Fig. 5. Transmission loss as a function of frequency and range for different source and receiver depths. In these cases the ice cover is 2m thick and the surface duct depth is 100 m. SD is source depth and RD is receiver depth.
band limited frequency domain than for other frequencies, this domain is called the optimum frequency domain of propagation.
Comparing the different cases in Fig. 5 show that the optimum frequency of propagation is most sensitive to the depth of the receiver relative to the surface duct and less sensitive to the position of the source. The optimum frequency of propagation increases to 65 Hz for source and receivers positioned within the surface duct. If the receiver is positioned below the duct the optimum frequency of propagation is between 25-30 Hz, which is close to the measured maximum lobe of the ambient noise frequency. This will have consequences for selecting the best frequency for long range monitoring in the Arctic Basin. By selecting a source frequency between 30-40 Hz the
