The gist

The Ocean Cleanup develops technologies to help rid the world’s oceans of plastic. The majority of ocean plastic is found within five oceanic gyres, with the largest one being the Great Pacific Garbage Patch (GPGP). Lead Computational Modeler Bruno Saint-Rose combines Sofar’s marine weather forecasts with Spotter buoy data to better understand metocean conditions and plastic drift patterns near the GPGP. This data increases the operational efficiency of the cleanup system.

The collaborators

• ‍The Ocean Cleanup is a nonprofit that develops and scales technologies to rid the ocean of plastic. To date, it has removed more than 1.78 million kg of trash from oceans and rivers around the world.
• Sofar Ocean is a San Francisco-based climate technology startup that is connecting the world’s oceans to power a more sustainable future. Science, society, and industry use its Spotter and Smart Mooring devices to collect real-time metocean data at and below the surface.

How the validation of forecasts and plastic drift tracks informs operational decisions

The GPGP is one of The Ocean Cleanup’s primary areas of operation. It is located halfway between California and Hawaii and is the largest accumulation of ocean plastic in the world, with an estimated surface area of 1.6 million square km. To clean the GPGP, two vessels operated by Maersk drag an 800m-long U-shaped barrier (lovingly named “Jenny”) through the debris field, capturing large quantities of surface plastic in a retention zone. Periodically, this plastic is extracted by boat and returned to shore for processing.

Bruno and his team use Sofar’s global wave forecast and historical and real-time Spotter data, accessed via the Sofar API, to create a more comprehensive picture of ocean dynamics in the North Pacific. By increasing understanding of weather and currents in the region, Bruno is better equipped to recommend when, where, and how the cleanup system should be deployed:

• Using Sofar’s Marine Weather and Spotter API endpoints, Bruno integrates recent (last 72 hours) and real-time ocean surface and weather observations from the North Pacific into his operational data science pipeline.
• These observations are used to validate The Ocean Cleanup’s weather models, as well as the performance of forecasts from ECMWF, NOAA, and others.
• If a forecast is consistent with the observations, it is given priority; prioritized forecasts inform key operational decisions, including what route the cleanup system takes through the GPGP.
• Bruno also accesses the historical GPS data for Spotters in the North Pacific. The drift track of each device serves as a proxy for the drift track of plastic, helping The Ocean Cleanup predict how and where plastic may accumulate in and around the GPGP. The data also expands The Ocean Cleanup’s understanding of plastic transport during small and large scale convergences.

Making go/no-go decisions using real-time ocean observations

The Ocean Cleanup uses a two meter threshold for wave height — amongst other variables — to determine whether or not it is safe to extract the plastic collected by the cleanup system in the retention zone onto a vessel. A transfer, which requires careful coordination with crane and short-range vessel operators, can only occur during a calm weather window. Occasionally, conflicting forecasts complicate the decision to greenlight a transfer; some predict wave heights above two meters, while others predict wave heights below two meters. The opportunity cost of following the wrong forecast is large; an extraction in inclement weather is dangerous, while a day of inactivity leaves thousands of kgs of plastic uncollected. Inefficient operations like these increase the cost per kg of plastic collected, a key performance indicator for The Ocean Cleanup. To avoid these situations, Bruno uses the Spotters’ in-situ wave height observations to help identify the most accurate forecast and inform a go/no go decision.

To read more Customer Stories, check out the Sofar Ocean Blog. Interested in learning more about use cases for Sofar’s ocean data? Schedule a Spotter smart buoy demo or Data Services demo with the Sofar team.