The researchers studied the movement of the Tagus Estuary plume in January 2007 caused by wind and river flow. They used a computer model to simulate how the plume spread along the Portuguese coast. The model accurately predicted the salinity and water temperature near Costa do Estoril. The plume near the Tagus mouth was influenced by the coastline, moving close to shore. When northern winds blew, the plume shifted offshore, but when the winds calmed, the plume moved back towards the coast, carrying estuarine water north along the Estremadura coast.