In between the Oceans and the Earth (The cities by Oceans) Projects in between the oceans and the earth For studies of towns on the seashores in magister studies under leadership of Ing. Arch Jan Mlecka I was impacted by two basic factors: firstly by my three years of studies and internships in Lisbon – a metropolis on the shore of Atlantic ocean, which became written into Lisbon’s DNA, into its light, tempo, priorities, historz, courage, strength, eternity, simplicity, sailing boats and elegance. And secondly I was influenced by a workshop organized by AA of London in February 2011 in Dubrovnik with lectures of Vedran Mimica and John Palmesino about towns, growth, quality of town life, policies and by studies of Southern Croatian coast under leadership of Krunoslav Ivanišin, where a floating platform was proposed to simultaneously solve several problems of this region. The more I become involved with oceans, the more I am fascinated by shorelines. This rare, dangerous, fractal line is the theatre of the biggest changes and dramas, but it also presents the greatest possibilities. (This is why I call my work not Towns by Oceans but In Between The Oceans and The Earth). When I was mapping shorelines, I have come across several findings: 1. The principles of constructions on shorelines are similar all over the world. 2. There are similar evolutionary stages in usage of shoreline – it is both physical and functional stages. 3. In many cases the potential of ocean is impaired by human interventions. Taking into account these facts, I was searching for further evolutionary stages of shorelines. In Lisbon I visited Ocean Energy Systems where 30 young engineers work on im-provements of machines designed to extract energy from oceans. In order to be effi-cient, these machines have to have giant dimensions. Immediately after seeing a generator on the island of Pico, I realized that such machines should not be put behind fences, creating an obstacle on the rare shoreline in between the sea and the land, but that they must be adopted by architecture – so that we will be able to live with them in symbiosis on the shoreline.

Implementing a nonlinear gravity wave (GW) parameterization into a mechanistic middle and upper atmosphere model, which extends to the lower thermosphere (160 km), we study the response of the atmosphere in terms of the circulation patterns, temperature distribution, and migrating terdiurnal solar tide activity to the upward propagating smallscale internal GWs originating in the lower atmosphere. We perform three test simulations for the Northern Hemisphere winter conditions in order to assess the effects of variations in the initial GWspectrum on the climatology and tidal patterns of the mesosphere and lower thermosphere. We find that the overall strength of the source level momentum flux has a relatively small impact on the zonal mean climatology. The tails of the GW source level spectrum, however, are crucial for the lower thermosphere climatology. With respect to the terdiurnal tide, we find a strong dependence of tidal amplitude on the induced GW drag, generally being larger when GW drag is increased.

<p> Triassic sandstones form rapidly eroding cliffs around much of the Minas Basin, Nova Scotia. The sand eroded from these cliffs is one major source of the modern intertidal sands. Wave erosion of the cliffs locally produces a small sand beach at the high tide level. </p> <p> Eight samples were examined using the Scanning Electron Microscope: two from the Triassic sandstones, and six from the high-tide beach below the cliffs. All samples contained rounded, as well as subrounded and subangular, quartz grains in the 0.5 - 1.00 mm size fraction. As the samples originated in the cliffs, abrasion by strong tidal currents cannot account for the rounded grain shape. </p> <p> All grains studied had suffered some degree of diagenesis in the form of a precipitation coat. This was generally thicker on the rounded grains than on the more angular ones. The Triassic sandstone grains generally illustrated upturned plates, semiparallel steps, conchoidal breaks and a fine V-shaped pattern. The high beach grains illustrated upturned plates, V-shaped patterns, conchoidal breaks, greater rounding of featu res present and arc-shaped steps. Wehrfritz (1973) studied quartz grains from intertidal sand bars in the Minas Basin. He concluded that grains were considerably rounded by intertidal processes, and the frequency of V-shapes increased with grain roundness. </p> <p> Although some rounding of the beach sands was inherited, wave and tidal action aided in rounding the features further. The initial rounding of the sand grains within the sandstones may have occurred during periods in the Triassic when they were exposed to wind or reworked in the lakes. </p> / Thesis / Bachelor of Arts (BA)

Implementing a nonlinear gravity wave (GW) parameterization into a mechanistic middle and upper atmosphere model, which extends to the lower thermosphere (160 km), we study the response of the atmosphere in terms of the circulation patterns, temperature distribution, and migrating terdiurnal solar tide activity to the upward propagating small scale internal GWs originating in the lower atmosphere. We perform three test simulations for the Northern Hemisphere winter conditions in order to assess the effects of variations in the initial GW spectrum on the climatology and tidal patterns of the mesosphere and lower thermosphere. We find that the overall strength of the source level momentum flux has a relatively small impact on the zonal mean climatology. The tails of the GW source level spectrum, however, are crucial for the lower thermosphere climatology. With respect to the terdiurnal tide, we find a strong dependence of tidal amplitude on the induced GW drag, generally being larger when GW drag is increased.

No description available.

Alexandrium tamarense is a harmful algal species that can produce saxitoxins, a suite of powerful neurotoxins that bioaccumulate up the food chain and can have severe economic and health impacts. With harmful algal blooms increasing temporally and spatially, it is important for us to understand the relationship between harmful algal blooms and nutrients, particularly nitrogen from anthropogenic sources. To this end, the stable nitrogen isotopic composition (δ¹⁵N) of medium nitrate, algal cells and toxin in both nitrogen-replete and nitrogen-limited batch cultures of A. tamarense were measured in order to assess the potential for using the δ¹⁵N of the toxin as a tracer of the nitrogen source used for growth. A. tamarense cells grown under nitrate-replete conditions were depleted by 1.5‰ relative to the growth medium, and saxitoxin was depleted by 1.5‰ relative to the whole cells. Under nitrate-limiting conditions, the isotopic difference between cells and saxitoxin changed as nitrate in the growth medium was depleted, indicating uncoupling of toxin synthesis and cell growth rates under changing external nutrient conditions. Determination of the absolute magnitude of the isotopic differences between the medium nitrate and either the cells or the saxitoxin was confounded by 1) using two different nitrate sources – one nitrate source was used to grow the inoculum and a different nitrate source was used for the experimental medium - with different ‰ values and 2) the presence of an unidentified, isotopically-light, nitrogen blank in the low-nitrate medium samples. I conclude that STX nitrogen isotope values have the potential to be used as nitrogen source indicators. However, overall fractionation between whole cells and STX is unknown due to the uncoupling between cell growth and STX synthesis observed during my nitrogen-limited experiment. Based on previous research on cell growth and toxin production dynamics under different nutrient regimes, it is also reasonable to assume that the observed results here may differ if a different nitrogen source was utilized by the cells for STX production. Further research could include isotope analysis of cultures grown on different nitrogen sources, such as ammonium and urea; isotopic analysis of additional compounds, such as amino acids; or use of additional stable isotopes, such as C or O. / text

Ces travaux de thèse concernent la morpho-dynamique d'une plage de poche sableuse, située en environnement macrotidal. L'étude est menée sur la plage de Porsmilin, une plage de type intermédiaire avec une terrasse de basse mer. Cette étude s’appuie sur des observations in situ acquises lors de campagnes de mesures, organisées au cours de cette thèse. Le principal objectif est de caractériser le rôle de la pente, dans l'équilibre dynamique existant entre les processus hydrodynamiques et la morphologie de la plage. La dynamique des niveaux d’eau, de la propagation des ondes infragravitaires et de la turbulence sont examinés et mis en regard des variations morphologiques de la plage, en particulier de la pente locale de la plage. Les niveaux d’eau sont globalement sous-estimés par les formulations empiriques proposées dans la littérature. Des formules adaptées au site de Porsmilin sont présentées. L’impact de la brisure de pente observée le long du profil de plage sur la dynamique de la plage, est étudié. La variabilité de la position de la brisure de pente est impliquée dans les processus d’accommodation à court terme de la plage. Cela se traduit par un retrait vers le haut de plage de la brisure de pente, permettant une dissipation plus efficace de l’énergie incidente par la terrasse de basse mer. En revanche, ce retrait peut conduire, à une concentration d’énergie importante en haut de plage, lors de conditions particulièrement énergétiques, associées à un marnage important. La position de la brisure de pente pourrait être un bon indicateur de l'état de vulnérabilité de la plage face à des évènements énergétiques, ce qui constitue une information primordiale dans le contexte actuel d’érosion généralisée des littoraux sableux. / This PhD work is focused on the morphodynamic of a pocket beach, located in a macrotidal environment. The beach type is intermediate, with a low tide terrace. The study is based on in situ observations, collected during field campaigns organized during the PhD. The objective is to characterize the beach slope impact on hydrodynamics processes and beach morphology. The water levels dynamic, infragravity waves propagation and turbulence generation in the swash zone, are examined and linked to the beach slope variability.The empirical formulations proposed in the literature show large under-estimations of water levels in the site. Empirical formulations adapted to the beach are proposed.The characteristic break slope presents along the cross-shore profile of low tide terrace beaches is studied. The variability of the break slope location is relevant to explain the short term accommodation of the beach. Under incident wave energy, the location of the beach slope moves shoreward, allowing higher wave dissipation by the low tide terrace. Nevertheless, the reflective part is reduced, which leads to a vulnerable state of the upper beach under strong forcing associated with high tide. The location of the beach slope is found to be a good indicator of the beach vulnerability under a given wave forcing. It provides valuable information in the globalized beach erosion context.

Coral cover is in decline on a global scale, with increased mortality events being attributed to a number of global and regional stressors. While the impacts of global stressors (e.g. sea surface temperature rise, ocean acidification) are well documented, there is growing interest in identifying and understanding the impacts of regional stressors. The reason for this change in focus is that regional stressors can often work in combination, sometimes synergistically, with global stressors and that stressors on a regional scale tend to be more easily mitigated by management practices. One regional stressor that impacts a myriad of marine organisms in the southeastern United States is the annual red tide blooms produced by the dinoflagellate, Karenia brevis. Their impacts, along with the lipid soluble polyether neurotoxins they produce, termed brevetoxins, are well studied in economically important organisms, such as bivalves. However, little is known of their impacts on organisms that possess ecological importance, such as species of scleractinian coral. To address this gap in knowledge, a multifaceted study is discussed herein, which evaluated the effects of ecologically relevant concentrations of K. brevis and associated brevetoxins on different coral life history stages and coral species. The second chapter addresses the impacts of red tide on larval behavior, settlement and survival of the coral species Porites astreoides, as well as impacts of photochemical efficiency and oxidative stress within different coral species (P. astreoides larvae, P. astreoides adults, Acropora cervicornis, Cladocora arbuscula, and Phyllangia americana). The third chapter confers the use of broad-scale proteomic analysis to identify the cellular response of the non-model coral species, P. astreoides, following exposure to red tide. Coral larvae actively avoided both medium and high bloom conditions of K. brevis and brevetoxins, while percent larval settlement and survival were impacted following exposure to high bloom concentrations of K. brevis. Photochemical efficiency of in hospite Symbiodinium was reduced following exposure to both K. brevis and brevetoxin in P. astreoides larvae, as well as exposure to K. brevis in P. astreoides adults, while being unimpacted in A. cervicornis. Compared to controls, high bloom conditions resulted in an increase in biomarkers of lipid peroxidation in C. arbuscula. This was also seen in P. astreoides larvae at 24 hours; however, this difference was indistinguishable following 48 hours. Surprisingly, no other biomarker of oxidative stress analyzed were impacted. Broad-scale proteomic analysis of P. astreoides following exposure to red tide conditions revealed variable changes in proteome expression depending on if the corals were exposed to K. brevis or brevetoxins. Exposure to brevetoxins resulted in differential expression of proteins related to DNA organization, chromatin formation and transcription expression; while exposure to K. brevis resulted in differential expression of proteins related to redox homeostasis, protein folding, energy metabolism, and production of reactive oxygen species. The results of this study demonstrate the potential for annual red tide blooms to act as a regional stressor on coral species. They highlight the ability of red tide conditions to negatively impact coral at multiple life history stages and that the extent of these effects may be species specific. They also provide further incite of coral’s response to red tide exposure at the cellular level.

The objective of this dissertation is to gain a better understanding of the environmental and climatic effects on the temporal and spatial variability of phytoplankton biomass along the West Florida Shelf. Chapter 1 examines temporal and spatial patterns in chlorophyll concentrations using satellite data collected between 1997 and 2003. Chlorophyll data derived from the SeaWiFS sensor are validated with in-situ data and analyzed. Wind, current, sea surface temperature, river, and rain data are used to better understand the factors responsible for the patterns observed in the satellite data. My question is whether the standard OC4 algorithm is adequate for studying short-term variability of chlorophyll concentrations along the WFS. I will examine temporal and spatial trends using the OC4 and compare them to the Carder semianalytical algorithm which uses remote sensing reflectances at 412nm, 443nm, 490nm,and 555nm to estimate chlorophyll concentrations separately from CDOM estimates. In Chapters 2 and 3 the potential problems due to CDOM and bottom reflectance are examined. In Chapter 2 I analyze the influence of riverine induced CDOM. Water leaving radiances are analyzed in an effort to discriminate true chlorophyll patterns from CDOM contaminated signals. Chapter 3 examines the impact of bottom reflectance on the satellite signal by using the percentage of remote sensing reflectance at a wavelength of 555 to differentiate between optically shallow waters and optically deep waters. Optically shallow waters are defined as those with the percentage of Rrs at 555 due to bottom reflectance greater than or equal to 25 percent, while optically deep waters have percent bottom reflectance less than or equal to 25 percent. These analyses will help assess the validity of the temporal and spatial patterns ofchlorophyll concentration observed with the SeaWiFS data described in Chapter 1.

Μελετάται αριθμητικά η υδροδυναμική κυκλοφορία του Πατραϊκού κόλπου. Σκοπό αποτελεί η κατανόηση της τρισδιάστατης δομής της ροής που προκαλείται υπό διάφορες φυσικές φορτίσεις, δηλαδή τον άνεμο, την παλίρροια και τη στρωμάτωση. Η αριθμητική προσομοίωση γίνεται με τον τρισδιάστατο αριθμητικό κώδικας πεπερασμένων όγκων MIKE 3 FM (HD,TR). Η ανεμογενής κυκλοφορία, κατά τους χειμερινούς μήνες οπότε ο κόλπος σύμφωνα με μετρήσεις είναι ομογενής, παρουσιάζει στοιχεία ροής μεγάλης κλίμακας, με επιρροή από τη δύναμη Coriolis, ανάπτυξη στρώματος Ekman και ισχυρά ρεύματα επιστροφής, λίγα μέτρα κάτω από την ελεύθερη επιφάνεια. Ταυτόχρονα, σε περιοχές όπως η θέση του στενού Ρίου-Αντιρρίου η ροή συμπεριφέρεται περισσότερο ως υδραυλική ροή με ταπείνωση της ελεύθερης επιφάνειας και κατακόρυφο προφίλ ταχύτητας, όμοιο με της τυρβώδους ροής Couette. Στην οριζόντια διεύθυνση, η ροή παρουσιάζει έντονα παράκτια ρεύματα και κλίση της ελεύθερης επιφάνειας. Εκτιμάται ότι ο χρόνος ανανέωσης των υδάτων για τον κόλπο θα κυμαίνεται από ένα μήνα έως μία εβδομάδα, ανάλογα με την ένταση του ανέμου. Φαίνεται ότι στα βαθύτερα στρώματα του Πατραϊκού η ανεμογενής ροή δεν επιδρά σημαντικά στην ανανέωση των υδάτων, τα οποία παραμένουν εγκλωβισμένα και επανακυκλοφορούν μεταξύ των δύο εγκάρσιων ραχών που οριοθετούν την λεκάνη του. Τα παλιρροϊκά ρεύματα, τα οποία είναι σημαντικά στον Πατραϊκό, καθορίζουν την κυκλοφορία των υδάτων στο κύριο σώμα του κόλπου και στο στενό Ρίου-Αντιρρίου, ενώ η ανεμογενής ροή είναι καθοριστική κοντά στις ακτές. Η συνδυασμένη δράση ανέμου και παλίρροιας προκαλεί κυκλωνικούς και αντικυκλωνικούς στροβίλους, πλησίον των βορείων και νοτίων ακτών του Πατραϊκού, η φορά των οποίων υπαγορεύεται αποκλειστικά από τα ισχυρά ανεμογενή παράκτια ρεύματα. Η μελέτη της καλοκαιρινής κυκλοφορίας αναδεικνύει σημαντικές διαφορές, σε σύγκριση με την χειμερινή κυκλοφορία των υδάτων στον Πατραϊκό κόλπο. Τα ανεμογενή ρεύματα είναι αμελητέα από τη ζώνη του θερμοκλινούς και κάτω, για τη μέση ένταση ανέμου, ενώ η ένταση της τύρβης περιορίζεται στο επιλίμνιο. Την καλοκαιρινή περίοδο η δράση νοτιοδυτικού ανέμου συνδέεται με την παρουσία αναβλύσεων στις βορειοδυτικές ακτές του όρμου της Ναυπάκτου και στο μέτωπο της λιμνοθάλασσας του Μεσολογγίου. Αναβλύσεις εντοπίζονται και νοτιοδυτικά του Ρίου, μπροστά από την πόλη των Πατρών, για βορειοανατολικούς ανέμους. Στο στενό Ρίου-Αντιρρίου η δράση του ανέμου, αλλά και η παλίρροια οδηγούν στη γένεση εσωτερικών κυμάτων τα οποία προκαλούν κατακόρυφη κυκλοφορία. Κύριο χαρακτηριστικό της κυκλοφορίας των υδάτων στον Πατραϊκό, την καλοκαιρινή περίοδο, είναι ο ισχυρός κυκλωνικός στρόβιλος που παρατηρείται στο κέντρο του κόλπου αναγκάζοντας τα ύδατα σε περιστροφική κίνηση. Με βάση τις αριθμητικές προσομοιώσεις η ύπαρξη ισχυρού κυκλωνικού στροβίλου συνδέεται αποκλειστικά με την παρουσία βορειοανατολικού ανέμου και συγκεκριμένα στη φάση της πλημμυρίδας. Τέλος, με βάση τις αριθμητικές προσομοιώσεις υπολογίζεται το τρισδιάστατο πεδίο ρευμάτων στην ευρύτερη περιοχή του παλαιού και νέου λιμένα Πατρών, καθώς και η διάχυση και μεταφορά των επεξεργασμένων λυμάτων από τον αγωγό της ΔΕΥΑΠ. / The hydrodynamic circulation in the Gulf of Patras, in Western Greece, is studied using three-dimensional numerical simulations. The simulations are performed using the three-dimensional modeling system MIKE 3 FM (HD/TR). The wind-induced circulation is examined in the natural basin of the Gulf of Patras, in which batotropic flow develops, according to field measurements, during the winter months. The simulations show that the wind-induced flow creates strong currents near the coasts, which determine the sense of rotation of the gyres that develop in the Gulf. Strong currents are also created at the Rio-Antirio straits. The wind-induced, barotropic currents do not seem to contribute to the renewal of bottom waters, which recirculate between the two sills. Depending on the speed of the wind forcing the flow, the residence time of the waters in the Gulf of Patras is estimated to range from one month to one week. The tide-induced circulation is important in the Gulf of Patras. Strong, tidal currents have been simulated to develop at the straits of Rio-Antirrio and in the main body of the Gulf, with cyclonic and anticyclonic eddies developing at the northern and southern coasts, respectively. When there is also wind blowing, nearshore gyres develop, the sense of rotation of which is by the wind direction, while in the central part of the Gulf the flow pattern is dictated by the tidal action. Further, the baroclinic wind and tide-induced circulation are studied to investigate the effect of stratification on the structure of the flow. During the summer period the wind-induced flow and the wind generated turbulence driven by winds of medium strength are restricted to the upper layer of the epilimnion, while the strong winds cause tilt and erosion of the thermocline in the central part of the Gulf and generation of internal waves at the straits of Rio-Antirio. Salient features of the summer circulation are the strong upwellings and the central cyclonic gyre which are predicted using numerical simulations. Upwellings occur along the northwesterly portion of the Nafpaktos bay coasts at the westerly part of the Gulf of Corinth, under southwesterly wind, and to the south of Rio cape at the front of the city of Patras, under northeasterly wind. Concerning with the central cyclonic eddy, according to numerical simulations it develops exclusively during the flood tide under the simultaneous action of northeasterly winds. The numerical predictions were validated against satellite images of the surface temperature field determined by NOAA-6 and NOAA-7 which closely confirm the simulation results. Finally, the simulated barotropic and baroclinic flow fields are applied to the calculation of the currents near the port of Patras and to the advection and diffusion of the treated sewage effluents disposed of near the southeasterly coast of the Gulf, near the city of Patras.