ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Ocean response to a hurricane, part II : data tabulations and numerical modeling (2006)
    Woods Hole Oceanographic Institution
    Details
    Publication Date: 2022-05-25
    Description: Field observations of the ocean's forced stage response to three hurricanes, Norbert (1984), Josephine (1984) and Gloria (1985), are analyzed and presented in a storm-centered coordinate system. All three hurricanes had a non-dimensional speed of O(1) and produced a strongly rightward biased response of the ocean surface mixed layer (SML) transport and current. The maximum layer-averaged SML currents varried from 0.8 m S-1 in response to Josephine, which was a fairly weak hurricane, to 1.7 m S.l in response to Gloria, which was much stronger. In these two cases the current amplitude is set primarly by the strength of the wind stress and its efficiency of coupling with the SML current, and the depth of vertical mixing of the SML. The Norbert case (SML Burger number ≈ 1/2) was also affected by significant pressure-coupling with the thermocline that caused appreciable upwellng by inertial pumping and strong thermocline-depth currents, up to 0.3 m S-l, under the trailing edge of Norbert. The observed SML current has a vertical shear in the direction of the local wind of up to 0.01 S-l. This vertical shear causes the surface current to be larger than the layer-averaged SML current described above by typically 0.2 m S.l.
    Description: Funding was provided by the Office of Naval Research under grant No. N00014-89-J-I053.
    Keywords: Ocean models ; Wind-driven currents ; Aircraft measurements
    Repository Name: Woods Hole Open Access Server
    Type: Technical Report
    Format: 3034212 bytes
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 2
    facet.materialart.
    Unknown
    Segmentation and crustal structure of the western Mid-Atlantic Ridge flank, 25°25′–27°10′N and 0–29 m.y. (2013)
    American Geophysical Union
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © American Geophysical Union, 1997. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 102, no. B5 (1997): 10203–10223, doi:10.1029/96JB03896.
    Description: We conducted a detailed geological-geophysical survey of the west flank of the Mid-Atlantic Ridge between 25°25′N and 27°10′N and from the ridge axis out to 29 Ma crust, acquiring Hydrosweep multibeam bathymetry, HAWAII MR1 sidescan-sonar imagery, gravity, magnetics, and single-channel seismic reflection profiles. The survey covered all or part of nine spreading segments bounded by mostly nontransform, right-stepping discontinuities which are subparallel to flow lines but which migrated independently of one another. Some discontinuities alternated between small right- and left-stepping offsets or exhibited zero offset for up to 3–4 m.y. Despite these changes, the spreading segments have been long-lived and extend 20 m.y. or more across isochrons. A large shift (∼9°) in relative plate motion about 24–22 Ma caused significant changes in segmentation pattern. The nature of this plate-boundary response, together with the persistence of segments through periods of zero offset at their bounding discontinuities, suggest that the position and longevity of segments are controlled primarily by the subaxial position of buoyant mantle diapirs or focused zones of rising melt. Within segments, there are distinct differences in seafloor depth, morphology, residual mantle Bouguer gravity anomaly, and apparent crustal thickness between inside-corner and outside-corner crust. This demands fundamentally asymmetric crustal accretion and extension across the ridge axis, which we attribute to low-angle, detachment faulting near segment ends. Cyclic variations in residual gravity over the crossisochron run of segments also suggest crustal-thickness changes of at least 1–2 km every 2–3 m.y. These are interpreted to be caused by episodes of magmatic versus relatively amagmatic extension, controlled by retention and quasiperiodic release of melt from the upwelling mantle. Detachment faulting appears to be especially effective in exhuming lower crust to upper mantle at inside corners during relatively amagmatic episodes, creating crustal domes analogous to “turtleback” metamorphic core complexes that are formed by low-angle, detachment faulting in subaerial extensional environments.
    Description: This research was supported by ONR grants N00014-90-J-1621 and N00014-94-1-0466 and NSF grant OCE-9300708.
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 3
    facet.materialart.
    Unknown
    The physical structure and life history of cyclonic Gulf Stream ring, Allen (2018)
    Woods Hole Oceanographic Institution
    Details
    Publication Date: 2022-05-26
    Description: Also published as: Journal of Geophysical Research 84 (1979): 7727-7741
    Description: A cyclonic Gulf Stream ring, Allen, was followed over its life from September 1976 to April 1977 in the region north of Bermuda. Conductivity, temperature, and depth; expendable bathythermograph; and velocity profile measurements were made in Allen, and over the last 5 months of its life, satellite buoys were used to track continuously its movement. The measurements indicate that in December 1976 Allen split into two rings, a large one, Allen, and a small one, Arthur. Arthur moved rapidly eastward and coalesced with the Gulf Stream near the New England seamounts. Allen moved in a large clockwise loop; at the end of February 1977 it became attached to the Gulf Stream and reformed into a modified ring, smaller in size and faster in rotation . At the end of April 1977 the modified ring coalesced with the Gulf Stream and disappeared as it was advected downstream in the stream. The principal results of this study are that (I) the New England Seamount chain was a major influence in the genesis of Allen and on the trajectories of nearby rings; (2) while a free eddy, months after its formation, Allen evolved into a bi modal or peanut-shaped structure; (3) the bimodal structure ultimately bifurcated, spawning a new isolated eddy, denoted as Arthur, and a modified remnant, Allen; (4) the velocity field of Allen involved the whole water column, with bottom velocities of 10-15 em s- 1; (5) the barotropic velocity at the center of Allen (6 cm s-1 to NNW) was about equal to its translation velocity (4 cm s-1 to NW); (6) especially energetic inertial motions were seen at the center of Allen, and these may play a role in enhancing the stirring of water properties; (7) Allen survived several close encounters or entrainments with the Gulf Stream, proving that such encounters can be nonfatal to a ring; (8) the encounters appear to result in injections (exchanges) of water (momentum, heat, etc.) into the rings at an estimate rate of 106 m3 s-1 per ring; and (9) the behavior of Allen and Arthur was in contrast to the results of some other studies which have shown that rings generally drift slowly and passively southwestward.
    Description: Prepared for the Office of Naval Research under Contract N000 14-74-C-0262; NR 083-004 and for the National Science Foundation under Grants OCE 76-82059, DES 74-02783, and OCE 76-24605.
    Keywords: Eddies ; Oceanographic buoys
    Repository Name: Woods Hole Open Access Server
    Type: Technical Report
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 4
    facet.materialart.
    Unknown
    Performance of an absolute velocity profiler based on acoustic doppler and electromagnetic principles (2018)
    Woods Hole Oceanographic Institution
    Details
    Publication Date: 2022-05-26
    Description: This report describes the performance of a freely-falling velocity profiler called the Absolute Velocity Profiler (AVP) . The AVP is distinguishable from our previously developed velocity profiler the Electro-Magnetic Velocity Profiler (EMVP) in that acoustic Doppler measurements are used, to determine the reference velocity for the EMVP profiles. The AVP contains the essential measurements of the motional electric currents in the sea as implemented in the EMVP and in addition, collects acoustic Doppler measurements of frequencyshifted bottom echoes. The former measurements yield a profile of the horizontal components of velocity relative to a reference velocity, independent of depth, while the latter measurements determine the absolute velocity of the AVP vehicle with respect to the sea floor. The EM profile is obtained from the sea surface to bottom, and the acoustic Doppler measurements are made within about 300 m of the sea floor. The combination of the EM and acoustic Doppler measurements yields an absolute velocity profile throughout the water column. Performance analyses included in this report set method uncertainties of between 1 and 2 cm/s r.m.s. Measurements of temperature and its gradient are also made.
    Description: Prepared for the National Science Foundation, Office of the International Decade of Ocean Exploration under Grant OCE76-24605.
    Keywords: Doppler effect ; Electromagnetism ; Ocean currents ; Oceanographic instruments
    Repository Name: Woods Hole Open Access Server
    Type: Technical Report
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 5
    facet.materialart.
    Unknown
    Eddies, islands, and mixing (2018)
    Woods Hole Oceanographic Institution
    Details
    Publication Date: 2022-05-26
    Description: Also published as Journal of Geophysical Research, 83(C6), 1978, pp. 2921–2938
    Description: As part of a field study of the relation between fine scale and large‐scale variations of water properties in the western North Atlantic, the waters in the vicinity of Bermuda were investigated in detail. Previous work in the area had revealed regions of intense temperature fine structure confined to the sides of the island. Generally quieter levels of activity elsewhere in the midocean have suggested that significant mixing might only occur at the solid and fluid boundaries of the ocean. During the course of our investigation, two Gulf Stream rings were found in the vicinity of the island. The exchange of water between them caused three regions of strong alongshore flow. In these three areas we find elevated levels of temperature fine structure in the upper 800 m as measured by the variance in the temperature gradient normalized by the square of the mean temperature gradient over the interval. The normalized temperature variances on small scales (0.2–1 m) are most energetic in patches tightly bound to the island sides, whereas the fine structure on larger scales (5–25 m) is also energetic away from the island in a region of outflow. Velocity profiles show that vertical scales shorten as one approaches the island, and the energy increases in the counterclockwise component. There is no correlation evident between the shear measurements of the internal wave field and the intensity of the fine structure. Possible mechanisms for the production of fine structure are explored within the context of these observations.
    Description: This research was carried out with funding from the Office of Naval Research under contracts NOOOI4-74-C- 0262 NR083-004 (N .G.H. and T.B.S.) and the National Science Foundation under grant OCE74-19608 (E.J.K.).
    Keywords: Oceanic mixing ; Turbulence ; Ocean currents
    Repository Name: Woods Hole Open Access Server
    Type: Technical Report
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 6
    facet.materialart.
    Unknown
    Highly resolved observations and simulations of the ocean response to a hurricane (2010)
    American Geophysical Union
    Details
    Publication Date: 2022-05-26
    Description: Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 34 (2007): L13604, doi:10.1029/2007GL029679.
    Description: An autonomous, profiling float called EM-APEX was developed to provide a quantitative and comprehensive description of the ocean side of hurricane-ocean interaction. EM-APEX measures temperature, salinity and pressure to CTD quality and relative horizontal velocity with an electric field sensor. Three prototype floats were air-deployed into the upper ocean ahead of Hurricane Frances (2004). All worked properly and returned a highly resolved description of the upper ocean response to a category 4 hurricane. At a float launched 55 km to the right of the track, the hurricane generated large amplitude, inertially rotating velocity in the upper 120 m of the water column. Coincident with the hurricane passage there was intense vertical mixing that cooled the near surface layer by about 2.2°C. We find consistent model simulations of this event provided the wind stress is computed from the observed winds using a high wind-speed saturated drag coefficient.
    Description: The development of the EM-APEX float system was supported by the Office of Naval Research through SBIR contract N00014-03-C-0242 to Webb Research Corporation and with a subcontract to APL-UW.
    Keywords: Hurricane-ocean interaction ; Wind stress and inertial motions ; Hurricane wake ; Numerical upper ocean model ; Instruments and methods
    Repository Name: Woods Hole Open Access Server
    Type: Article
    Format: image/tiff
    Format: application/pdf
    Format: text/plain
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER (OA)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...