Analysis and simulation of acoustic propagation affected by thermocline in deep water based on Argo data

Based on gridded Argo data, the distribution feature of thermocline in a small sea area to south of Japan is analyzed, and the results of which show that the double thermocline structure of permanent and seasonal thermocline are obvious. Then the UMPE acoustic model is used to analyze and simulate the impact of thermocline on acoustic transmission loss. The results show that: two sound speed profiles with the same changing trends result in the same transmission loss; when the source is put at the small depth in summer, the TL is great in the small circle area with the source as the centre; when the depth of the source is greater, the impact of thermocline on acoustic propagation is smaller; and the impact on high frequencies is greater than on low frequencies.