INCORPORATION OF ACOUSTIC NORMAL-MODE DATA INTO TOMOGRAPHIC INVERSIONS IN THE GREENLAND SEA

Acoustic normal mode group velocity data are extracted from tomographi c receptions in the Greenland Sea using a combination of spatial filte ring with data from a six-element hydrophone array and variable time w indowing. The mode group velocity data, together with ray travel time data, are used in inversions to obtain the range average sound speed p rofile. The modal data significantly improve near-surface resolution, which is where the largest oceanographic signals occur. Inverse result s using only acoustic data are consistent with point measurements, a S easoar section, and sparse conductivity-temperature-depth data.