The study looked at how satellite images can help us understand estuaries by measuring how much light they reflect. They found that the amount and location of this reflected light are influenced by how much freshwater is flowing into the estuary and the tides. Estuaries with a mix of saltwater and freshwater are affected more by river flow, while those with more mixing are influenced by tides. By studying these reflections, we can learn more about what's happening below the surface in estuaries, like how much freshwater is entering and how the tides are affecting them. This information could help us monitor river flow and classify different types of estuaries.