2023_programme: Long-term effects of ocean temperature rise on the deep sea

• Session: 03. Comprehensive Nuclear-Test-Ban Treaty Monitoring and its Civil and Scientific Applications
  Organiser(s): Georgios Haralabus, Mario Zampolli and Peter Nielsen
• Lecture: Long-term effects of ocean temperature rise on the deep sea
  Paper ID: 1982
  Author(s): Audone Gianluca, Nunes Matt, Blondel Philippe, Budd Chris, Harris Peter, Robinson Stephen
  Presenter: Audone Gianluca
  Abstract: The Comprehensive Nuclear Test Ban Treaty Organization operates a global International Monitoring System, with 11 hydroacoustic stations around the globe located in the deep-sea sound channel. Continuous measurements provide up to 20 years of sound pressures at frequencies of up to 100 Hz, depending on when each station was installed. These relatively long timescales allow investigating the effects of climate over that period.\nThis presentation will show data from CTBT stations H11 (Wake Island, , in the North Pacific) and H01 (Cape Leeuwin, in the Indian Ocean). Multiscale aggregations of 1-minute power spectral density (PSD) levels and sound energy measures over several days are used to show their correlation with sea surface temperature (SST) measurements at different timescales. In particular, we can detect seasonal changes in the SST as well as longer term climatic variations. The spectral analysis also shows periodic features in PSD levels around 15 to 31 Hz. \nThe Intergovernmental Panel on Climate Change concluded in 2014 that the increase in temperature has mostly affected the upper (0 – 700 m) ocean while assessing the impact of climate change in the deep sea (> 1000 m) is a challenging task due to the difficulty of gathering long-term comprehensive data. This link between sound pressure levels at 1-km depths and the surface temperature of the ocean is particularly important. Sound is an Essential Ocean Variable, and a key factor to better understand the Earth’s climate system.
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• Corresponding author: Mr Gianluca Audone
  Affiliation: University Of Bath
  Country: United Kingdom
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