Accession Number : AD0763662

Title :   Long Range Acoustic Transmission Loss in the Marginal Ice Zone North of Iceland,

Corporate Author : NAVAL ORDNANCE LAB WHITE OAK MD

Personal Author(s) : Bradley,David L. ; Colvin,Gabriel M.

Report Date : 21 APR 1973

Pagination or Media Count : 33

Abstract : Long range acoustic transmission loss measurements were made in the marginal ice zone north of Iceland in the late winter time period. The measurements were obtained with the use of two aircraft, one flying prearranged tracks dropping standard U.S. Navy explosive sound signals at timed intervals, the second aircraft loitering in a fixed area to monitor modified, calibrated sonobuoys, which were deployed to receive the incoming shot arrivals. Two distinct transmission loss tracks were flown and subsequently analyzed, one an ice-free track, the second ice-covered. Transmission loss data is presented for selected octave bands together with some abbreviated comparisons with data obtained in the deep arctic basins. The general conclusion to be drawn from this measurement program is that for similar refractive conditions, the acoustic transmission loss is higher over an ice-covered path then it is over an open water path for the frequency range of 63 Hz to 2000 Hz. (Author)

Descriptors :   (*SEA ICE, *SOUND TRANSMISSION), UNDERWATER SOUND, REFRACTION, ATTENUATION, GREENLAND SEA

Subject Categories : Physical and Dynamic Oceanography
      Snow, Ice and Permafrost

Distribution Statement : APPROVED FOR PUBLIC RELEASE