Scientists at the University of Michigan have developed an innovative way of using NASA satellite data to track the movement of tiny pieces of plastic in the ocean.
Microplastics are created when plastic waste in the ocean is broken down by the sun’s rays and the movement of ocean waves. These small plastic stains are harmful to marine organisms and ecosystems. Microplastics can be carried hundreds or thousands of kilometers from their source by ocean currents, making them difficult to track down and remove. Currently, the main source of information on the location of microplastics comes from fishing boat trawlers using nets to catch plankton – and inadvertently microplastics as well.
The new technology is based on data from NASA’s Cyclone Global Navigation Satellite System (CYGNSS), a constellation of eight small satellites that measure wind speeds over the Earth’s oceans and provide information about the strength of hurricanes. CYGNSS also uses radar to measure sea roughness, which is influenced by several factors, including wind speed and debris floating in the water.
In reverse, the team looked for places where the ocean was smoother than expected given the wind speed, which in their opinion could indicate the presence of microplastics. Then they compared these areas with observations and model predictions of where microplastics accumulate in the ocean. The scientists found that microplastics tend to be found in smoother waters, showing that CYGNSS data can be used as a tool to track microplastics from the ocean from space.
The results were published online on June 9, 2021 in online IEEE Transactions of Geoscience and Remote Sensing . The work was carried out by Chris Ruf, professor at the University of Michigan and lead researcher for CYGNSS, and undergraduate Madeline C. Evans.