Dear all,
We are pleased to invite you to the next WISE Webinar on the topic of Wave Dynamics taking place on 24/10/2024 at 17.00-18.00 Paris time.
Join us via https://tudelft.zoom.us/my/wisezoominars on 24th October 17.00-18.00 Paris time!
Speaker: Jim Thomson**, University of** Washington
Title: Wave development, bubbles, and ambient sound in the ocean
Abstract:
Wind, wave, and acoustic observations are used to test a new scaling for ambient sound levels in the ocean. The focus is on acoustic frequencies in the range 1-10 kHz, which are typical frequencies for “wind noise”. In contrast to existing models that are purely based on wind speed, the new scaling includes wave development as an additional factor. Wind and wave information are combined in a parametric form to describe the depth of the active bubble layer (which produces sound) relative to the depth of the passive bubble layer (which attenuates sound). This relative depth scaling is a plausible explanation for the observed reduction in sound levels during high wind events (winds > 15 m/s) and depends on how far the waves are from a fully-developed condition. The relative bubble depth scaling is tested with long time-series observations of winds and waves at Ocean Station Papa (North Pacific Ocean), as well as with a case study with fetch limitation near the island of Jan Mayen (Norwegian Sea). When waves are less developed (e.g., limited by fetch) at a given wind speed, the attenuating layer is relatively thin and the sound levels are higher. This work may improve prediction of ambient sound levels in the ocean, and it is an example of wave dependence in the larger climate system.
Please note that WISE Webinars including the Q&A will be recorded and posted on the WISE YouTube Channel afterwards (https://www.youtube.com/@wisezoominars). By participating, you consent to any information you share to be included in the recording and shared.
Best wishes,
Tripp, Alvise, Morteza, Ton, Qingxiang and Bernard.
(The WISE Webinar organizing committee)