AMBIENT NOISE MEASUREMENTS IN THE 200-300-HZ BAND FROM THE GREENLAND SEA TOMOGRAPHY EXPERIMENT

Ambient noise in the 200-300-Hz band was measured every four hours fro m Sept 1988 to Sept 1989 as part of the Greenland Sea tomography exper iment (GSP88). Four transceivers, located in the central Greenland Sea gyre, sampled the noise during a wide variety of ice, wind, and wave conditions, revealing large seasonal variations in the noise field. Th e environmental conditions were obtained mainly from large-scale remot e sensing and numerical modeling, i.e., operational meteorological for ecast models, surface wave models, and microwave and infrared satellit e imaging (for ice). To understand the noise field, a number of analys es were performed on the noise, wind, ice concentration, and wave-time series, including regressions, auto- and cross correlations, spectra, and acoustic propagation modeling. As a result, a number of environme ntal noise effects, particularly as related to ice edge noise, are obs erved. The results generally agree well with previous, shorter time pe riod process oriented studies which used remote sensing as well as in situ ice, wind, and wave measurements. It is seen that prediction of t he marginal ice zone (MIZ) noise field for a deep ocean region at the acoustic frequencies examined is feasible using large-scale environmen tal information.