Development of an Arctic Low Frequency Ambient Noise Model

• Main Authors: Bourke, Robert H, Wilson, James H
• Other Authors: NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF OCEANOGRAPHY
• Format: Text
• Language: English
• Published: 2000
• Subjects: Physical and Dynamic Oceanography; Snow; Ice and Permafrost; Acoustics; Radiofrequency Wave Propagation; *AMBIENT NOISE; *ARCTIC OCEAN; *LOW FREQUENCY; *SEA ICE; MODELS; PREDICTIONS; STORMS; STRESSES; INTERNAL STRESSES; ICE CANOPIES; CONVERGENT ATMOSPHERIC FORCING; ENERGY DISSIPATION RATE; RIDGE BUILDING; PIPIS(POLAR ICE PREDICTION SYSTEM); Arctic; Arctic Ocean; Ice; permafrost; Sea ice; ice covered waters
• Online Access: http://www.dtic.mil/docs/citations/ADA609743; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA609743

Our long-term goal is to develop a low frequency ambient noise model capable of predicting extreme (loud/quiet) noise events in Arctic ice-covered waters due to the presence or absence of storms. We wish to determine the internal stress of the ice canopy covering the Arctic ocean due to convergent atmospheric forcing and relate this to energy dissipation rate due to ridge building, the major source of ambient noise in the frequency regime under consideration. At our request the Navy's Polar Ice Prediction System (PIPIS) has been modified to produce daily plots of energy dissipation rate over the ice-covered Arctic for the one-year period of the SHEBA experiment. We have analyzed ambient noise (AN) data from two ice-mounted buoys inserted near the SHEBA site and related changes in AN to changes in energy dissipation rate to test our hypothesis that energy dissipation, due to intense ice fracturing (ridge building) caused by migrating polar storms, is related to the source level density of the measured ambient noise. We have used high resolution differential radar images (RGPS) to corroborate the change in ice structure with changes in atmospheric forcing and ambient noise.