, INS) reduced uncertainties since each individual technique was subject to different instrumental and environmental biases. Complete closure was not obtained, especially for the stations with more adverse environmental conditions (with winds, waves and clouds), with 18-34\% RD compared to modeled Rrs bands. Nonetheless, the impact of INS uncertainties on retrieved OCR products for empirical and semi-analytical (SA) models was still generally smaller than the intrinsic errors of the inversion schemes. Hence, the approaches applied to obtain more accurate measurements were effective in reducing the main sources of uncertainties. Significant sources of deviations of the OCR models were related to the optical variability of the study region and intrinsic model errors. The second part of the investigation analyzed the sources of bio-optical variability and their relations to biogeochemical variables across distinct provinces. The bulk inherent optical properties (IOPs) were in first order associated with the chlorophyll a concentration (Chla) gradient. Second order variations were explained by specific IOPs linked to the phytoplankton community structure, composition and size distribution of the particle assemblage and variability of the coloured dissolved and particulate organic matter (CDM). To synthetize the first and second order optical variations across the study region, a Regional Specific Optical Water Type (R-SOWT) classification was proposed by defining 5 classes that integrate the specific IOPs and bio-optical indices, i.e., a phytoplankton Size Index, CDM index, the specific backscattering coefficient (bbp/Chla) and spectral slope ($\eta$). The R-SOWT significantly improved the performance of SA models by using class-specific parameterizations, especially for the bbp retrieved by the GSM (Garver-Siegel-Maritorena) model, reducing from 35 to 9\% RP, and the CDM absorption coefficient of the QAA (Quasi-Analytical Algorithm) model, reducing from 30 to 23\% RD. For more optically complex waters the improvements of the retrievals were much more significant. Further analysis of spatiotemporal variations of the optical relations and applicability of the R-SOWT for different seasons (and regions) are recommended for future studies. This approach has potential to improve OCR satellite products and be used as a new product that integrates relevant information for biogeochemical studies.A radiometria da cor do oceano oferece informações essenciais para estudos de produtividade primária, fluxos de calor e ciclos biogeoquímicos na superfície dos oceanos. Modelos generalizados de cor do oceano que relacionam dados radiométricos de satélite com variáveis biogeoquímicos são desenvolvidos com bases de dados globais in situ. No entanto, quando aplicados a regiões específicas estes modelos apresentam desvios significativos que estão relacionados a incertezas nas medidas in situ e satelitais, e sub-representações da variabilidade da cor do oceano. Portanto, para a melhoria de produtos de cor do oceano é preciso conhecer melhor as fontes incertezas das medidas e a variabilidade bio-óptica em diferentes regiões oceânicas. O presente trabalho teve como foco os Oceanos Atlântico Sul Sub-tropical e Pacífico Sudeste abrangendo importantes províncias biogeográficas com águas opticamente distintas. Dados in situ foram coletados durante uma campanha de verão a bordo do navio de pesquisa R/V Melville (MV1102). A primeira parte do trabalho compreendeu análises de incertezas dos dados radiométricos e bio-ópticos com três objetivos principais: a) a comparação de diferentes técnicas de amostragem com instrumentos emersos e submersos; b) comparações com a reflectância de sensoriamento remoto (Rsr) modelada; e c) análises dos impactos das incertezas em modelos operacionais de cor do oceano. As análises de incertezas revelaram níveis de altos a moderados associados às diferentes técnicas, com diferenças relativas (DR) de 12 a 26\% para as bandas de cor do oceano (412-555 nm) e 3 a 12% para as razões de bandas (412-510/555). O uso de uma medida de Rsr integrada (Instrumentos, INS) reduziu as incertezas já que cada técnica individual estava sujeita a diferentes erros instrumentais e ambientais. O ajuste perfeito com a Rsr modelada não foi obtido, principalmente para as estações com condições ambientais mais adversidades (de vento, ondas e nuvens), com 18-34\% DR para as bandas espectrais. Ainda assim, o impacto das incertezas do INS foi de modo geral, menor que os erros intrínsecos aos modelos empíricos e semi-analíticos (SA) de cor do oceano. Dessa forma, os métodos empregados para obter medidas mais acuradas foram razoavelmente eficazes em reduzir as incertezas. Desvios significativos dos modelos de cor do oceano foram relacionados à variabilidade óptica da região de estudo e erros intrínsecos aos modelos. A segunda parte da investigação compreendeu análises das fontes de variabilidade bio-óptica e suas relações com as variáveis biogeoquímicas nas diferentes províncias. A distribuição dominante das propriedades ópticas inerentes (POIs) esteve associada ao gradiente de concentração de clorofila a (Cla). Variações de segunda ordem foram relacionadas a POIs específicas associadas à estrutura da comunidade fitoplanctônica, a composição e distribuição do tamanho das partículas e à variabilidade da matéria orgânica dissolvida e particulada (MODP). Para sintetizar as variações de primeira e segunda ordem na região de estudo, uma classificação Regional de Tipos Específicas de Águas Ópticas (R-TEAO) foi proposta para definir 5 classes, integrando as POIs específicas e índices bio-ópticos, i.e., o Índice de tamanho do fitoplâncton, índice de CDM, o coeficiente especifico de retroespalhamento das partículas (bbp/Cla) e o parâmetro de variação espectral ($\eta$). O R-TEAO melhorou significativamente o desempenho de modelos SA com parametrizações especificas para cada classe, reduzindo a DR do bbp do modelo GSM01 (Garver-Siegel-Maritorena) de 35 a 9\% e o coeficiente de absorção do MODP de 30 a 23\% para o modelo QAAv5 (Quase Analytical Algorithm). Para águas mais opticamente complexas a melhoria dos modelos foi ainda mais significativa. Análises das variações espaço-temporais das relações ópticas e a aplicabilidade do R-TEAO para estações sazonais diferentes e outras regiões oceânicas, são recomendadas para pesquisas futuras. O método tem potencial de ser aplicado para a melhoria de produtos de cor do oceano por satélite e ser usado como um novo produto integrando informações importantes para estudos biogeoquímica.
25
Prabhakar, Gouri. "Characteristics of Regional Aerosols: Southern Arizona and Eastern Pacific Ocean". Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/332834.
Pełny tekst źródłaStreszczenie:
Atmospheric aerosols impact the quality of our life in many direct and indirect ways. Inhalation of aerosols can have harmful effects on human health. Aerosols also have climatic impacts by absorbing or scattering solar radiation, or more indirectly through their interactions with clouds. Despite a better understanding of several relevant aerosol properties and processes in the past years, they remain the largest uncertainty in the estimate of global radiative forcing. The uncertainties arise because although aerosols are ubiquitous in the Earth's atmosphere they are highly variable in space, time and their physicochemical properties. This makes in-situ measurements of aerosols vital in our effort towards reducing uncertainties in the estimate of global radiative forcing due to aerosols. This study is an effort to characterize atmospheric aerosols at a regional scale, in southern Arizona and eastern Pacific Ocean, based on ground and airborne observations of aerosols. Metals and metalloids in particles with aerodynamic diameter (Dp) smaller than 2.5μm are found to be ubiquitous in southern Arizona. The major sources of the elements considered in the study are identified to be crustal dust, smelting/mining activities and fuel combustion. The spatial and temporal variability in the mass concentrations of these elements depend both on the source strength and meteorological conditions. Aircraft measurements of aerosol and cloud properties collected during various field campaigns over the eastern Pacific Ocean are used to study the sources of nitrate in stratocumulus cloud water and the relevant processes. The major sources of nitrate in cloud water in the region are emissions from ships and wildfires. Different pathways for nitrate to enter cloud water and the role of meteorology in these processes are examined. Observations of microphysical properties of ambient aerosols in ship plumes are examined. The study shows that there is an enhancement in the number concentration of giant cloud condensation nuclei (Dp>2 μm) in ship plumes relative to the unperturbed background regions over the ocean.
26
Hurwitz, Bonnie Louise. "Viral Community Dynamics and Functional Specialization in the Pacific Ocean". Diss., The University of Arizona, 2012. http://hdl.handle.net/10150/265369.
Pełny tekst źródłaStreszczenie:
Viruses are the most abundant biological entity on Earth and outnumber their hosts ten-to-one. Ocean viruses (phages) impact bacterial-driven global biogeochemical cycles through lysis, manipulating host metabolism, and horizontal gene transfer. However, knowledge of virus-host interactions and viral roles in ecosystems remains limited due to few cultured marine phage genomes and non-quantitative culture-independent metagenomes. Here, I develop and apply novel and well-tested bioinformatic techniques to explore Pacific Ocean viral communities using quantitative datasets derived from rigorously-tested preparation methods. To evaluate concentration and purification methods, I examined triplicate metagenomes from a single ocean sample using four protocols. Concentration protocols showed statistical differences in taxonomy whereas purification protocols did not. Specifically, TFF-concentrated metagenomes contained trace bacterial contamination and had fewer abundant taxa as compared to FeCl₃-precipitated metagenomes. K-mer analysis using the complete dataset revealed polymerase choice defined access to "rare" sequences.To explore unknown viral sequences, I organized known and unknown sequence space into 27K high-confidence protein clusters (PCs) from 32 diverse Pacific Ocean Virus (POV) metagenomes, which doubled available PCs and included the first pelagic deep-sea viral metagenomes. Using PCs as a whole-viral-community diversity metric revealed decreases from coastal to open ocean, winter to summer, and deep to surface, that correlate with data from microbial genetic diversity markers (no parallel viral markers exist).Biologically, POV metagenomes showed that viruses likely reprogram central metabolic pathways in microbial communities far beyond the "photosynthesis viruses" paradigm. Gene distribution patterns from 35 viral gene families (31 new) revealed niche-specific (photic vs aphotic zone) altered pathway carbon flux presumably optimized to best locally generate energy and drive viral replication. Further, these PCs define the first "core" (180 genes) and "flexible" (423K genes total) viral community genome. Functionally, core genes again suggest niche-differentation with extensive Fe-S cluster-related genes for electron transport and metabolic enzyme catalysis in photic samples, and manipulation of host pressure-sensitive genes in aphotic samples. Taxonomically, these data deconstruct the culture-based paradigm that tailed viruses dominate in the wild - instead they appear ubiquitous, but not abundant.
27
Young, Carina Saxton. "Decadal variability of the Pacific subtropical cells and equatorial sea surface temperature". Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31671.
Pełny tekst źródłaStreszczenie:
Thesis (M. S.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2010.Committee Chair: Di Lorenzo, Emanuele; Committee Member: Bracco, Annalisa; Committee Member: Lynch-Stieglitz, Jean. Part of the SMARTech Electronic Thesis and Dissertation Collection.
28
Heck, Amy D. "Air-ocean characteristics during the Impact of Typhoons On The Ocean In The Pacific (ITOP) Program". Thesis, Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/5581.
Pełny tekst źródłaStreszczenie:
Approved for public release; distribution is unlimited.Interactions between a tropical cyclone (TC) and the underlying ocean environment can have significant impacts on physical mechanisms during the formation and intensification of the storm. During the summer of 2010, the Impact of Typhoons on the Ocean in the Pacific (ITOP) program was conducted to examine interactions between the ocean and TCs using a variety of experimental approaches. Specific observational assets included an array of moored buoys, two WC-130J aircraft, and a U.S. research vessel (RV Revelle). Airborne-deployed sensors included dropwindsondes, airborne expendable bathythermographs (AXBTs), Lagrangian floats, and drifters. In this thesis, AXBT observations were used to examine basic characteristics of the ocean environment during TCs that occurred during ITOP. Observations were compared to the Naval Research Laboratory East Asian Seas Nowcast Forecast System (NRL EASNS). For high ocean heat content (OHC), the model analyzed OHC was too low and for low OHC, the model analyses were too high. The largest analyzed and observed differences were found to occur in regions of TC-induced ocean changes. The significance of this comparison is the contribution to understanding the relationship between OHC and TC structure, with specific focus on the representation in the operational NRL EASNFS.
29
Ries, Harry J. "The climatological seasonal response of the ocean mixed layer in the equatorial and tropical Pacific Ocean". Thesis, Monterey, California. Naval Postgraduate School, 1988. http://hdl.handle.net/10945/22945.
Pełny tekst źródłaStreszczenie:
Seasonal changes of mixed layer depth (MLD) can be related to the forcing by the net surface heating and wind speed. This is shown in this study by comparing the monthly mixed layer depth from temperature profiles in the Bauer-Robinson Numerical Atlas with monthly net surface heating and wind speed obtained from the Weare Marine Climatic Atlas of the Tropical Pacific Ocean. Using a conceptual model based on mixed layer physics, ocean response and atmospheric forcing are examined using the Obukhov mixing length. A pattern in the seasonal variation of upwelling along the Equator is also examined. The model links the atmospheric and oceanic climatologies through the derived MLD (oceanic data) and Obukhov mixing lengths (forcing data). The results show a high degree of pattern similarity between the seasonal response of the ocean and the seasonal changes in atmospheric forcing. The pattern of seasonal influence on MLD at the Equator is very weak in comparison to that of the tropics and sub-tropics. Keywords: Ocean models; Atmosphere models; Equatorial regions; Mixed layer marine; Air water interactions; Theses. (EDC)
30
Pezzi, Luciano Ponzi. "Equatorial Pacific dynamics : lateral mixing and tropical instability waves". Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.274585.
Pełny tekst źródła
31
Bograd, Steven J. "Lagrangian observations of the near-surface circulation in the North Pacific, 1990-1995". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0008/NQ34514.pdf.
Pełny tekst źródła
32
Helber, Robert William. "Upper ocean upwelling, temperature, and zonal momentum analyses in the western equatorail [sic] Pacific". [Tampa, Fla. : s.n.], 2003. http://purl.fcla.edu/fcla/etd/SFE0000073.
Pełny tekst źródła
33
Charters, Jeffrey William. "Biogeochemistry of Pb in the Northeastern subarctic Pacific Ocean and the Beaufort Sea of the Arctic Ocean". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43257.
Pełny tekst źródłaStreszczenie:
Using a method which simultaneously concentrates and isolates Pb from seawater, a total of 208 samples
collected using trace-metal clean techniques were determined for dissolved Pb concentration in the subarctic
Northeast Pacific and the Canada Basin of the southwestern Arctic Ocean. The analytical method found good
agreement between determined values and consensus values of several seawater standards. Concentration in
seawater was generally dictated by proximity to pollution sources which appeared to provide Pb via aeolian
deposition and by proximity to primary productivity or freshly precipitated mineral phases which scavenged Pb
to lower levels than expected based on previous research. Over the entire dataset, concentration ranged from 1.8
pmol/kg to 81.3 pmol/kg, with the highest values occurring just below the permanent mixed layer in the
northeast Pacific and was of unknown origin. The lowest level was found in the Pacific water mass of the
southern Beaufort Sea, which may be the result of interactions with sediment during transit through the Bering
and Chukchi Seas. When samples that were expected to be contaminated are discounted, Pb levels were
generally lowest in the Arctic, below 30 pmol/kg. Samples taken from three eddies along the British Columbian
and southern Alaskan coasts found low [Pb] within the eddy relative to reference stations, though in two of the
eddies a phytoplankton bloom had not occurred, suggesting that either the source water was low in Pb or
scavenging had occurred by sorption onto precipitated mineral phases during estuarine processes. A low-
resolution time series between 1992 and 2010 at Ocean Station Papa (OSP; 50°N, 145°W) found that Pb
concentration at this location has remained quite steady over time, in contrast with the North Atlantic Ocean
which showed a drastic decrease in concentration over the same time period. The difference may be attributed to
formation of the water mass in the Sea of Okhotsk during the winter when atmospheric conditions would
transport most Asian pollution away from the region where the water mass subducts and advects towards OSP,
along with a different history of Pb pollution upwind of the Atlantic and Pacific Oceans.
34
Davis, Michael A. "Cloud-Radiative Feedback and Ocean-Atmosphere Feedback In the Southeast Pacific Ocean Simulated by IPCC AR4 GCMs". The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1313350254.
Pełny tekst źródła
35
Schroeder, Robert E. "The ecology of patch reef fishes in a subtropical Pacific atoll: recruitment variability, community structure and effects of fishing predators". Thesis, University of Hawaii at Manoa, 1989. http://hdl.handle.net/10125/18158.
Pełny tekst źródłaStreszczenie:
The ecology of patch reef fishes was studied to quantify the main
factors that affect the natural variability of the fish community and
to determine the effects produced on the community by experimental
removal of predators. Initially, a year-long baseline description was
completed of the physical, biological and ecological characteristics of
8 pristine patch reefs at Midway lagoon. For over 3 subsequent years,
piscivorous predators were spearfished at least monthly, often for days
at a time, on 4 of the 8 reefs. Fish populations were visually
censused throughout the experiment. In all seasons and years of the
project, daily recruitment rate of postlarval fishes to natural patch
reefs was compared to that measured on standardized, artificial reefs
of various sizes and degrees of inter-reef isolation. Finally, all
baseline measurements were replicated and complete collections were
made of all fishes, to validate the visual census method.
Visual censusing was found to be of adequate precision and accuracy
for most resident, non-cryptic species (highest for small patch reefs).
Fishes could be assigned to size classes underwater by visual estimate
with high accuracy. Rotenone collections were highly effective in
quantifying many species commonly missed or underestimated in visual
censuses.
Only a few species composed the bulk of all recruits, while most
species were rare or not seen at all. Variation between species was
related to life history strategies or behavioral requirements. High temporal variability was found at the following scales: 1) Annuallywhere
variability increased with the magnitude of recruitment, and
different species recruited heavily in different years, suggesting that
species specific factors in the plankton are more important than
general oceanographic conditions; 2) Seasonally- pulsing strongly in
summer, and occasionally late fall, when favorable environmental
conditions may maximize growth and survival; and 3) Daily- with 1 or 2
strong peaks (each only a few days long) over a period of several weeks
of low, variable recruitment.
Small-scale spatial variability between replicate attractors
(standardized artificial reefs) and between attractor types (coral and
wire) were both high for a few species recruiting abundantly, although
most recruits are probably substrate generalists. Rigorous visual fish
censuses can adequately document moderate- to long-term temporal
variation in the abundances of recently recruited juveniles on patch
reefs (i.e., based on similar temporal patterns assessed by daily
attractors). Daily total recruitment rate increased, although at
diminishing densities, with (attractor) reef size, and with degree of
inter-reef isolation. Abundances of recently recruited fish censused
on neighboring, natural patch reefs (much larger than attractors)
increased with reef size. The effect of isolation on these natural
reefs was confounded by the stronger effect of reef size. These
results suggest that if optimum size and spacing of reefs is provided,
either by proper design of artificial reefs or selection of marine reserves, managers may enhance fish recruitment and ultimately improve
local fisheries:
Of the 135 fishes censused on the patch reefs studied, only 6
species together accounted for 70% of the total number of all fish,
mainly due to heavy seasonal recruitment pulses. Strong seasonal and
annual variability in recruitment was responsible for most of the
temporal variation in fish abundance. The structure of patch reef fish
communities at Midway was characterized by high unpredictability (e.g.,
great seasonal and/or annual variability in recruitment by common
species, recruitment limitation for most species, and a high turnover
rate detected by frequent sampling). Some predictions of the theory of
island biogeography were also met by these fish communities (e.g.,
species richness correlated strongly with patch reef area, volume and
relief). and total fish abundance. Some populations also exhibited a
degree of long-term stability. Species diversity [H'] was similar
among different size reefs.
The experimental fishing on piscivores produced a catch composed
mainly of lizardfish, due largely to immigration following the removal
of other, competitively superior, highly resident piscivores.
Scorpionfish and moray eels were also dominant predators. The expected
decreases in catch-per-unit-effort were not realized, except for a
quantitatively insignificant family (hawkfish). Conversely, the catch
of the highly migratory lizardfish actually increased as fishing
progressed. Changes in the catch composition for other piscivores related mainly to major changes in reef size or to patterns of large,
inter-year recruitment fluctuations. Census data confirmed the major
trends indicted by catch results. Sharks and jacks were attracted to
the experimental reefs by spearfishing; the study was unable to
determine whether their piscivorous effect was different between reef
treatments.
Patch reef fish communities at Midway were relatively resilient to
long-term, intense fishing pressure on piscivores. However, enhanced
survival of a large, annual, summer recruitment pulse of a common
cardinalfish, synchronized with a temporary but significant reduction
of lizardfish (the most prevalent piscivore) by fishing, suggested that
an effect of predation on reef fish populations is experimentally
detectable and considerable. However, temporal and spatial variability
in recruitment, and reef size differences and changes in size were the
primary factors responsible for the observed temporal patterns in fish
abundance. COlnmunity analysis involves numerous confounding effects
and requires the most careful interpretation for valid conclusions.xvi, 321 leaves, bound : ill. ; 29 cm.
36
Katzman, Rafael. "Structure and dynamics of the Pacific upper mantle /". Woods Hole, Mass. : Massachusetts Institute of Technology, Woods Hole Oceanographic Institution, Joint Program in Oceanography/Applied Ocean Science Engineering, 1998. http://hdl.handle.net/1912/1834.
Pełny tekst źródłaStreszczenie:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1998."February 1998." "Doctoral dissertation." Includes bibliographical references (p. 189-198).
37
Bahr, Frederick L. "The effects of rainfall on temperature and salinity in the surface layer of the equatorial Pacific". Thesis, 1991. http://hdl.handle.net/1957/27797.
Pełny tekst źródłaStreszczenie:
Measurements of temperature and salinity in the upper 5 m of the ocean
along the equator showed cool fresh anomalies due to rain showers. The
measurements were made between 140 W and 110 W during April 1987, an
El Nino year. The eastern equatorial Pacific was characterized by weak winds
(3 m/s average), high rainfall (1.6 cm/day), and warm surface temperatures
(28.4 C). Measurements of temperature were made from a catamaran float
at 0.5 and 1 m depth and at 5 m depth from the ship. Salinity was measured
at a depth of 1 m from the float and 5 m from the ship. The float was towed
off of the port side of the ship outside of the bow wake. Near-surface low
temperature and low salinity anomalies due to cool rainfall were encountered.
These anomalies were on average cool and fresh by 0.02 C and 0.2 PSTJ
with maximum values of 0.5 C and 1.6 PSU. The horizontal extent of the
anomalies ranged from less than 10 to more than 100 km. Rainfall depths
estimated from salt conservation agreed roughly with shipboard rain-gauge
measurements. The characteristic lifetime of the anomalies, estimated from
the ratio of the average rain depth to average rain rate, was about 10 hrs.
Rainfall temperatures were computed from the T-S mixing curves for three
large, newly-formed anomalies. The average rainfall temperature was 21 C.
Ocean buoyancy fluxes estimated for intense rain showers were an order of
magnitude larger than the fluxes in the absence of rain.Graduation date: 1992
Best scan available for p.15-16, 35. Original is a black and white photocopy.
38
Batchelder, Harold Parker. "Population dynamics and feeding ecology of the copepod, Metridia pacifica, in the subarctic Pacific Ocean". Thesis, 1985. http://hdl.handle.net/1957/27781.
Pełny tekst źródła
39
Hsu, Yu-Chen, i 許友貞. "Relationship of SST between Tropical Pacific Ocean and Southwest Atlantic Ocean". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/ypusq5.
Pełny tekst źródłaStreszczenie:
博士國立中山大學
海洋環境及工程學系研究所
107
In the subpolar region in the southern hemisphere, the Antarctic Circumpolar Current (ACC) is one of the main sources of the Peru Current. The ACC plays an important role in the climate change of the world. The fluctuations in the ACC intensity of the western South Atlantic Ocean consequentially influence the SST (Sea Surface Temperature) and marine ecosystems. However, the variations in the SST in the Southern Ocean have rarely been addressed. It is because the South Atlantic Ocean is rarely sampled and studied tied to its inclement weather and rigorous environment in the area. FFT, Wavelet, Empirical Orthogonal Function (EOF), Ensemble Empirical Mode Decomposition (EEMD), Harmonic analysis, Cross-Correlation Analysis (Xcorr) and low pass filter methods are applied to a 147-year (1870-2016) time series dataset of SST distributed by the Met Office Hadley Centre. We find that there are the obvious inter-annual and inter-decadal variations existing in our study area. The results show that SSTAs in the oceans west and east of the South America and Antarctic Peninsula have respectively strong positive (R = 0.56) and negative (R = −0.67) correlations with the Niño 3.4 SSTA. We further show that, statistically, the temporal variations in the SSTAs of the ACC lead the Niño 3.4 SSTA by four to six months. Such findings imply that change in the strength of El Niño-Southern Oscillation (ENSO) or circulation under the changing climate could change the climate in regions at higher latitudes as well. EOF analyses show the particularly negative correlations (R=-0.56) with Pacific Decadal Oscillation (PDO) periods. This study further showed that changes in SSTAs in the regions mentioned above were enlarged when the PDO and the ENSO were in the same warm or cold phase, implying that changes in the SST of higher latitude oceans could be enhanced when the influence of the ENSO is considered along with the PDO. Furthermore, we analyzed the cross-correlation between the Brazil-Malvinas Confluence Zone (BMC) and PDO indexes. The result showed that the BMC index had a strong positive correlation (R=0.75) with the PDO index, when the PDO index time series led by 3 to 4 years of the BMC index time series. Such a duration was similar to the periodicity of a typical ENSO event, implying that variations in BMC index might reflect both the ENSO and PDO events.
40
Masina, Simona. "Tropical instability waves in the Pacific Ocean". 1996. http://catalog.hathitrust.org/api/volumes/oclc/38280465.html.
Pełny tekst źródła
41
Ho, Yao-Kuang, i 何燿光. "The Maritime Order of Western Pacific Ocean". Thesis, 2008. http://ndltd.ncl.edu.tw/handle/36z4y3.
Pełny tekst źródła
42
Lou, J. "South Pacific Ocean climate dynamics and predictability". Thesis, 2021. https://eprints.utas.edu.au/39006/1/Lou_whole_thesis_ex_pub_mat.pdf.
Pełny tekst źródłaStreszczenie:
The mechanisms and predictability of Pacific decadal climate variability (PDV) is an active area of research in climate science and is one of high societal importance. To date, most research into PDV has been focused on mechanisms and responses in the North Pacific. This thesis presents a comprehensive investigation, based on the development and application of a family of hierarchical stochastically forced models, of the mechanisms underpinning PDV climate predictability and that focuses on the role of the South Pacific Ocean and coupling to the tropics.
First, a simple one-dimensional first-order autoregressive (AR1) model was used to understand the space and time variations of the South Pacific decadal oscillation (SPDO) – which represents the leading sea surface temperature (SST) mode in the South Pacific. The analysis revealed that the first Pacific-South American (PSA1) pattern is the key atmospheric driver of the SPDO. Further, the leading mode of integrated subsurface upper ocean temperature variability was shown to match expectations from the propagation of oceanic Rossby waves across the extratropical South Pacific, with the atmospheric PSA variability providing the high-frequency ‘noise’ source of the observed low-frequency (‘reddened’) SST SPDO response.
Second, the stochastically forced AR1 model was generalised to higher-dimensional fields with the inclusion of spatial features using a linear inverse model (LIM) approach. The deterministic dynamics underpinning the combined tropical and South Pacific system was investigated, with the seasonal predictive skill of the SPDO and El Niño–Southern Oscillation (ENSO) quantified under the LIM framework. It was found that, although the oscillatory periods of ENSO and the SPDO are distinct – the former oscillating on interannual timescales and the latter oscillating on (inter-)decadal timescales – their damping time scales were very similar, and their predictive skill comparable. With the inclusion of subsurface processes in the extratropical South Pacific, the linear predictive skill of both ENSO and the SPDO was found to be enhanced. Overall, the study showed that Pacific SST variability forecast skill from the computationally cheap LIMs was competitive with state-of-the-art operational seasonal forecast systems that employ sophisticated initialisation schemes and general circulation models, thus providing a useful benchmark for these operational systems.
Third, the LIM framework was applied to gain a deeper understanding of the role of stochastic forcing from the atmospheric PSA variability and to determine the optimal structures for initialised forecasts of the tropical and South Pacific climate system and its variability. This analysis revealed the spatial imprint of atmospheric PSA variability combined with temporal stochastic forcing that acts to drive the low frequency oceanic SST variability across the tropical and South Pacific, and excites optimal initial perturbations for the prediction of ENSO and the SPDO.
Finally, informed by the aforementioned hierarchy of stochastically forced linear reduced space models, the thesis culminates with an overarching framework that links the atmosphere to the surface and subsurface oceans across a range of time scales from (intra-)seasonal to (inter-)decadal. Hence, the thesis provides, for the first time, a mechanistic framework and integrated understanding of the drivers of large-scale South Pacific climate variability and predictability.
43
Wang, Chih-chia, i 王志嘉. "Pacific ocean, India ocean, Mediterranean Sea, and Atlantic Ocean atmospheric air CO2 observation and analysis". Thesis, 2011. http://ndltd.ncl.edu.tw/handle/44424686587651549254.
Pełny tekst źródłaStreszczenie:
碩士國立中央大學
大氣物理研究所
99
The result for global greenhouse gas is from industrialization in IPCC AR4, CO2 is the most greenhouse gas (GHG) radiative forcing of climate between 1750 and 2005. Wanninkhof [1992] analysis global sea uptake CO2 is 2.2(+22% between -19%)Pg C per year. Ocean occupied the earth surface 70%, but the ocean surface air CO2 is too sparse, so we have use island CO2 observation data or program project vessel observation. Global CO2 observations have four type: 1. Ground observation: The ground base stations in the WDCCG (World Data Centre for Greenhouse Gases) have to map out; it includes ship observation, aircraft observation, and ground based observation; 2. Aircraft observation : MOZAIC has been from 1993A.D. based on EU and Boeing Company suggestion, it is major in observation O3, H2O, CO, and NOx, CARIBIC is suggest in germen airline from 1997 A.D., it major in greenhouse gas and aerosols. IAGOS had been 2006 A.D. combine MOZAIC and CARIBIC; CONTRAIL had been star from 1993 A.D, major in CO2 and CH4; 3. Satellite observation: Envisat, Europe satellite takes with CIAMACHY, MIPAS, and GOMOS. AQUA, US takes with AIRS to observation CO2, GOSAT, Japan, major observation CO2;4. Program project vessels observation, and PGGM : program project vessels observation include WOCE Program、 CLIVAR/WHPO Program、 Global Volunteer Observing Ship (VOS) Program、 Global Coastal Program Data、CARINA 、PACIFic ocean Interior CArbon (PACIFICA). PGGM (Pacific greenhouse gas measurment project) star form 2009A.D., it major in Pacific ocean, India ocean, Mediterranean Sea, and Atlantic Ocean surface sea air CO2. In our data, i use datas has been start form 2010/Jan/29 to 2011/Mar/20, it have 46 routes. First, we start from data quality control, no use 1 gas bottle, second split data to global 2.5 X 2.5 degreed. Figure out time series with Mauna loa station and other station in WDCGG. Gridded data compare with land datas, it have same carbon seasonal change, and there different in two data is less than 10~20 PPM, it shows ship observation datas has catch the carbon seasonal change.
44
Robertson, Angela K. "EASTERN EQUATORIAL PACIFIC PRODUCTIVITY VIA TWO GEOCHEMICAL PROXIES". Thesis, 2012. http://hdl.handle.net/1805/2740.
Pełny tekst źródłaStreszczenie:
Indiana University-Purdue University Indianapolis (IUPUI)Drivers that influence oceanic productivity are not clearly constrained. However, sea level changes during glacial cycles have been proposed as a potential driver for productivity variations observed over warm and cold climate periods. In order to determine this, additional oceanic paleoproductivity data collection is necessary to estimate the ocean’s feedback in response to a dynamic climate. The eastern equatorial Pacific (EEP) is an ideal site for productivity studies due to its high levels of nutrients and deep upwelling. This research examines the phosphorous and barite geochemisty of four EEP sites while also comparing the sites’ glacial and interglacial productivity variations to the geochemistry and productivity results of an independent central equatorial pacific site. Phosphorus and other elemental data were collected from sites 845, 848, 849, and 853 (ODP Leg 138). Using a Ba/Ti and P/Ti proxy (“excess” proxies), distinct productivity variations during glacial and interglacial periods were observed. While the age model for these sites has been estimated, the observed variations more than likely agree with high productivity during glacial periods and lower productivity during interglacial periods. Central equatorial Pacific cores RR0603-03TC and RR0603-03JC (IODP site survey cruise for Proposal 626) have been used as a reference for geochemical concentration parameters, as well as a comparison tool for productivity variations among the central and eastern sites. The central equatorial geochemistry results provided support for sea level changes driving paleoproductivity variations. The similar variation patterns displayed by the EEP’s geochemical data in this research could provide additional support for this hypothesis.
45
Brown, Glenn R. "Tectonic, sedimentary, and volcanic processes associated with rifting of the central Bonin island arc". Thesis, 1991. http://hdl.handle.net/10125/9840.
Pełny tekst źródła
46
Marsters, Janice Christine. "The influence of microfossil content on the physical properties of calcareous sediments from the Ontong Java Plateau". Thesis, 1995. http://hdl.handle.net/10125/9864.
Pełny tekst źródła
47
Leonardi, Alan P. "Interannual variability in the Eastern subtropical Pacific Ocean". 2000. http://catalog.hathitrust.org/api/volumes/oclc/50069828.html.
Pełny tekst źródła
48
Enriquez, Kelly D. "Three-dimensional gravity analysis of the Pacific-Antarctic east Pacific rise at 36.5°S, 49.8°S and 54.2°S". Thesis, 1994. http://hdl.handle.net/1957/29143.
Pełny tekst źródłaStreszczenie:
Three-dimensional gravity analysis is the process of removing the predictable
components from the free-air gravity anomalies and has proven to be useful for
interpreting the subsurface structures and active processes at mid-ocean ridges. The
three-dimensional effects of the seafloor and Moho topography, assuming a constant
crustal thickness and constant crust and upper mantle densities, are subtracted from the
free-air anomalies, yielding the mantle Bouguer anomalies. Mantle Bouguer anomalies
at mid-ocean ridges are believed to be largely due to the three-dimensional thermal
structure, which can be predicted using a simple passive flow model. When the gravity
contribution from the predicted thermal structure is removed from the mantle Bouguer
anomalies, the residual mantle Bouguer anomalies are created, which represent lateral
variations in the crustal thickness and/or density variations from the assumed model.
Three-dimensional gravity analysis has been carried out over three areas along
the Pacific-Antarctic East Pacific Rise (EPR): (1) the eastern intersection of the Menard
transform with the EPR, (2) the overlapping spreading center (OSC) at 36.5°S and, (3)
the western intersection of the Raitt transform with the EPR. This geophysical analysis
provides an essential tool for understanding the subsurface crustal/upper mantle structure of the fast spreading EPR, and more specifically at transform and nontransform offsets along the EPR.
Several interesting features were observed at the eastern intersection between the
Menard transform and the EPR. The continuous nature of the residual mantle Bouguer
anomalies along the ridge axis suggests that the 60 km of ridge axis surveyed here has a
fairly uniform crustal/upper mantle structure. Significant features are not observed in
the residual mantle Bouguer anomalies at the ridge-transform intersection or along the
eastern 75 km of the Menard transform. At the ridge-transform intersection, fresh lavas
from the observed overshot ridge have filled in the transform valley and have
subsequently thickened the crust, eliminating any crustal thinning that is occurring there.
The large OSC at 36.5°S has a left-stepping offset of approximately 34 km. The
most significant feature in the gravity data from this study area is the observed low in
the mantle Bouguer anomalies which extends from the northern ridge segment, eastward
to the "inactive" rift and continued along the southern ridge segment. This gravity low
suggests that this region is underlain by thicker crust and/or hotter, less dense material.
No significant features are observed in the residual mantle Bouguer anomalies
associated with the overlap basin or the two smaller basins that border the "inactive" rift.
The western ridge-transform intersection (RTI) between the Raitt transform and
the EPR significantly differs from the Menard transform study area. A transform valley
is not observed at this RYE and neither is an overshot ridge. Instead, a transformparallel
median ridge is observed east of the RTI, and a fossil transform valley is
observed north of the RTI. A low in the residual mantle Bouguer anomalies is
associated with the fossil transform valley and the median ridge, suggesting that these
areas are underlain by thicker crust and/or less dense material. Positive residual mantle
Bouguer anomalies observed at the inside corner of the RYE suggest that this area is
underlain by thinner crust and/or colder, more dense material; while at the outside corner of the ridge-transform intersection, a residual anomaly low is observed which suggests
that the outside corner is underlain with thicker crust and/or hotter, less dense material.Graduation date: 1995
Figures in original document are black and white photocopies. Best scan available.
49
Ellis, Steven G. "Seasonal dynamics and allometric considerations of feeding and food processing for macrozooplankton in the northeast Pacific Ocean". Thesis, 1991. http://hdl.handle.net/1957/27738.
Pełny tekst źródła
50
Greiser, Christine M. "Surface heat flux estimates from NCAR electra data over the pacific warm pool during TOGA COARE". Thesis, 2002. http://hdl.handle.net/1957/28573.
Pełny tekst źródłaStreszczenie:
The warm pool region of the western tropical Pacific is of particular interest to
atmospheric dynamics because it represents a significant source of energy to the
atmosphere. A better understanding of heat transfer driven by mesoscale and
turbulent circulations within this region could lead to improved global circulation
models, and therefore to improved prediction of global weather patterns. A first step
to this understanding is to evaluate empirical data as well as the methods used to
estimate heat transfer, or heat flux, at the surface. Of specific interest here are latent
heat flux, the heat transfer associated with evaporation, and sensible heat flux, the heat
transfer associated with convection and conduction. In this paper, two different
methods of turbulent flux calculation, eddy correlation and the bulk aerodynamic
method are compared. Eddy correlation directly uses turbulence measurements to
estimate heat flux whereas the bulk aerodynamic method relies on similarity theory to
relate heat flux to mean flow quantities. A brief discussion of selection of averaging
length based on flight altitude is included, as well as a comparison of errors introduced
in averaging velocity as a scalar or as a vector. Errors introduced by averaging,
including mesoscale flux enhancement, are evaluated for strong and weak wind cases
during relatively light convection in the region. Finally, month to month variability in
heat flux is evaluated in an effort to further understand the accuracy of various
approximations used in flux calculation.Graduation date: 2002