Sverdrup

In oceanography, the sverdrup (symbol: Sv) is a non-SI metric unit of volumetric flow rate, with 1 Sv equal to 1 million cubic meters per second (35314667 cu ft/s), or equivalently 1 cubic hectometer per second (symbol: hm3/s or hm3⋅s−1). It is used almost exclusively in oceanography to measure the volumetric rate of transport of ocean currents. It is named after Harald Sverdrup. One sverdrup is about five times what is carried at the estuary by the world's largest river, the Amazon. In the context of ocean currents, a volume of one million cubic meters may be imagined as a "slice" of ocean with dimensions 1 km × 1 km × 1 m (width × length × thickness) or a cube with dimensions 100 m × 100 m × 100 m. At this scale, these units can be more easily compared in terms of width of the current (several km), depth (hundreds of meters), and current speed (as meters per second). Thus, a hypothetical current 50 km wide, 500 m (0.5 km) deep, and moving at 2 m/s would be transporting 50 Sv of water. The sverdrup is distinct from the sievert, SI unit of radiation, or the svedberg, non-SI unit of sedimentation rate. All three use the same symbol, but they are not related.