Observations of thermohaline sound-speed structure induced by internal waves and spice in the summer 2015 Canada Basin marginal ice zone

The Arctic seas are in a period of transition as they adjust to stimuli from anthropogenic climate change. The acoustic response to this adjustment is of fundamental interest, as acoustics provide an important means for Arctic remote sensing, communication and navigation, and there are important bio...

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Published in:Elementa: Science of the Anthropocene
Main Authors: Dominic DiMaggio, John A. Colosi, John Joseph, Annalise Pearson, Peter F. Worcester, Matthew A. Dzieciuch
Format: Article in Journal/Newspaper
Language:English
Published: BioOne 2018
Subjects:
geo
Online Access:https://doi.org/10.1525/elementa.186
https://doaj.org/article/6226d9ab16d74da2a254da41abdf69ff
id fttriple:oai:gotriple.eu:oai:doaj.org/article:6226d9ab16d74da2a254da41abdf69ff
record_format openpolar
spelling fttriple:oai:gotriple.eu:oai:doaj.org/article:6226d9ab16d74da2a254da41abdf69ff 2023-05-15T14:53:03+02:00 Observations of thermohaline sound-speed structure induced by internal waves and spice in the summer 2015 Canada Basin marginal ice zone Dominic DiMaggio John A. Colosi John Joseph Annalise Pearson Peter F. Worcester Matthew A. Dzieciuch 2018-04-01 https://doi.org/10.1525/elementa.186 https://doaj.org/article/6226d9ab16d74da2a254da41abdf69ff en eng BioOne 2325-1026 doi:10.1525/elementa.186 https://doaj.org/article/6226d9ab16d74da2a254da41abdf69ff undefined Elementa: Science of the Anthropocene, Vol 6, Iss 1 (2018) acoustics observations Arctic Ocean Canada Basin marginal ice zone geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2018 fttriple https://doi.org/10.1525/elementa.186 2023-01-22T19:28:45Z The Arctic seas are in a period of transition as they adjust to stimuli from anthropogenic climate change. The acoustic response to this adjustment is of fundamental interest, as acoustics provide an important means for Arctic remote sensing, communication and navigation, and there are important biological implications for marine mammals and other organisms that use sound. The Canada Basin Acoustic Propagation Experiment (CANAPE) is an effort to study Arctic acoustics; this paper reports on ocean sound-speed measurements from a pilot study undertaken between 30 July and 16 August 2015. Moored and shipborne observations of temperature and salinity were made in the upper 600 m of the ocean, allowing analysis along isopycnals (surfaces of constant density) to separate sound-speed structure due to internal-wave-induced vertical displacements from those originating from density-compensated temperature and salinity variations termed spice. Frequency spectra and vertical covariance functions were used to describe the space/time scales of displacements and spice. Internal-wave frequency spectra show a spectral slope much lower than the Garrett-Munk model, with the energy level roughly 4% of the standard Garrett-Munk value. Frequency spectra of spice show a form similar to the internal-wave spectra but with a slightly steeper spectral slope, presumably due to the horizontal advection of the spice by internal-wave currents. The root mean square sound-speed fluctuations from internal waves were small with values less than 0.1 m s–1. Spicy sound-speed fluctuations were much stronger, particularly in the upper 100 m where a maximum of 0.25 m s–1 was observed. Both processes have vertical decorrelation lengths less than 100 m. The observed strong variations in vertical and horizontal sound-speed structure will have significant impacts on acoustic applications, especially in the realm of communications, navigation, and remote sensing. Article in Journal/Newspaper Arctic Arctic Ocean canada basin Climate change Unknown Arctic Arctic Ocean Canada Munk ENVELOPE(-95.993,-95.993,55.979,55.979) Elementa: Science of the Anthropocene 6
institution Open Polar
collection Unknown
op_collection_id fttriple
language English
topic acoustics
observations
Arctic Ocean
Canada Basin
marginal ice zone
geo
envir
spellingShingle acoustics
observations
Arctic Ocean
Canada Basin
marginal ice zone
geo
envir
Dominic DiMaggio
John A. Colosi
John Joseph
Annalise Pearson
Peter F. Worcester
Matthew A. Dzieciuch
Observations of thermohaline sound-speed structure induced by internal waves and spice in the summer 2015 Canada Basin marginal ice zone
topic_facet acoustics
observations
Arctic Ocean
Canada Basin
marginal ice zone
geo
envir
description The Arctic seas are in a period of transition as they adjust to stimuli from anthropogenic climate change. The acoustic response to this adjustment is of fundamental interest, as acoustics provide an important means for Arctic remote sensing, communication and navigation, and there are important biological implications for marine mammals and other organisms that use sound. The Canada Basin Acoustic Propagation Experiment (CANAPE) is an effort to study Arctic acoustics; this paper reports on ocean sound-speed measurements from a pilot study undertaken between 30 July and 16 August 2015. Moored and shipborne observations of temperature and salinity were made in the upper 600 m of the ocean, allowing analysis along isopycnals (surfaces of constant density) to separate sound-speed structure due to internal-wave-induced vertical displacements from those originating from density-compensated temperature and salinity variations termed spice. Frequency spectra and vertical covariance functions were used to describe the space/time scales of displacements and spice. Internal-wave frequency spectra show a spectral slope much lower than the Garrett-Munk model, with the energy level roughly 4% of the standard Garrett-Munk value. Frequency spectra of spice show a form similar to the internal-wave spectra but with a slightly steeper spectral slope, presumably due to the horizontal advection of the spice by internal-wave currents. The root mean square sound-speed fluctuations from internal waves were small with values less than 0.1 m s–1. Spicy sound-speed fluctuations were much stronger, particularly in the upper 100 m where a maximum of 0.25 m s–1 was observed. Both processes have vertical decorrelation lengths less than 100 m. The observed strong variations in vertical and horizontal sound-speed structure will have significant impacts on acoustic applications, especially in the realm of communications, navigation, and remote sensing.
format Article in Journal/Newspaper
author Dominic DiMaggio
John A. Colosi
John Joseph
Annalise Pearson
Peter F. Worcester
Matthew A. Dzieciuch
author_facet Dominic DiMaggio
John A. Colosi
John Joseph
Annalise Pearson
Peter F. Worcester
Matthew A. Dzieciuch
author_sort Dominic DiMaggio
title Observations of thermohaline sound-speed structure induced by internal waves and spice in the summer 2015 Canada Basin marginal ice zone
title_short Observations of thermohaline sound-speed structure induced by internal waves and spice in the summer 2015 Canada Basin marginal ice zone
title_full Observations of thermohaline sound-speed structure induced by internal waves and spice in the summer 2015 Canada Basin marginal ice zone
title_fullStr Observations of thermohaline sound-speed structure induced by internal waves and spice in the summer 2015 Canada Basin marginal ice zone
title_full_unstemmed Observations of thermohaline sound-speed structure induced by internal waves and spice in the summer 2015 Canada Basin marginal ice zone
title_sort observations of thermohaline sound-speed structure induced by internal waves and spice in the summer 2015 canada basin marginal ice zone
publisher BioOne
publishDate 2018
url https://doi.org/10.1525/elementa.186
https://doaj.org/article/6226d9ab16d74da2a254da41abdf69ff
long_lat ENVELOPE(-95.993,-95.993,55.979,55.979)
geographic Arctic
Arctic Ocean
Canada
Munk
geographic_facet Arctic
Arctic Ocean
Canada
Munk
genre Arctic
Arctic Ocean
canada basin
Climate change
genre_facet Arctic
Arctic Ocean
canada basin
Climate change
op_source Elementa: Science of the Anthropocene, Vol 6, Iss 1 (2018)
op_relation 2325-1026
doi:10.1525/elementa.186
https://doaj.org/article/6226d9ab16d74da2a254da41abdf69ff
op_rights undefined
op_doi https://doi.org/10.1525/elementa.186
container_title Elementa: Science of the Anthropocene
container_volume 6
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