ADCP Measurements from the ICESHELF 94 Experiment.
The ICESHELF 94 Experiment was conducted during April of 1994 from an ice camp in the Lincoln Sea at approximately 84 N, 63 W. An Acoustic Doppler Current Profiler (ADCP) was operated at the camp from 8 to 24 April in order to characterize the internal wave field at the site. The ADCP was suspended...
Main Authors: | , |
---|---|
Other Authors: | |
Format: | Text |
Language: | English |
Published: |
1995
|
Subjects: | |
Online Access: | http://www.dtic.mil/docs/citations/ADA302498 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA302498 |
id |
ftdtic:ADA302498 |
---|---|
record_format |
openpolar |
spelling |
ftdtic:ADA302498 2023-05-15T15:17:54+02:00 ADCP Measurements from the ICESHELF 94 Experiment. Plueddemann, Albert J. Galbraith, Nancy R. WOODS HOLE OCEANOGRAPHIC INSTITUTION MA 1995-09 text/html http://www.dtic.mil/docs/citations/ADA302498 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA302498 en eng http://www.dtic.mil/docs/citations/ADA302498 APPROVED FOR PUBLIC RELEASE DTIC AND NTIS Physical and Dynamic Oceanography Acoustic Detection and Detectors *OCEAN CURRENTS *UNDERWATER ACOUSTICS *SEA ICE VELOCITY OCEAN WAVES OCEAN SURFACE ACOUSTIC WAVES COMPARISON SIGNAL TO NOISE RATIO TIME SERIES ANALYSIS ACOUSTIC DETECTION BACKSCATTERING DEPTH OCEANOGRAPHIC DATA CONTINENTAL SHELVES PROFILES MIXED LAYER(MARINE) SALINITY SONAR ECHOES ACOUSTIC DATA SONAR TRANSDUCERS DIURNAL VARIATIONS INTERNAL WAVES DOPPLER EFFECT OCEAN TIDES ARCTIC OCEAN ADCP(ACOUSTIC DOPPLER CURRENT PROFILER) Text 1995 ftdtic 2016-02-19T13:09:25Z The ICESHELF 94 Experiment was conducted during April of 1994 from an ice camp in the Lincoln Sea at approximately 84 N, 63 W. An Acoustic Doppler Current Profiler (ADCP) was operated at the camp from 8 to 24 April in order to characterize the internal wave field at the site. The ADCP was suspended below the ice with transducers facing downwards from a depth of 12 m. This report describes the ADCP configuration and presents the raw data recorded by the ADCP. The processing steps involved in computing horizontal velocities in geographic coordinates from the raw data are described, and time series and spectra of the resulting velocity data are presented. Horizontal velocities of good quality (estimated precision of about 1 cm per second) were obtained between 27.7 m and 137.0 m depth with 7.8 m resolution. Data were obtained at five minute intervals, but averaged to 1 hr during processing to suppress instrument noise. Spectra show the velocity field to be dominated by variance at semi-diurnal frequency, with a maximum in energy between 50 and 110 m depth. The semi-diurnal tidal frequency (M2 = 0.0805 cph) cannot be distinguished from the local inertial frequency (f = 0.0829 cph) in the records. Maximum amplitudes of 8 to 10cm per second were seen near 80 m depth. Velocities from an InterOcean S4 current meter deployed at the same site were compared to those from the ADCP. Typical comparisons showed component velocity differences with means of less than 0.5 cm per second and standard deviations from 1.0 to 1.5 cm per second. The largest differences were associated with peaks in the semi-diurnal oscillations, with the S4 underspeeding relative to the ADCP. Text Arctic Arctic Ocean Lincoln Sea Sea ice Defense Technical Information Center: DTIC Technical Reports database Arctic Arctic Ocean |
institution |
Open Polar |
collection |
Defense Technical Information Center: DTIC Technical Reports database |
op_collection_id |
ftdtic |
language |
English |
topic |
Physical and Dynamic Oceanography Acoustic Detection and Detectors *OCEAN CURRENTS *UNDERWATER ACOUSTICS *SEA ICE VELOCITY OCEAN WAVES OCEAN SURFACE ACOUSTIC WAVES COMPARISON SIGNAL TO NOISE RATIO TIME SERIES ANALYSIS ACOUSTIC DETECTION BACKSCATTERING DEPTH OCEANOGRAPHIC DATA CONTINENTAL SHELVES PROFILES MIXED LAYER(MARINE) SALINITY SONAR ECHOES ACOUSTIC DATA SONAR TRANSDUCERS DIURNAL VARIATIONS INTERNAL WAVES DOPPLER EFFECT OCEAN TIDES ARCTIC OCEAN ADCP(ACOUSTIC DOPPLER CURRENT PROFILER) |
spellingShingle |
Physical and Dynamic Oceanography Acoustic Detection and Detectors *OCEAN CURRENTS *UNDERWATER ACOUSTICS *SEA ICE VELOCITY OCEAN WAVES OCEAN SURFACE ACOUSTIC WAVES COMPARISON SIGNAL TO NOISE RATIO TIME SERIES ANALYSIS ACOUSTIC DETECTION BACKSCATTERING DEPTH OCEANOGRAPHIC DATA CONTINENTAL SHELVES PROFILES MIXED LAYER(MARINE) SALINITY SONAR ECHOES ACOUSTIC DATA SONAR TRANSDUCERS DIURNAL VARIATIONS INTERNAL WAVES DOPPLER EFFECT OCEAN TIDES ARCTIC OCEAN ADCP(ACOUSTIC DOPPLER CURRENT PROFILER) Plueddemann, Albert J. Galbraith, Nancy R. ADCP Measurements from the ICESHELF 94 Experiment. |
topic_facet |
Physical and Dynamic Oceanography Acoustic Detection and Detectors *OCEAN CURRENTS *UNDERWATER ACOUSTICS *SEA ICE VELOCITY OCEAN WAVES OCEAN SURFACE ACOUSTIC WAVES COMPARISON SIGNAL TO NOISE RATIO TIME SERIES ANALYSIS ACOUSTIC DETECTION BACKSCATTERING DEPTH OCEANOGRAPHIC DATA CONTINENTAL SHELVES PROFILES MIXED LAYER(MARINE) SALINITY SONAR ECHOES ACOUSTIC DATA SONAR TRANSDUCERS DIURNAL VARIATIONS INTERNAL WAVES DOPPLER EFFECT OCEAN TIDES ARCTIC OCEAN ADCP(ACOUSTIC DOPPLER CURRENT PROFILER) |
description |
The ICESHELF 94 Experiment was conducted during April of 1994 from an ice camp in the Lincoln Sea at approximately 84 N, 63 W. An Acoustic Doppler Current Profiler (ADCP) was operated at the camp from 8 to 24 April in order to characterize the internal wave field at the site. The ADCP was suspended below the ice with transducers facing downwards from a depth of 12 m. This report describes the ADCP configuration and presents the raw data recorded by the ADCP. The processing steps involved in computing horizontal velocities in geographic coordinates from the raw data are described, and time series and spectra of the resulting velocity data are presented. Horizontal velocities of good quality (estimated precision of about 1 cm per second) were obtained between 27.7 m and 137.0 m depth with 7.8 m resolution. Data were obtained at five minute intervals, but averaged to 1 hr during processing to suppress instrument noise. Spectra show the velocity field to be dominated by variance at semi-diurnal frequency, with a maximum in energy between 50 and 110 m depth. The semi-diurnal tidal frequency (M2 = 0.0805 cph) cannot be distinguished from the local inertial frequency (f = 0.0829 cph) in the records. Maximum amplitudes of 8 to 10cm per second were seen near 80 m depth. Velocities from an InterOcean S4 current meter deployed at the same site were compared to those from the ADCP. Typical comparisons showed component velocity differences with means of less than 0.5 cm per second and standard deviations from 1.0 to 1.5 cm per second. The largest differences were associated with peaks in the semi-diurnal oscillations, with the S4 underspeeding relative to the ADCP. |
author2 |
WOODS HOLE OCEANOGRAPHIC INSTITUTION MA |
format |
Text |
author |
Plueddemann, Albert J. Galbraith, Nancy R. |
author_facet |
Plueddemann, Albert J. Galbraith, Nancy R. |
author_sort |
Plueddemann, Albert J. |
title |
ADCP Measurements from the ICESHELF 94 Experiment. |
title_short |
ADCP Measurements from the ICESHELF 94 Experiment. |
title_full |
ADCP Measurements from the ICESHELF 94 Experiment. |
title_fullStr |
ADCP Measurements from the ICESHELF 94 Experiment. |
title_full_unstemmed |
ADCP Measurements from the ICESHELF 94 Experiment. |
title_sort |
adcp measurements from the iceshelf 94 experiment. |
publishDate |
1995 |
url |
http://www.dtic.mil/docs/citations/ADA302498 http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA302498 |
geographic |
Arctic Arctic Ocean |
geographic_facet |
Arctic Arctic Ocean |
genre |
Arctic Arctic Ocean Lincoln Sea Sea ice |
genre_facet |
Arctic Arctic Ocean Lincoln Sea Sea ice |
op_source |
DTIC AND NTIS |
op_relation |
http://www.dtic.mil/docs/citations/ADA302498 |
op_rights |
APPROVED FOR PUBLIC RELEASE |
_version_ |
1766348153738493952 |