Three-Dimensional Distribution of Sound Speed in the Iceland-Faeroe Area, Retrieved from a CTD Survey, Thermistor-Chain Measurements and Satellite SST Imagery

The three-dimensional variability of sound speed in the Iceland-Faeroe Frontal (IFF) region is investigated. Emphasis is put on the question, to what extend subsurface sound speed may be determined from space-borne remote sensing. Data from different sources are used: CTD survey and thermistor-chain...

Full description

Bibliographic Details
Main Authors: Essen, H. H., Sellschop, J.
Other Authors: SACLANT UNDERSEA RESEARCH CENTRE LA SPEZIA (ITALY)
Format: Text
Language:English
Published: 1994
Subjects:
Physical and Dynamic Oceanography
Acoustics
*OCEANOGRAPHIC DATA
*SOUND
VELOCITY
INFRARED DETECTION
NATO
TEMPERATURE
OCEAN SURFACE
METEOROLOGICAL SATELLITES
THREE DIMENSIONAL
THERMISTORS
INFRARED IMAGES
GULF STREAM
REMOTE DETECTION
OCEAN BOTTOM
FRONTS(OCEANOGRAPHY)
SATELLITE IMAGERY
ICELAND FAEROE FRONT
NATO FURNISHED
AVHRR(ADVANCED VERY HIGH RESOLUTION RADIOMETER)
NOAA(NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION)
Iceland
Online Access:http://www.dtic.mil/docs/citations/ADB197442
http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADB197442
Description
Summary:The three-dimensional variability of sound speed in the Iceland-Faeroe Frontal (IFF) region is investigated. Emphasis is put on the question, to what extend subsurface sound speed may be determined from space-borne remote sensing. Data from different sources are used: CTD survey and thermistor-chain measurements as ground truth and satellite infrared imagery. Most of the data are temperatures which, for the area under consideration, quite accurately determine the sound speed. From the subsurface data it is shown that the vertical sound-speed profiles can be decomposed into empirical orthogonal eigenfunctions (EOFs), with the first two already accounting for 97% of the variance. High correlation of the first- and second-order EOF amplitudes is found with sea-surface dynamic height, and for the first-order EOF amplitude with sea-surface temperature (SST). The latter relation is used successfully to determine subsurface sound speeds from satellite-measured SSTs. Due to the resolution of the satellite data, horizontal scales are overestimated, and due to the availability of only the first-order EOF amplitude for the construction of sound-speed profiles, a too high vertical correlation is introduced. To overcome these problems, for the purpose of acoustic modelling, a theoretical three-dimensional sound-speed model is developed, based on the EOF decomposition. The EOF amplitudes contain the analytically described front and random portions represented by a finite moving average process.

Similar Items