2025_programme: Deep-ocean soundscapes: The impact of atmospheric carbon dioxide

• Day: June 16, Monday
    Location / Time: A. TERPSIHORI at 12:40-13:00
• Last minutes changes: -
• Session: 04. Comprehensive Nuclear-Test-Ban Treaty Monitoring, and its Civil and Scientific Applications
  Organiser(s): Georgios Haralabus, Mario Zampolli, Tiago Oliveira, Mark Prior
  Chairperson(s): Georgios Haralabus, Tiago Oliveira
• Lecture: Deep-ocean soundscapes: The impact of atmospheric carbon dioxide [Invited]
  Paper ID: 2316
  Author(s): Gianluca Audone, Philippe Blondel, Matthew Nunes, Chris Budd OBE
  Presenter: Gianluca Audone
  Abstract: The Comprehensive Nuclear Test Ban Treaty Organization manages a global International Monitoring System featuring 11 hydroacoustic stations installed in the deep-sea sound channel. Depending on when each station was commissioned, continuous measurements have accumulated up to 20 years of sound pressure data at frequencies reaching 100 Hz. These extended datasets provide a valuable foundation for exploring the long-term impacts of climate variability. This study uses data from CTBT stations Cape Leeuwin in the Indian Ocean and Wake Island in the Pacific Ocean, to investigate the impact of climate change on deep-ocean soundscapes. We analyse long-term acoustic data alongside atmospheric carbon dioxide (CO2) concentration trends to understand their relationship. Continuous measurements from these stations provide a unique opportunity to assess climatic effects over extended periods.\nMultiscale analysis of Sound Pressure Level (SPL) and Hjorth's Mobility is used to correlate acoustic parameters with CO2 concentrations. This approach allows us to detect seasonal changes and long-term climatic variations. Our findings reveal strong negative correlations between CO2 trends and both SPL and Hjorth's Mobility at Cape Leeuwin and Wake Island.\nThe Intergovernmental Panel on Climate Change (IPCC) has highlighted the difficulty of gathering comprehensive long-term data to assess the impact of climate change in the deep sea (>1000 m). This research addresses this challenge by linking sound pressure levels at depth with atmospheric CO2 concentrations. The observed relationships suggest that increasing CO2 concentrations may be associated with decreasing sound levels and alterations in the frequency content of the underwater soundscape. Sound is an Essential Ocean Variable, and this study emphasises the importance of understanding the Earth’s climate system through deep-ocean acoustics.
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  This paper is a candidate for the "Prof. John Papadakis award for the best paper presented by a young acoustician(under 40)"
• Corresponding author: Dr Gianluca Audone
  Affiliation: Politecnico di Torino
  Country: Italy