September 25, 2011, 4:26 pm

A Sverdrup is a unit of transport applied to currents in oceanography and the water cycle. It measures the movement of one million cubic meters (106 m3) of water per second or 1x106 m3s−1.

The Sverdrup is abbreviated as Sv (not to be confused with the SI derived unit of dose equivalent, the sievert which also has the abbreviation Sv)

A Sverdrup is equal to 0.001 km3/s, or a current of 1,000 Sv is equal to a flow of 1 cubic kilometer per second (1 km3s-1)

The unit is named after the Norwegian oceanographer Harald Ulrik Sverdrup (1888–1957)

Lagerloef and colleagues note that:

Evaporation from the global ocean is estimated to be ~ 13 Sv, and the precipitation sums to ~ 12.2 Sv. The difference of 0.8 Sv compares with the estimate of river input of 1.2 Sv. The apparent imbalance of ~ 0.4 Sv excess is smaller than the estimated error bars. Sea level rise due to melting glaciers is only ~ 0.01 Sv, so cannot account for the imbalance. Global groundwater flows are poorly known but generally estimated to be similarly small (Cable et al., 1996). Likely sources of error include scant data in the southern oceans and a possible underestimate of evaporation in very-high-wind conditions. Other surface flux climatologies display similar patterns, but the range of the estimates is quite large and unlikely to be significantly improved in the near future.


  1. Lagerloef, G., Schmitt, R., Schanze, J. Kao, H-Y, 2010, The Ocean and the Global Water Cycle, Oceanography, Vol.23, No.4
  2. George Karleskint, Richard Turner, James Small. 2009. Introduction to Marine Biology. 581 pages




Baum, S. (2011). Sverdrup. Retrieved from http://www.eoearth.org/view/article/170400


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