Browsing by Subject "Internal waves"
Now showing items 1-13 of 13
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A wave-theoretic method for estimating the effects of internal tides on acoustic wave transmission
(NATO. SACLANTCEN, 1975/10)The effect of the first mode semidiurnal internal tide on a ducttype sound speed profile was approximated by varying the minimum velocity of the parabolic profile in a sinusoidal fashion with a period of 12.42 hours. The ... -
Influence of internal waves on sound propagation in the SOFAR channel
(NATO. SACLANTCEN, 1975/10)In this paper theoretical investigations due to the influence of internal waves to sound propagation in the SOFAR-channel are presented. The undisturbed acoustic field is described by a normal-mode model. The disturbance ... -
Mixed layer deepening and variability in the upperlayers if the central western Mediterranean, MILEX-82: final report
(NATO. SACLANTCEN, 1988/10)The 1982 Mixed-Layer Experiment (MILEX-82) is described in detail and the data are presented in ways designed to illustrate the spatial and temporal variability of the surface and deeper layers of the central western ... -
Model statistics of inertial shear from multi- year simulations at weathership 'Mike': currents, atmospheric forcing, internal waves, mixed layer, Norwegian Sea)
(NATO. SACLANTCEN, 1990/12)In this memorandum we focus on one of the most important environmental -
Observed sound velocity and temperature profiles in the Strait of Gibraltar during the passage of an internal wave
(NATO. SACLANTCEN, 1966/10)Sound velocity and temperature measurements taken from the sea-surface to 350 m depth, close to one spot over a 24-hour period revealed the passage of an internal wave of approximately 60 m amplitude. The effect of this ... -
Obtaining the ocean index of refraction spectrum from the acoustic amplitude fluctuations
(NATO. SACLANTCEN, 1997)The feasibility of using acoustic measurements to determine the properties of a shallow water internal wave field is investigated through numerical simulations. The random intemal wave field is modeled by a generalized ... -
Oceanographic analysis of NAPOLI'85, an experiment in the Tyrrhenian Sea
(NATO. SACLANTCEN, 1990/03)In 1985, an acoustic/oceanographic experiment (NAPOLI '85) was carried out in the Tyrrhenian Sea to investigate acoustic propagation -
Short-period vertical displacements of the upper layers in the Strait of Gibraltar: part 1 - text: part 2 - diagrams
(NATO. SACLANTCEN, 1964/11)The report is principally based on observations of short-term displacements made by the author in the summers of 1958, 1959, and 1961, using a thermistor chain. Pilot tubes installed on the thermistor chain made simultaneous ... -
Some acoustic effects of internal macrostructure
(NATO. SACLANTCEN, 1975/10)Some recent experimental developments relating to internal oceanographic- acoustic interactions are reviewed. Besides amplitude and phase fluctuations, a major concern is scattering into shadow regions. Associated oceanographic ... -
Time series variability in fluctuating ocean waveguides
(NATO. SACLANTCEN, 1999/07)The variability of signals propagating through an uncertain sound speed structure is addressed. Signals are assumed to travel in a narrow band adiabatically in modes and to experience fluctuations in sound speed which are ... -
Transmission-time variability, vertical spatial and temporal analysis of NAPOLI'85, an experiment in the Tyrrhenian Sea
(NATO. SACLANTCEN, 1989/09)An acoustic propagation experiment (NAPOLI '85) was carried out in the Tyrrhenian Sea in October 1985 in which signals from a broadband source were recorded at a range of 5 km with a vertical 62-m hydrophone array over a ... -
Two dimensional internal-wave spectra
(NATO. SACLANTCEN, 1975/10)Although spatial fluctuations of the sound speed in the ocean have a variety of causes, internal waves are thought to produce most of the fluctuations over horizontal scales ranging from several tens of metres to several ... -
Variability in the Gulf of Cadiz: internal waves and globs
(NATO. SACLANTCEN, 1980/08)An experiment was performed in the Gulf of Cadiz during June 1977, with the objective of separating oceanic variability due to internal waves from that due to inhomogeneities of the water. A CTD which oscillates in depth ...