1,210 research outputs found
Inertial oscillations in the Mediterranean
Submitted in partial fulfillment of the requirements of the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June, 1970Measurements of ocean currents were made by the
author in the Western Mediterranean Sea at five depths
for two months during early 1969. In terms of the dominant
and persistent presence of inertial oscillations,
circularly polarized currents having periods of a half
pendulum day, the data are among the most striking
ever collected.
Two contemporary theories have been adapted for
interpretation of this data. On the basis of a ray or
short-wave-length theory, energy arriving at the observing
site is found to fall into two categories, that
making direct arrival from the, surface where it is assumed
to have been generated, and that which undergoes
one or more reflections. To the extent that the
former dominates, it is found that the Algerian Coast
about 130 km. to the south would cast a shadow to the
north, the precise shape of which would be highly
dependent on small variations in frequency. The nature
of this frequency dependence implies a gradual increase
in frequency with depth at the observing latitude.
Although the data show a measurable shift (about 3%)
towards higher frequencies, which is roughly the
required amount, the lack of progressive frequency
change with depth does not support the shadow
hypothesis.
In addition, the data is interpreted in terms of
normal mode theory, where the nearby coast is seen to
force a discrete modal structure to the solutions.
The observed variation of current phase with depth
indicates that a single internal mode dominates over
a large portion of the data, while variations of both
current amplitude and phase with depth are consistent
this being the third internal vertical mode. Existence
of a normal mode is also consistent with the long time,
on the order of three weeks, for which the oscillations
were observed to persist and with the dimensions of
the Mediterranean Basin.This work was supported by the National Science Foundation
under contract GA10208 and by the Office of Naval
Research under
contract NONR 241-11
Stand Up And Sing For Your Father An Old Time Tune : Novelty Waltz Song
https://digitalcommons.library.umaine.edu/mmb-vp/5485/thumbnail.jp
Plimne oscilacije u sjevernom Jadranu: opažanja, modeliranje varijacijskom asimilacijom podataka i linearna plimna dinamika
Fifteen open-sea time-series observations of tidal velocities and tidal bottom pressures for more than six months duration provide a new database for North Adriatic tides. The observations show nearly reversing tidal currents at most locations and increasing tidal-current strength near Istria. Tidal elevation amplitudes and phases respectively increase northwestward and counterclockwise, strongly for semidiurnal tides and weakly for diurnal tides. The data are used for optimal determination of boundary conditions for a linear strong-constraint variational data assimilation model and the resulting average rms difference errors for tidal elevations and currents are below 1 cm and 0.5 cm/s, respectively. The Q factors from the model are 14.0 for M2 and 22.4 for K1, but comparisons between frictional dissipation estimated from the model and from the data suggest that model dissipation values could be too high by a factor of two and Q factors too small. Model potential energy is 1.5 times kinetic energy for M2 and 6.1 times kinetic energy for K1. Observational and modeling results suggest that energy fluxes from Kvarner Bay are significant in the North Adriatic tidal energy balance. M2 energy fluxes support the concept of an incident and reflected Kelvin wave in the North Adriatic with some modification. K1 energy fluxes show a northeastward cross-basin flux near the 50 m isobath where the bathymetric slope is particularly steep, with Kelvin-wave-like structures north of the ridge and departures from Kelvin--wave structure south of the ridge.Petnaest vremenskih nizova mjerenja plimnih struja i pridnenih tlakova na otvorenom moru, u razdoblju duljem od Å”est mjeseci, predstavlja novu bazu podataka za plimne oscilacije sjevernog Jadrana. Opažanja pokazuju gotovo obrat plimnih struja na veÄini lokacija i poveÄanje njihove snage u blizini Istre. Amplitude plimnih denivelacija poveÄavaju se prema sjeverozapadu, a faze rastu u smjeru suprotno od kazaljke na satu, jako za poludnevnu komponentu, slabo za dnevnu. Podaci su upotrijebljeni za optimalno odreÄivanje rubnih uvjeta u linearnom modelu koji je koriÅ”ten kao strogi uvjet u varijacijskoj asimilaciji. Dobiveno srednje kvadratno odstupanje za plimne denivelacije je manje od 1 cm, a za plimne struje manje je od 0.5 cm/s. IzraÄunati Q-faktori za model su 14.0 za M2 komponentu i 22.4 za K1 komponentu, ali usporedbe izmeÄu disipacije trenjem procijenjene iz modela i iz mjerenja sugerira da su vrijednosti disipacije u modelu prevelike za faktor 2, te da su vrijednosti Q faktora premale. Modelirana potencijalna energija je 1.5 puta veÄa od kinetiÄke energije za M2 komponentu i 6.1 puta veÄa od kinetiÄke energije za K1 komponentu. Rezultati mjerenja i modela sugeriraju da protoci energije iz Kvarnerskog zaljeva daju znaÄajan doprinos ravnoteži plimne energije u sjevernom Jadranu. Protoci energije M2 komponente podržavaju koncept upadnog i reflektiranog Kelvinovog vala u sjevernom Jadranu uz neke modifikacije.
Protoci energije K1 komponente pokazuju popreÄni tok u smjeru sjeveroistoka u blizini 50 m izobate gdje je nagib dna osobito strm, sa strukturama sliÄnima Kelvinovom valu sjeverno od grebena i odstupanja od Kelvinovog vala južno od grebena
Ispravak u radu: āPlimne oscilacije u sjevernom Jadranu: opažanja, modeliranje varijacijskom asimilacijom podataka i linearna plimna dinamikaā
A precision/round-off error has been discovered in the tidal analysis routines used in the paper āNorth Adriatic tides: observations, variational data assimilation modeling, and linear tide dynamicsā by J. W. Book, H. Perkins, and M. Wimbush (2009, Geofizika, 26, 115ā143). Tidal elevation phases for 12 of the 15 stations are, on average, too low by 3.9Ā° for the diurnal constituents and 7.9Ā° for the semidiurnal constituents in Tabs. 4 and 5. These tables have been corrected and are republished here.
The error also had an effect on the input data used for the linear variational data assimilation model, and combined with a nearest neighbor interpolation scheme produced an approximate 15 minute forward shift in time for 6 of the 43 synthesized tidal records. The error produced final model solutions that had tidal elevation phases 3.5Ā° too high for M2, 1.6Ā° too high for K1, and similar matching phase shifts for other semidiurnal and diurnal constituents.
The errors in the input data have been corrected, the interpolation scheme has been changed to a piecewise cubic spline method, and the model runs have all been redone. The new model results suggest a minor change in optimal friction parameter, which in turn alters model Q factors and dissipation. However, the original finding that these values are not well determined by this methodology remains true. Model and observational results originally shown in Figs. 5ā7 and Figs. 13ā14 have slightly changed and are republished here. The main conclusions from the original work regarding Kelvin waves and TRW dynamics for the North Adriatic basin remain unaltered by these corrections.Otkrivena je pogreÅ”ka zaokruživanja u rutinama za plimnu analizu u radu J. W. Book, H. Perkins i M. Wimbush: āPlimne oscilacije u sjevernom Jadranu: opažanja, modeliranje varijacijskom asimilacijom podataka i linearna plimna dinamikaā (Geofizika, 26, 2009, 115ā143). Faze plimnih denivelacija, dane u tablicama 4. i 5., za 12 od 15 postaja podcijenjene su u prosjeku 3,9Ā° za dnevne komponente te 7,9Ā° za poludnevne komponente. Ovdje dajemo tablice s ispravljenim vrijednostima. GreÅ”ka je utjecala na ulazne podatke koji su koriÅ”teni u linearnom modelu za varijacijsku asimilaciju podataka te je, u kombinaciji s interpolacijskom shemom najbližeg susjeda, uzrokovala vremenski pomak unaprijed od približno 15 minuta za 6 od ukupno 43 sintetizirana plimna zapisa. GreÅ”ka je proizvela konaÄna modelska rjeÅ”enja koja su precijenila faze plimnih denivelacija za 3,5Ā° za M2 komponentu, 1,6Ā° za K1 komponentu, te fazne pomake sliÄnih iznosa kod drugih poludnevnih i dnevnih komponenti. GreÅ”ke u ulaznim podacima su ispravljene, interpolacijska shema je promijenjena tako da koristi po dijelovima kubne spline-ove te su ponovno provedeni modelski raÄuni. Novi rezultati modela sugeriraju malu promjenu u optimalnom parametru trenja, koji dalje mijenja Q faktore modela i disipaciju. MeÄutim izvorni nalaz, da te vrijednosti nisu dobro odreÄene ovom metodologijom, ostaje nepromijenjen. Rezultati modela i opažanja, izvorno prikazani na slikama 5.ā7. i 13.ā14., malo su se promijenili i ovdje su nanovo prikazani. Glavni zakljuÄci iz izvornoga rada u vezi s Kelvinovim valovima i TRW dinamikom u sjevernom Jadranu nakon ovih ispravki ostaju isti
N. E. A. 1903
Envelope labelled N. E. A. 1903, containing cards and a second envelope relating to the National Educational Association
Stand Up and Sing for Your Father
A list of song titles.https://scholarsjunction.msstate.edu/cht-sheet-music/1592/thumbnail.jp
āBloodwoodā and āLiminal Spaces, Timeless Places: Abjection, Liminality and Landscape in Australian Gothic Fictionā
This creative honours project comprises a work of fiction titled āBloodwoodā and an accompanying exegetical essay, exploring the concept of liminal space within the Australian landscape. It investigates the anxieties and consequences of past trauma that linger within the landscape of modern Australia, exploring themes such as time, connection to nature, trauma and grief. Using Julia Kristevaās abjection theory, particularly her ideas on liminal space, this work addresses the contentious issue of postcolonial theory within the field of literary studies, as well as the concept of grief as a liminal process. These ideas are explored through the storylines of three interwoven protagonists, as they each navigate their own altered realities following personal trauma or loss, within a shared physical landscape. Abjection, as well as other elements of the Australian Gothic literary genre, is used to convey discomfort and unease within the landscape, linking the three separate protagonists to an established site of trauma. The project also delves into ecocriticism to address ways in which the Australian landscape is viewed and represented within Australian gothic literature.
This thesis was conducted using a practice-led research, research-led practice methodology combined with textual analysis of several key works within the genre of the Australian Gothic, analysed using the framework of Kristevaās abjection theory, which in-turn influenced the writing of the creative piece āBloodwoodā
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