scholarly journals Fine-scale depth structure of pelagic communities throughout the global ocean based on acoustic sound scattering layers

2018 ◽  
Vol 598 ◽  
pp. 35-48 ◽  
Author(s):  
R Proud ◽  
MJ Cox ◽  
C Le Guen ◽  
AS Brierley
Keyword(s):  
Global Ocean ◽  
Fine Scale ◽  
Sound Scattering ◽  
Pelagic Communities

scholarly journals The Solomon Sea: its circulation, chemistry, geochemistry and biology explored during two oceanographic cruises

Elem Sci Anth ◽  
2017 ◽  
Vol 5 ◽  
Author(s):  
Alexandre Ganachaud ◽  
Sophie Cravatte ◽  
Janet Sprintall ◽  
Cyril Germineaud ◽  
Marion Alberty ◽  
...  
Keyword(s):  
Hot Spot ◽  
Current System ◽  
Warm Pool ◽  
The United States ◽  
Equatorial Region ◽  
Water Masses ◽  
Global Ocean ◽  
Western Boundary ◽  
Fine Scale ◽  
Wide Range

The semi-enclosed Solomon Sea in the southwestern tropical Pacific is on the pathway of a major oceanic circuit connecting the subtropics to the equator via energetic western boundary currents. Waters transiting through this area replenish the Pacific Warm Pool and ultimately feed the equatorial current system, in particular the equatorial undercurrent. In addition to dynamical transformations, water masses undergo nutrient and micronutrient enrichment when coming in contact with the coasts, impacting the productivity of the downstream equatorial region. Broadscale observing systems are not well suited for describing the fine-scale currents and water masses properties in the Solomon Sea, leaving it relatively unexplored. Two multidisciplinary oceanographic cruises were conducted in the Solomon Sea region, the first in July–August 2012 and the second in March 2014, by investigators from France and the United States. The experimental approach combined physical, chemical, geochemical and biogeochemical analyses, providing access to a wide range of space and time scales of the circulation. This collection of data allows describing the fine-scale structure of the currents and the water properties, transformations and mixing from the surface to the sill depth in the Solomon Sea and in the straits connecting it to the equator. Ocean-margin exchanges were documented through a comprehensive sampling of trace elements and isotopes as efficient tracers of natural fertilization processes. As air chemistry is largely impacted by the regional volcanic plumes, rainwater pH was also sampled. Dinitrogen fixation rates were measured and found to be among the highest in the global ocean, highlighting this region as a hot spot of nitrogen fixation. This study provides an overview of the climatic context during both cruises and the physical circulation and water masses properties. It provides a comprehensive description of all measurements made onboard, and presents preliminary results, aiming to serve as a reference for further physical, geochemical and biogeochemical studies.

scholarly journals Flight paths of seabirds soaring over the ocean surface enable measurement of fine-scale wind speed and direction

2016 ◽  
Vol 113 (32) ◽  
pp. 9039-9044 ◽  
Author(s):  
Yoshinari Yonehara ◽  
Yusuke Goto ◽  
Ken Yoda ◽  
Yutaka Watanuki ◽  
Lindsay C. Young ◽  
...  
Keyword(s):  
Wind Speed ◽  
Ocean Surface ◽  
Coastal Areas ◽  
Global Ocean ◽  
Fine Scale ◽  
Surface Winds ◽  
Ground Speed ◽  
Wide Range ◽  
Ocean Surface Winds ◽  
Wind Velocities

Ocean surface winds are an essential factor in understanding the physical interactions between the atmosphere and the ocean. Surface winds measured by satellite scatterometers and buoys cover most of the global ocean; however, there are still spatial and temporal gaps and finer-scale variations of wind that may be overlooked, particularly in coastal areas. Here, we show that flight paths of soaring seabirds can be used to estimate fine-scale (every 5 min, ∼5 km) ocean surface winds. Fine-scale global positioning system (GPS) positional data revealed that soaring seabirds flew tortuously and ground speed fluctuated presumably due to tail winds and head winds. Taking advantage of the ground speed difference in relation to flight direction, we reliably estimated wind speed and direction experienced by the birds. These bird-based wind velocities were significantly correlated with wind velocities estimated by satellite-borne scatterometers. Furthermore, extensive travel distances and flight duration of the seabirds enabled a wide range of high-resolution wind observations, especially in coastal areas. Our study suggests that seabirds provide a platform from which to measure ocean surface winds, potentially complementing conventional wind measurements by covering spatial and temporal measurement gaps.

High Resolution Stereography of Complementary Freeze-Fracture Replicas Reveals the Presence of Depressions Opposite Membrane Associated Particles of Split Membranes

1971 ◽  
Vol 29 ◽  
pp. 442-443
Author(s):  
Russell L. Steere
Keyword(s):  
High Resolution ◽  
Cardiac Muscle ◽  
Electron Micrographs ◽  
Chromic Acid ◽  
Freeze Fracture ◽  
Distilled Water ◽  
Fine Scale ◽  
Acid Cleaning ◽  
Cleaning Solution

Complementary replicas have revealed the fact that the two common faces observed in electron micrographs of freeze-fracture and freeze-etch specimens are complementary to each other and are thus the new faces of a split membrane rather than the original inner and outer surfaces (1, 2 and personal observations). The big question raised by published electron micrographs is why do we not see depressions in the complementary face opposite membrane-associated particles? Reports have appeared indicating that some depressions do appear but complementarity on such a fine scale has yet to be shown.Dog cardiac muscle was perfused with glutaraldehyde, washed in distilled water, then transferred to 30% glycerol (material furnished by Dr. Joaquim Sommer, Duke Univ., and VA Hospital, Durham, N.C.). Small strips were freeze-fractured in a Denton Vacuum DFE-2 Freeze-Etch Unit with complementary replica tooling. Replicas were cleaned in chromic acid cleaning solution, then washed in 4 changes of distilled water and mounted on opposite sides of the center wire of a Formvar-coated grid.

Sign in / Sign up

Export Citation Format

Share Document