This dataset contains in situ measurements from Conductivity Temperature Depth (CTD) casts and tows. It provides salinity, density, temperature and sound velocity of the water column. The CTDs were deployed from a ship either as single profile casts or towed yo-yo behind the ship to measure the physical properties of the water. This provided measurements of the ocean's physical characteristics around Greenland. The CTDs are part of the Oceans Melting Greenland (OMG) project. The goal of the project is to find out what contributions the ocean has on Greenland's melting glaciers.