North Sea Sound Maps 2019-2020: Deliverable/Task: WP 4
de Jong, C.A.F.
de Krom, P.P.J.
The Joint Monitoring Programme for Ambient Noise in the North Sea project (Jomopans) has developed a framework for an operational joint monitoring programme for ambient noise in the North Sea. Statistical sound maps can be used by managers, planners and other stakeholders to incorporate the effects of ambient noise in their assessment of the environmental status of the North Sea, and to evaluate measures to improve the environment. The proposed framework applies numerical modelling for creating sound maps of the North Sea area, supported by local measurements for evaluation of the uncertainties in the numerical modelling. In 2021, Jomopans produced statistical sound maps for the sound of shipping and wind in the North Sea in the twelve months of the year 2019. One of the sources of uncertainty in these sound maps is the quality and completeness of the model input data that describes the ship traffic. Raw data from the Automatic Identification System (AIS) for ship traffic has to be postprocessed to obtain snapshots of the locations of all vessels at a regular time grid, together with information about the ship type, length and speed of each vessel. This postprocessing has been further studied in the Jomopans extension (July 2021 – June 2022). AIS data from two different providers have been compared for May 2019, to quantify the uncertainty in the sound maps due to uncertainty in the AIS data. Additional sound maps were then produced for the twelve months of 2020. In 2020 the Covid-19 pandemic affected ship traffic on the North Sea, but the change in the monthly (merchant) ship density appears to be small and variations in shipping noise smaller than the uncertainty in the sound maps. The Jomopans monitoring approach, based on large scale sound map modelling validated with local measurements, provides a relatively stable assessment of the pressure of shipping sound on the environment at the North Sea scale. Maps of monthly median sound pressure level and excess level of shipping noise over wind noise do not show significant variation over the months of 2019 and 2020. For local assessments at a smaller spatial or temporal scale, the uncertainty in the maps increases. Application of the monitoring approach at smaller scale would require high quality local input data (particularly of ship traffic and of local sediment properties) and local measurements to assess the contribution of other sources than shipping and wind to the soundscape
To reference this document use:
EU, Interreg North Sea Region JOMOPANS
Joint Monitoring Programme for Ambient Noise North Sea 2018 – 2022