Low‐frequency, direct‐path acoustic reverberation near the Mid‐Atlantic Ridge

1995 ◽  
Vol 98 (5) ◽  
pp. 2987-2987
Author(s):  
Jerald W. Caruthers ◽  
Jorge C. Novarini
Keyword(s):  
Low Frequency ◽  
Direct Path ◽  
Mid Atlantic Ridge ◽  
Acoustic Reverberation

Acoustic Reverberation at Selected Sites in the Mid-Atlantic Ridge Region,

1993 ◽  
Author(s):  
Jerald W. Caruthers ◽  
J. R. Fricke ◽  
Ralph A. Stephen
Keyword(s):  
Mid Atlantic Ridge ◽  
Acoustic Reverberation

Energy Transmission by Barotropic Rossby Waves Revisited

2005 ◽  
Vol 35 (11) ◽  
pp. 2228-2236 ◽  
Author(s):  
R. P. Matano ◽  
E. D. Palma
Keyword(s):  
Cross Section ◽  
Rossby Waves ◽  
Bottom Topography ◽  
Low Frequency ◽  
Energy Transmission ◽  
Low Pass ◽  
Mid Atlantic Ridge ◽  
High Frequency Waves ◽  
The Individual ◽  
Matching Techniques

Abstract This article presents a semianalytic method to investigate the properties of energy transmission across bottom topography by barotropic Rossby waves. The method is first used to revisit the analytical estimates derived from wave-matching techniques and Wentzel–Kramers–Brillouin (WKB) approximations. The comparison between the semianalytic method and WKB indicates that the results of the latter are valid for waves with periods longer than a month and ridges taller than ∼1000 m and wider than ∼500 km. For these parameter values both methods predict the passage of low-frequency waves and the reflection of high-frequency waves. The semianalytic method is then used to discuss the energy transmission properties of a cross section of the Mid-Atlantic Ridge. It is shown that the filtering characteristics of realistic bottom topographies depend not only on the spatial scale set by the cross-section envelope, but also on the scales of the individual peaks. This dependence is related to the fact that topographies narrower than ∼400 km (e.g., peaks) are high-pass filters of incoming waves, while topographies wider than that (e.g., cross-section envelopes) are low-pass filters. In the particular case of the Mid-Atlantic Ridge the neglect of the contribution of individual peaks leads to an erroneous estimate of the filtering properties of the massif.

scholarly journals Variability at Intermediate Depths at the Equator in the Atlantic Ocean in 2000–06: Annual Cycle, Equatorial Deep Jets, and Intraseasonal Meridional Velocity Fluctuations

2008 ◽  
Vol 38 (8) ◽  
pp. 1794-1806 ◽  
Author(s):  
Lucia Bunge ◽  
Christine Provost ◽  
Bach Lien Hua ◽  
Annie Kartavtseff
Keyword(s):  
Plane Wave ◽  
Velocity Component ◽  
Low Frequency ◽  
Velocity Amplitude ◽  
Meridional Velocity ◽  
Vertical Scale ◽  
Mid Atlantic Ridge ◽  
Phase Propagation ◽  
Interannual Fluctuations ◽  
Vertical Scales

Abstract Time series of high vertical resolution current meter measurements between 600-m and 1800-m depths on the equator in the Atlantic were obtained at two locations, 10° and 23°W. The measurements have a time span of almost 7 years (2000–06) and provide insights into the temporal scales and vertical structure of variability at intermediate depths. Variability in the zonal velocity component records is dominated by semiannual, annual, and interannual fluctuations. At semiannual and annual periodicities, vertical scales are large, on the order of 2000 stretched meters (sm), and show upward phase propagation. In contrast, interannual variability is associated with small vertical scale flows, called equatorial deep jets (EDJs), presenting downward phase propagation most of the time. Fitting a plane wave to these small vertical-scale flows leads to velocity amplitude, vertical scale, and temporal scale estimates of 8 (normalized) cm s−1, 440 sm, and 4.4 yr. However, this plane wave cannot explain all the variability presenting small vertical scales. Indeed, the data suggest that, along with a seasonal cycle of much larger vertical scale, different features with EDJ vertical scale coexist, with the possibility of a semipermanent eastward jet at around 1500 sm. Variability in the meridional velocity component is dominated by intraseasonal fluctuations. In addition, at 23°W, the meridional component shows low-frequency flows that may be due to the interaction of zonal fluctuations with the Mid-Atlantic Ridge.

Modeling low-frequency reverberation near the Mid-Atlantic Ridge and comparison with ARSRP data

1997 ◽  
Vol 101 (5) ◽  
pp. 2555-2565 ◽  
Author(s):  
Jerald W. Caruthers ◽  
E. J. Yoerger ◽  
J. C. Novarini
Keyword(s):  
Low Frequency ◽  
Mid Atlantic Ridge

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

Lectin Binding to Human Breast Tumor Cells

1976 ◽  
Vol 34 ◽  
pp. 34-35
Author(s):  
Robert E. Nordquist ◽  
J. Hill Anglin ◽  
Michael P. Lerner
Keyword(s):  
Carcinoma Cell ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Low Frequency ◽  
Breast Carcinoma Cell Line ◽  
Human Breast ◽  
Human Breast Tumor ◽  
Duct Carcinoma ◽  
Specific Antigens ◽  
Ricin Agglutinin

A human breast carcinoma cell line (BOT-2) was derived from an infiltrating duct carcinoma (1). These cells were shown to have antigens that selectively bound antibodies from breast cancer patient sera (2). Furthermore, these tumor specific antigens could be removed from the living cells by low frequency sonication and have been partially characterized (3). These proteins have been shown to be around 100,000 MW and contain approximately 6% hexose and hexosamines. However, only the hexosamines appear to be available for lectin binding. This study was designed to use Concanavalin A (Con A) and Ricinus Communis (Ricin) agglutinin for the topagraphical localization of D-mannopyranosyl or glucopyranosyl and D-galactopyranosyl or DN- acetyl glactopyranosyl configurations on BOT-2 cell surfaces.

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