Abstract
Tropical cyclones are important natural hazards and a key component of the Earth’s climate system. Changes in their distribution and frequency are important elements of the climate response to global warming. The Intergovernmental Panel on Climate Change states “with high confidence” that the proportion of intense tropical cyclones (categories 4-5) and peak wind speeds will increase globally. The same assessment concludes that it is “likely” that the global proportion of major tropical cyclones (categories 3-5) has increased over the last four decades and the latitudes where they reach their peak intensity is shifting northward.
The Comprehensive Nuclear Test Ban Treaty Organization operates a global International Monitoring System, with 11 hydroacoustic stations around the globe. In this study, we use data from Wake Island sensor H11N1, located in the deep ocean sound channel in the Pacific Ocean, placed to detect signals from around the Pacific. Continuous measurements provide data at frequencies up to 100 Hz over many years. We investigate a series of cyclones that occurred in 2010: Fanapi (14 – 21 September, Category 3), Malakas (20 – 25 September, Category 2), Megi (12 – 24 October, Category 5) and Chaba (20 October – 1 November, Category 5). Some are continuously in the oceanic line-of-sight from Wake Island, whereas others make landfall and/or continue over sea but not in the line-of-sight.
Using spectral analyses and multiscale aggregations of 1-minute PSD levels, we compare the respective underwater acoustic signatures of these cyclones over several days to assess the reliability of long-range cyclone detection using low frequencies only. The roles of different frequency bands and ranges to the monitoring station are investigated, along with changes to the underwater acoustic signatures as cyclones make landfall. This study demonstrates the potential of low frequencies to monitor cyclones and assess their contributions to the underwater environment.
The Comprehensive Nuclear Test Ban Treaty Organization operates a global International Monitoring System, with 11 hydroacoustic stations around the globe. In this study, we use data from Wake Island sensor H11N1, located in the deep ocean sound channel in the Pacific Ocean, placed to detect signals from around the Pacific. Continuous measurements provide data at frequencies up to 100 Hz over many years. We investigate a series of cyclones that occurred in 2010: Fanapi (14 – 21 September, Category 3), Malakas (20 – 25 September, Category 2), Megi (12 – 24 October, Category 5) and Chaba (20 October – 1 November, Category 5). Some are continuously in the oceanic line-of-sight from Wake Island, whereas others make landfall and/or continue over sea but not in the line-of-sight.
Using spectral analyses and multiscale aggregations of 1-minute PSD levels, we compare the respective underwater acoustic signatures of these cyclones over several days to assess the reliability of long-range cyclone detection using low frequencies only. The roles of different frequency bands and ranges to the monitoring station are investigated, along with changes to the underwater acoustic signatures as cyclones make landfall. This study demonstrates the potential of low frequencies to monitor cyclones and assess their contributions to the underwater environment.
Original language | English |
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Pages | 39 |
Publication status | Published - 19 Jun 2022 |
Event | International Conference on Underwater Acoustics ICUA-2022 - Southampton, UK United Kingdom Duration: 19 Jun 2022 → 23 Jun 2022 https://icua2022.org/ |
Conference
Conference | International Conference on Underwater Acoustics ICUA-2022 |
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Abbreviated title | ICUA-2022 |
Country/Territory | UK United Kingdom |
City | Southampton |
Period | 19/06/22 → 23/06/22 |
Internet address |
Keywords
- underwater acoustics
- Long-term monitoring
- climate change
- cyclones
- Typhoon
- Comprehensive Test Ban Treaty Organization
ASJC Scopus subject areas
- Acoustics and Ultrasonics