oceanography Oceanography (), also known as oceanology, sea science, ocean science, and marine science, is the scientific study of the ocean, including its physics, chemistry, biology, and geology. It is an Earth science, which covers a wide range of to ...

, the sverdrup (symbol: Sv) is a non- SI

metric unit The metric system is a system of measurement that standardizes a set of base units and a nomenclature for describing relatively large and small quantities via decimal-based multiplicative unit prefixes. Though the rules governing the metric ...

volumetric flow rate In physics and engineering, in particular fluid dynamics, the volumetric flow rate (also known as volume flow rate, or volume velocity) is the volume of fluid which passes per unit time; usually it is represented by the symbol (sometimes \do ...

, with equal to . It is equivalent to the SI derived unit cubic

hectometer The hectometre, ( SI symbol: hm), spelt hectometer in American and Philippine English, is a unit of length in the International System of Units (SI), equal to one hundred metres and to one tenth of a kilometre. The word comes from a combination ...

per second (symbol: hm³/s or hm³⋅s⁻¹): is equal to . It is used almost exclusively in

to measure the volumetric rate of transport of

ocean current An ocean current is a continuous, directed movement of seawater generated by a number of forces acting upon the water, including wind, the Coriolis effect, breaking waves, cabbeling, and temperature and salinity differences. Depth contours, sh ...

s. 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

s, a volume of one million cubic meters may be imagined as a "slice" of ocean with dimensions × × (width × length × thickness) or a cube with dimensions × × . 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 The metre per second is the unit of both speed (a scalar quantity) and velocity (a vector quantity, which has direction and magnitude) in the International System of Units (SI), equal to the speed of a body covering a distance of one metre in ...

). Thus, a hypothetical current wide, (m) deep, and moving at would be transporting of water. The sverdrup is distinct from the SI

sievert The sievert (symbol: SvPlease note there are two non-SI units that use the same Sv abbreviation: the sverdrup and svedberg.) is a derived unit in the International System of Units (SI) intended to represent the stochastic health risk of ionizin ...

unit or the non-SI

svedberg In chemistry, a Svedberg unit or svedberg (symbol S, sometimes Sv) is a non- SI metric unit for sedimentation coefficients. The Svedberg unit offers a measure of a particle's size indirectly based on its sedimentation rate under acceleration ...

unit. All three use the same symbol, but they are not related.

History

The sverdrup is named in honor of the Norwegian oceanographer, meteorologist and polar explorer Harald Ulrik Sverdrup (1888–1957), who wrote the 1942 volume ''The Oceans, Their Physics, Chemistry, and General Biology'' together with Martin W. Johnson and Richard H. Fleming. In the 1950s and early 1960s both Soviet and North American scientists contemplated the damming of the

Bering Strait The Bering Strait ( , ; ) is a strait between the Pacific and Arctic oceans, separating the Chukchi Peninsula of the Russian Far East from the Seward Peninsula of Alaska. The present Russia–United States maritime boundary is at 168° 58' ...

, thus enabling temperate Atlantic water to heat up the cold

Arctic Sea The Arctic Ocean is the smallest and shallowest of the world's five oceanic divisions. It spans an area of approximately and is the coldest of the world's oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, a ...

and, the theory went, making Siberia and northern Canada more habitable. As part of the North American team, Canadian oceanographer Maxwell Dunbar found it "very cumbersome" to repeatedly reference millions of cubic meters per second. He casually suggested that as a new unit of water flow, "the inflow through Bering Strait is one sverdrup". At the Arctic Basin Symposium in October 1962, the unit came into general usage.

Examples

The water transport in the

Gulf Stream The Gulf Stream is a warm and swift Atlantic ocean current that originates in the Gulf of Mexico and flows through the Straits of Florida and up the eastern coastline of the United States, then veers east near 36°N latitude (North Carolin ...

gradually increases from in the

Florida Current The Florida Current is a thermal ocean current that flows from the Straits of Florida around the Florida Peninsula and along the southeastern coast of the United States before joining the Gulf Stream Current near Cape Hatteras. Its contributing cu ...

to a maximum of south of Newfoundland at the

longitude Longitude (, ) is a geographic coordinate that specifies the east- west position of a point on the surface of the Earth, or another celestial body. It is an angular measurement, usually expressed in degrees and denoted by the Greek lett ...

55° W. The Antarctic Circumpolar Current, at approximately , is the largest ocean current. The entire global input of

fresh water Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salt (chemistry), salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include ...

from rivers to the ocean is approximately .

References

{{reflist Non-SI metric units Oceanography Units of flow