Ocean‐basin scale inversion of reverberation data.

1992 ◽  
Vol 91 (4) ◽  
pp. 2344-2344
Author(s):  
N. C. Makris ◽  
J. M. Berkson ◽  
W. A. Kuperman ◽  
J. S. Perkins
Keyword(s):  
Ocean Basin ◽  
Basin Scale

Spatial covariation in survival rates of Northeast Pacific pink salmon (Oncorhynchus gorbuscha)

2001 ◽  
Vol 58 (8) ◽  
pp. 1501-1515 ◽  
Author(s):  
Brian J Pyper ◽  
Franz J Mueter ◽  
Randall M Peterman ◽  
David J Blackbourn ◽  
Chris C Wood
Keyword(s):  
Spatial Scales ◽  
Pink Salmon ◽  
Survival Rates ◽  
Ocean Basin ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Geographical Regions ◽  
Basin Scale ◽  
Stock Recruitment ◽  
Best Fit

We examined spatial patterns of covariation in indices of survival rate (residuals from the best-fit stock- recruitment curve) across four decades among 43 wild pink salmon (Oncorhynchus gorbuscha) stocks from 14 geographical regions in Washington, British Columbia, and Alaska. We found strong evidence of positive covariation among stocks within each region and between certain adjacent regions (e.g., correlations from 0.3 to 0.7) but no evidence of covariation between stocks of distant regions (e.g., separated by 1000 km or more). This suggests that important environmental processes affecting temporal variation in survival rates of pink salmon from spawners to recruits operate at regional spatial scales rather than at the larger ocean basin scale. Based on limited fry abundance data, we found that this covariation in spawner-to-recruit survival rates may be strongly influenced by marine processes.

Deep diving with Clio

2020 ◽  
Vol 5 (48) ◽  
pp. eabf1499
Author(s):  
Jnaneshwar Das ◽  
Elizabeth Trembath-Reichert
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Underwater Vehicle ◽  
Ocean Basin ◽  
Deep Diving ◽  
Basin Scale

An autonomous underwater vehicle, named Clio, can sample ocean basin–scale biogeochemistry at depths up to 6000 meters.

scholarly journals Transport by deep convection in basin-scale geostrophic circulation: turbulence-resolving simulations

2019 ◽  
Vol 865 ◽  
pp. 681-719
Author(s):  
Catherine A. Vreugdenhil ◽  
Bishakhdatta Gayen ◽  
Ross W. Griffiths
Keyword(s):  
Boundary Layer ◽  
Thermal Boundary Layer ◽  
Large Scale ◽  
Deep Convection ◽  
Ocean Basin ◽  
Open Ocean ◽  
Small Scale ◽  
Large Scale Circulation ◽  
Buoyancy Forcing ◽  
Basin Scale

Direct numerical simulations are used to investigate the nature of fully resolved small-scale convection and its role in large-scale circulation in a rotating $f$-plane rectangular basin with imposed surface temperature difference. The large-scale circulation has a horizontal geostrophic component and a deep vertical overturning. This paper focuses on convective circulation with no wind stress, and buoyancy forcing sufficiently strong to ensure turbulent convection within the thermal boundary layer (horizontal Rayleigh numbers $Ra\approx 10^{12}{-}10^{13}$). The dynamics are found to depend on the value of a convective Rossby number, $Ro_{\unicode[STIX]{x0394}T}$, which represents the strength of buoyancy forcing relative to Coriolis forces. Vertical convection shifts from a mean endwall plume under weak rotation ($Ro_{\unicode[STIX]{x0394}T}>10^{-1}$) to ‘open ocean’ chimney convection plus mean vertical plumes at the side boundaries under strong rotation ($Ro_{\unicode[STIX]{x0394}T}<10^{-1}$). The overall heat throughput, horizontal gyre transport and zonally integrated overturning transport are then consistent with scaling predictions for flow constrained by thermal wind balance in the thermal boundary layer coupled to vertical advection–diffusion balance in the boundary layer. For small Rossby numbers relevant to circulation in an ocean basin, vertical heat transport from the surface layer into the deep interior occurs mostly in ‘open ocean’ chimney convection while most vertical mass transport is against the side boundaries. Both heat throughput and the mean circulation (in geostrophic gyres, boundary currents and overturning) are reduced by geostrophic constraints.

scholarly journals Reducing bias due to noise and attenuation in open-ocean echo integration data

2015 ◽  
Vol 72 (8) ◽  
pp. 2482-2493 ◽  
Author(s):  
Tim E. Ryan ◽  
Ryan A. Downie ◽  
Rudy J. Kloser ◽  
Gordon Keith
Keyword(s):  
Full Range ◽  
Ocean Basin ◽  
Open Ocean ◽  
Weather Extremes ◽  
Processing Efficiency ◽  
Acoustic Data ◽  
Basin Scale ◽  
Backscattering Strength ◽  
Integration Data

Abstract Measurements of mean volume backscattering strength (Sv, dB re 1 m−1) at ocean-basin scale were made using 38-kHz hull-mounted echosounders on ships of opportunity as part of Australia's Integrated Marine Observing System. The data were collected on vessels of various designs, none of which were purposely built for collecting high-quality acoustic data. A full range of weather extremes affected the quality of the data and could cause large biases in Sv. To remove first-order biases and improve processing efficiency, a sequence of new and existing data processing filters were applied in a semi-automated procedure. These filters were designed to mitigate the effects of three types of noise: impulsive (less than one ping), transient (multiple pings), and background (hours or longer). A filter was also applied to identify signals that were attenuated by air bubbles beneath the transducer. These filters were applied to data from transits across the Southwest Pacific, Indian, and Southern Oceans to produce quality-controlled Sv datasets that are now available from a publicly accessible repository. These filters may be relevant to other open-ocean acoustic observing endeavours, and one or more could be used to mitigate bias in data from a range of acoustic applications.

scholarly journals Acoustic observations of micronekton fish on the scale of an ocean basin: potential and challenges

2009 ◽  
Vol 66 (6) ◽  
pp. 998-1006 ◽  
Author(s):  
Rudy J. Kloser ◽  
Tim E. Ryan ◽  
Jock W. Young ◽  
Mark E. Lewis
Keyword(s):  
Fishery Management ◽  
Size Structure ◽  
Acoustic Scattering ◽  
Ocean Basin ◽  
Fishing Vessel ◽  
Large Spatial Scale ◽  
Top Predators ◽  
Basin Scale ◽  
Acoustic Methods ◽  
Marine Planning

Abstract Kloser, R. J., Ryan, T. E., Young, J. W., and Lewis, M. E. 2009. Acoustic observations of micronekton fish on the scale of an ocean basin: potential and challenges. – ICES Journal of Marine Science, 66: 998–1006. Acoustic methods of characterizing micronekton communities (∼2 to 20 cm length) on the scale of an ocean basin could provide valuable inputs to ecosystem-based fishery management, marine planning, and monitoring the effects of climate change. The micronekton fish are important forage for top predators (e.g. tunas), and information on their diversity, distribution, size-structure, and abundance is needed to increase accuracy of top-predator distribution and abundance predictions. At the scale of an ocean basin, four years of Tasman Sea transects using a fishing vessel provide fine-scale maps of acoustic backscatter at 38 kHz that reveal detailed spatial patterns and structure to depths of 1200 m. Research-vessel data provide detailed biodiversity, density, size structure, and acoustic-scattering information from depth-stratified net sampling and a lowered acoustic probe. Wet-weight biomass estimates of the micronekton fish in the region vary considerably by a factor of 5–58 between acoustics (16–29 g m−2), nets (1.6 g m−2), and large spatial-scale, ecological models (0.5–3 g m−2). We demonstrate the potential and challenges of an acoustic basin-scale, fishing-vessel monitoring programme, including optical and net sensing, which could assist in characterizing the biodiversity, distribution, and biomass of the micronekton fish.

scholarly journals A novel approach reveals high zooplankton standing stock deep in the sea

2016 ◽  
Author(s):  
Alexander Vereshchaka ◽  
Galina Abyzova ◽  
Anastasia Lunina ◽  
Eteri Musaeva ◽  
Tracey T. Sutton
Keyword(s):  
Standing Stock ◽  
World Ocean ◽  
Deep Ocean ◽  
Biogeochemical Cycling ◽  
Ocean Basin ◽  
Zooplankton Biomass ◽  
Ocean Dynamics ◽  
Novel Approach ◽  
Basin Scale

Abstract. In a changing ocean there is a critical need to understand global biogeochemical cycling, particularly regarding carbon. We have made strides in understanding upper ocean dynamics, but the deep ocean interior (> 1000 m) is still largely unknown, despite representing the overwhelming majority of Earth's biosphere. Here we present a method for estimating deep-pelagic zooplankton biomass on an ocean-basin scale. In so doing we have made several new discoveries about the Atlantic, which likely apply to the World Ocean. First, zooplankton biomass in the upper bathypelagic domain is higher than expected, representing an inverted biomass pyramid. Second, the majority of this biomass comprises macroplanktonic shrimps, which have been historically underestimated. These findings, coupled with recent findings of increased global deep-pelagic fish biomass, revise our perspective on the role of the deep-pelagic fauna in oceanic biogeochemical cycling.

Ocean-Basin Scale Inversion of Reverberation Data

1993 ◽  
pp. 195-201
Author(s):  
N. C. Makris ◽  
J. M. Berkson ◽  
W. A. Kuperman ◽  
J. S. Perkins
Keyword(s):  
Ocean Basin ◽  
Basin Scale

scholarly journals Quantifying humpback whale song sequences to understand the dynamics of song exchange at the ocean basin scale

2013 ◽  
Vol 133 (1) ◽  
pp. 560-569 ◽  
Author(s):  
Ellen C. Garland ◽  
Michael J. Noad ◽  
Anne W. Goldizen ◽  
Matthew S. Lilley ◽  
Melinda L. Rekdahl ◽  
...  
Keyword(s):  
Humpback Whale ◽  
Ocean Basin ◽  
Basin Scale

A link between male sperm whales, Physeter macrocephalus, of the Azores and Norway

2012 ◽  
Vol 92 (8) ◽  
pp. 1751-1756 ◽  
Author(s):  
Lisa Steiner ◽  
Luca Lamoni ◽  
Marta Acosta Plata ◽  
Silje-Kristin Jensen ◽  
Erland Lettevall ◽  
...  
Keyword(s):  
Nova Scotia ◽  
North Atlantic ◽  
Ocean Basin ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Photo Identification ◽  
The North ◽  
Male Sperm ◽  
Basin Scale ◽  
The North Atlantic

Little is known about the movements of male sperm whales, Physeter macrocephalus, in the North Atlantic. Recoveries of traditional harpoons and tags during commercial whaling indicated movements from Nova Scotia to Spain and from the Azores to Iceland and Spain. We compared collections of photo-identification images from different areas using the North Atlantic and Mediterranean Sperm Whale Catalogue and the Eurphlukes Phlex/Match programs. The largest collections of identified males (number of individuals, start and end date for data collection shown in parentheses) are for the Azores (297, 1987–2008), Andenes (375, 1988–1996 and 2008), Tromsø (84, 2005–2008). There were six matches between Andenes and Tromsø (~25 nm), with three of these re-sighted in multiple years and three photo-identification matches from the Azores to Norway (~2400 nm). In all cases individuals first photographed in the Azores (in 1993, 1999 and 2003) were matched to images collected later in Tromsø (in 2007 and 2008). In 1997 a photo-identification image from Andenes matched a male stranded on the west coast of Ireland. No matches were made to images in smaller collections from Iceland, Nova Scotia, Greenland, Dominica, Guadeloupe, Gulf of Mexico and the Mediterranean. These findings show the value of data collected from whale watching vessels and the importance of collaboration between groups to allow investigation on an ocean basin scale. It is hoped that with the coordinated collection of more images from around the Atlantic, further insight might be gained into the movements of these widely ranging animals.

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