Accession Number:

AD1031024

Title:

Inter-Annual Variability of the Acoustic Propagation in the Mediterranean Sea Identified from a Synoptic Monthly Gridded Database as Compared with GDEM

Personal Author(s):

Corporate Author:

NAVAL POSTGRADUATE SCHOOL MONTEREY CA MONTEREY United States

Report Date:

2016-12-01

Abstract:

The primary area of this research is to identify inter-annual variability of acoustic propagation in the Mediterranean Sea through comparison of sound speed profiles obtained from the synoptic monthly gridded World Ocean Database SMD-WOD and Generalized Digital Environmental Model GDEM temperature T and salinity S data. The SMG-WOD for the region of interest in this study has 0.250.25 horizontal resolutions, 28 vertical levels from the surface to 3000-meter depth, one-month temporal increment from January 1960 to December 2014. It provides the long-term spatial and temporal variability of the T, S and sound speed profile data. However, the GDEM offers climatological monthly mean T, S data with 0.25 horizontal resolution and 78 vertical depths from the surface to 6600 meters. Five distinct points were chosen in order to model acoustic propagation to account for significant differences in mean salinity, temperature vertical profiles and bottom sediments between sub-basins. Overall, we found that the Levantine Surface Water LSW has the highest spiciness among the all water masses. We analyzed that transmission loss TL for each decade, and we found that there are inter-annual TL variabilities. TL does not show high inter-annual variabilities over convergence zone paths however, it shows high inter-annual variability on surface duct, bottom bounce and sound channels.

Descriptive Note:

Technical Report

Pages:

0169

Communities Of Interest:

Distribution Statement:

Approved For Public Release;

File Size:

15.52MB