Download or read book Wave Propagation in the Central Equatorial Pacific Ocean written by Kathleen A. Donohue and published by . This book was released on 1995 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Equatorial Pacific Ocean Climate Studies EPOCS written by and published by . This book was released on 1985 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Introduction to the Dynamics of El Nino and the Southern Oscillation written by Allan J. Clarke and published by Elsevier. This book was released on 2008-01-28 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many scientists either working on the El Niño/Southern Oscillation (ENSO) problem or its many applications have not been trained in both the equatorial ocean and atmospheric dynamics necessary to understand it. This book seeks to overcome this difficulty by providing a step by step introduction to ENSO, helping the upper level graduate student or research scientist to learn quickly the ENSO basics and be up to date with the latest ENSO research. The text assumes that the reader has a knowledge of the equations of fluid mechanics on a rotating earth and emphasizes the observations and simple physical explanations of them. Following a history of ENSO and a discussion of ENSO observations in Chapters 1 and 2, Chapters 3-5 consider relevant equatorial ocean dynamics, Chapters 6 and 9 relevant atmospheric dynamics, and Chapters 7 and 8 the main paradigms for how the Pacific Ocean and atmosphere couple together to produce ENSO. Chapter 8 also discusses the old mystery of why ENSO tends to be locked in phase with the seasonal cycle. Successful dynamical and statistical approaches to ENSO prediction are discussed in Chapters 10 and 11 while Chapter 12 concludes the book with examples of how ENSO influences marine and bird life. Quick reference guide and step by step introduction to El Niño/Southern Oscillation dynamics Keep informed and up to date on El Niño/Southern Oscillation research and how El Niño and the Southern Oscillation can be predicted Understand how El Niño can affect marine and bird life

Download or read book Upper Ocean Internal Waves in the Central Equatorial Pacific written by Timothy John Boyd and published by . This book was released on 1989 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tropical Instability Waves and Mixing in the Equatorial Pacific Ocean written by Ryan Mahony Holmes and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The unique dynamics of the equatorial oceans play an important role in the El Nino - Southern Oscillation (ENSO) and the ocean's meridional overturning circulation (MOC), both of which are critical processes that drive global climate variability on a range of time-scales. This dissertation makes a number of contributions to our understanding of equatorial ocean dynamics, lateral and vertical mixing at the equator, the behavior of equatorial waves and deep equatorial mixing, with implications for both ENSO and the MOC. The main contributions are: 1) Tropical instability waves (TIWs), the main drivers of lateral eddy mixing in the eastern equatorial Pacific, share a number of dynamical features with submesoscale flows in the mid-latitudes. In particular, their formation depends on the detailed frontal dynamics and sharp vertical gradients around their fringes, with implications for TIW energetics and the accurate representation of TIWs in low-resolution ocean models. 2) TIWs drive modulations in vertical mixing by altering the vertical shear of the Equatorial Undercurrent (EUC) through horizontal vortex stretching. This modulation can drive net sea surface cooling over the eastern Pacific cold tongue that may partially offset the warming driven by TIW lateral mixing. The magnitude of the net cooling depends on the mixing scheme used to parameterize vertical mixing, with implications for the role of TIWs in the mixed-layer heat budget in different ocean models. 3) Downwelling (upwelling) equatorial Kelvin waves can drive large decreases (increases) in the amplitude of the TIW field in the eastern equatorial Pacific and thus TIW-driven lateral and vertical mixing. The Kelvin waves alter the strength and structure of the background flow from which the TIWs gain energy, resulting in complex changes to the TIW energy budget. One major sink of TIW energy, the downward radiation of waves, is strongly altered with implications for deep and abyssal equatorial ocean circulation. 4) Mixing in the abyssal equatorial Pacific can exhibit a seafloor-intensified vertical structure even over smooth topography. The generation and breaking of lee waves over smooth topography at low latitudes is one possible mechanism that could contribute to this mixing. However, downward-propagating equatorial waves generated at the surface by TIWs or wind events could also supply energy for seafloor-intensified mixing through two possible mechanisms, wave trapping due to the horizontal component of Earth's rotation and inertial instability initiated by wave-driven displacement of fluid away from the equator. These results suggest that more attention should be devoted to measuring and understanding mixing over smooth topography in the abyssal equatorial oceans because of its potential role in the global overturning circulation.

Download or read book High Resolution Numerical Modelling of the Atmosphere and Ocean written by Kevin Hamilton and published by Springer Science & Business Media. This book was released on 2007-12-25 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: This highly relevant text documents the first international meeting focused specifically on high-resolution atmospheric and oceanic modeling. It was held recently at the Earth Simulator Center in Yokohama, Japan. Rather than producing a standard conference proceedings volume, the editors have decided to compose this volume entirely of papers written by invited speakers at the meeting, who report on their most exciting recent results involving high resolution modeling.

Download or read book Near annual SST Variability in the Equatorial Pacific in a Coupled General Circulation Model written by Renguang Wu and published by . This book was released on 2004 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Equatorial Pacific Ocean Climate Studies EPOCS written by and published by . This book was released on 1985 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dynamics of Seasonal and Interannual Variability in the Equatorial Pacific written by Xuri Yu and published by . This book was released on 1998 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tropical Instability Waves in the Pacific Ocean written by Simona Masina and published by . This book was released on 1996 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book EPOCS Equatorial Pacific Ocean Climate Studies written by and published by . This book was released on 1982 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Observations and Modelling of Deep Equatorial Currents in the Central Pacific written by Rui Vasques de Melo Ponte and published by . This book was released on 1988 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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. Time-lagged coherence calculations revealed evidence for vertical shifting of the jets on interannual time scales. Interpretation of results in terms of single frequency linear wave processes led to inconsistencies, but finite bandwidth (in frequency and wavenumber) Kelvin wave processes of periods on the order of three to five years could account for the observations. Thus, the records do not preclude equatorial waves as a reasonable kinematic description of the jets. At all wavenumber bands in general, power levels decayed away from the equator over scales broader than the Kelvin wave scale, suggesting the presence of Rossby wave energy. Cross-spectral analysis showed Rossby and Kelvin wave motions to be dominant at the equator over the 933 sm and the 140-400 sm vertical wavelength bands, respectively. The latter agrees with the findings of Eriksen (1981) in the western Pacific, and thus seems to be a climatological feature of the deep equatorial Pacific fields. In an attempt to model the observed zonal velocity signals, alternative forcing mechanisms for the deep ocean (other than direct surface winds) were tried. The probable presence of deep energy sources at the ocean side walls (e.g., Kawase, 1987) was explored by considering the linear response of an equatorial ocean to a time varying zonal jet placed at the lateral boundaries. In another simple model, we examined the character of stationary Kelvin wave solutions obtained in the presence of vertically sheared mean westward flows. In this case, the waves are forced below the thermocline by a vertical velocity representing large scale convergence or divergence patterns associated with the upper ocean circulation. Results suggest that both ideas remain potentially important to the existence of deep baroclinic currents in the equatorial ocean.

Download or read book Tropical Ocean atmosphere Newsletter written by and published by . This book was released on 1983 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Observation of High Frequency Internal Waves in the Pacific Ocean written by Robert Libman Zalkan and published by . This book was released on 1968 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations of high frequency internal waves were made from 1 to 14 December 1966, in the deep sea off Baja, California. The fluctuations of the depth of an isotherm were measured with a three-element horizontal array attached to a stable platform. The waves are characterized as a broad band phenomenon with a continuous distribution in frequency. For short intervals of time, a narrow frequency band within the continuum is adequately described as a horizontally plane wave of a single vertical mode. Furthermore, this simplified structure is stationary over time spans of several days. High modes are present in the low frequency waves. Above 4 cycles per hour, however, the first mode predominates. The spectral shape is consistent with the shear limited equilibrium spectrum proposed by Phillips (1966). In addition, the predominance of the first mode at high frequencies further emphasizes the importance of shear instability in internal wave propagation. The horizontal properties of the wave field indicate well-defined directions of narrow-band propagation. These directions and the dispersive properties of the propagation have led to the identification of local topographic features in generating areas of internal waves. (Author).

Download or read book Pacific Marine Environmental Laboratory Summary Report Fiscal Year written by Pacific Marine Environmental Laboratory (U.S.) and published by . This book was released on 1984 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Observational Study of Long Waves in the Equatorial Pacific Ocean During the 1991 1993 El Ni o written by Todd William Sitler and published by . This book was released on 1994 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Long waves in the equatorial Pacific Ocean during the 1991-1993 El Nino event were examined using temperature, current, and wind time series from the Tropical Oceans-Global Atmosphere Tropical Atmosphere-Ocean (TOGA-TAO) moored buoy array. Numerous episodes of long wave activity were detected. The most prominent episodes were associated with eastward propagating equatorial Kelvin waves and with westward propagating tropical instability waves and mixed Rossby-gravity waves. Equatorial Kelvin waves, which were generated by westerly wind events in the western and central Pacific, were evident in the data between 2 deg N to 5 deg S and from 170 deg W to 110 deg W. These Kelvin waves, which were most pronounced from 75 to 300 m, had periods of 40 to 70 days, eastward phase speeds of 1.9 to 6.5 m/s, and zonal wavelengths on the order of 10,000 km. These waves were most evident in the northern hemisphere fall and winter. The period of greatest Kelvin wave activity was August 1991 -May 1992, during the peak phase of the 1991-1993 El Nino event.

Download or read book Propagation and Forcing of High Frequency Sea Level Variability in the Eastern Equatorial Pacific written by M. Pilar Cornejo-Rodriguez and published by . This book was released on 1987 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sea level and wind data from coastal and island stations from Buenaventura, Colombia (4°N) to Callao, Peru (12°S) have been analyzed for the 1979-1984 time period, to describe the seasonal and interannual variations in the characteristics of short time scale variability (1-2 weeks). Auto- and cross spectral analyses are used to make comparisons between Austral summers and winters as well as interannual comparisons between the 1982-1983 El Nino/Southern Oscillation (ENSO) period and non-ENSO years. The principal results show weak evidence of local forcing of the sea level by the alongshore wind during the whole year without significant differences between summer and winter seasons. The alongshore coherence and phase spectra between the sea level series show evidence of poleward propagating fluctuations at speeds of 2.6-3.0 ms^-1 during winter, but no propagation is evident during summer. There is also a large energy increase in coastal sea level, especially in the 8-11 day band, during the 1982-1983 ENSO episode. This increase is associated with a non-dispersive, poleward propagation of events at speeds of 3.11-3.6 ms^-1. The propagating fluctuations are superimposed on a weak, locally forced variability. The only plausible source for the observed coastal fluctuations appears to be trapped waves in the equatorial waveguide. Additional equatorial data from subsurface pressure gauges in the Galapagos Islands and inverted echo sounders at 3°N,95°W, 3°N,85°W and 2°S,85°W are used to explore the possibility that the coastal signal during the 1982-1983 ENSO episode is connected to the arrival of energy in the form of equatorially trapped Rossby-gravity (Yanai) and Kelvin waves, and to determine the respective contributions of the two wave types. Cross spectral analyses, frequency domain EOF analysis and the characteristics of equatorial waves demonstrate that equatorially trapped Yanai waves are the principal source of the propagating signals in the coastal sea levels during the 1982-1983 ENSO. During the 1982-1983 ENSO, between 64% and 91% of the coastal SLH variability in the 8-11 day period band is associated with antisymmetric variability across the equator. Phase in this band is zonally invariant along the equator but is poleward propagating along the coast, consistent with the conversion of stationary, equatorial lanai waves into coastal trapped waves.