Results 291 to 300 of about 57,296 (333)
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Transport measurements in the arctic ice-pack
Letters in Heat and Mass Transfer, 1980Abstract The characteristics of the Polar Pack are generally thought to have a large influence on terrestrial weather. Yet the environment of the sea ice and its dynamic response to the seasonal cycle, as well as to gradually changing average conditions, have received little study or transport modelling. A specific measurement program was devised and
Benjamin Gebhart, Tore Audunson
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Acoustically derived ice-fracture velocity in central Arctic pack ice
The Journal of the Acoustical Society of America, 2000Sounds radiated by fractures in Arctic ice (called acoustic events) are used to estimate fracture velocity. Both speed and orientation are obtained by measuring Doppler shifts induced by source motion. Data from the SIMI experiment of 1994 in the central Arctic are used in the frequency window 10 to 350 Hz.
Ira Dyer, Catherine Stamoulis
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HF radar observations of Arctic pack-ice breakup
IEEE Journal of Oceanic Engineering, 1986This paper describes the first reported high-resolution remote measurements of sea-ice velocities during the summer Arctic pack-ice breakup, made with a high-frequency (HF) radar system (CODAR, for Coastal Ocean Dynamics Applications Radar) located on Cross Island, Alaska. Each 36-min observation also gives the positions of the ice edge, the moving ice,
B. Lipa, R. Crissman, D. Barrick
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Vibrational Motion of Arctic Pack Ice,
1997Abstract : There are many physical mechanisms responsible for vibrations of sea, and they force motions in a very wide band of frequencies from less than 0.01 Hz to greater than 100 Hz. Detailed measurements of the vertical velocity in this frequency band were previously shown to be produced by gravity waves, ridging events and wind turbulence. In this
John Dugan +2 more
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Upwelling: Oceanic Structure at the Edge of the Arctic Ice Pack in Winter
Science, 1979Observations taken on an expedition into the Arctic Ocean north of Spitsbergen indicated the existence of a region of wind-driven upwelling along the edge of the ice pack. Models underestimate the 12-kilometer width of the upwelling region.
Johnny A. Johannessen +4 more
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Pack-ice studies in the Arctic Ocean
Journal of Geophysical Research, 1959The annual stratification of pack ice has been examined. Summer layers are formed either by arrested growth or by thin layers of fresh-water ice. The crystal structure and the salt content of the ice reflect the seasonal cycle. During the growth of ice a pronounced orientation of crystalline structure develops; it is determined by vertical as well as ...
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Low‐frequency vibrational motion of Arctic pack ice
Journal of Geophysical Research: Oceans, 1992The mechanisms responsible for vibrational motions of Arctic ice at frequencies below about 100 Hz are know to be a combination of wave types, namely, gravity waves, flexural waves, and a variety of acoustic and/or elastic waves. Surface motion measurements using geophones and accelerometers on multiyear pack ice are used to establish the energy level ...
R. L. DiMarco, J. P. Dugan, W. W. Martin
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Airborne laser profiling of the arctic pack ice
Remote Sensing of Environment, 1971Abstract Since 1964, airborne experiments over the Arctic pack ice have been conducted, on an opportunity basis, to test and evaluate the usefulness of various remote sensing systems for mapping and measuring sea ice conditions and features. This paper describes the results of an analysis of laser terrain profile data obtained with coincident ...
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Sea-ice algae in Arctic pack ice during late winter
Polar Biology, 2007Pack ice around Svalbard was sampled during the expedition ARK XIX/1 of RV “Polarstern” (March–April 2003) in order to determine environmental conditions, species composition and abundances of sea-ice algae and heterotrophic protists during late winter. As compared to other seasons, species diversity of algae (total 40 taxa) was not low, but abundances
Johanna Ikävalko +2 more
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Underwater Backscattering Strengths of Arctic Pack Ice
The Journal of the Acoustical Society of America, 1964The backscattering strengths under Arctic sea ice for octave bands between 12 cps and 4 kc/sec were measured, using explosive sound sources. The measurements were made from a camp established in April 1962 on broken and pressure-packed one-year ice over the Canada Deep.
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