{"p": "dpi_PRESWAT_L1", "c": "dpi_CONDWAT_L1", "t": "dpi_TEMPWAT_L1"}
Salinity is generally defined as the concentration of dissolved salt in a parcel of seawater. Practical Salinity is a more specific unitless quantity calculated from the conductivity of seawater and adjusted for temperature and pressure. It is approximately equivalent to Absolute Salinity (the mass fraction of dissolved salt in seawater) but they are not interchangeable.