20
Chemical Oceanography, 4th Edition
Central America. Part goes north and part goes south. The southern component is called
the Brazil Current. This current turns east at the subtropical convergence and becomes
part of the Circumpolar Current. It turns north off the coast of Africa and becomes the
Benguela Current. The Brazil Current is warm and salty water, while the Circumpolar
Current is cold and less saline. The Falkland Current flows north from the Drake Passage
up the coast of South America. It separates the Brazil Current from the coast to about 25° S.
One of the most studied currents in the Atlantic is the Gulf Stream. Studies have been
made on the formation of Gulf Stream rings. These rings are formed from the meandering
of the Gulf Stream (see Figure 1.26). Two types of rings are formed: cold core rings and
warm core rings. The cold core rings are formed from the waters north of the Gulf Stream.
This colder slope water forms a counterclockwise gyre that moves to the south. These
rings (The Ring Group, 1981) can exist for 2 to 4 yr but usually rejoin the Gulf Stream
after 6 to 12 months. The warm core rings are formed from the closure of a ring of warm
Sargasso Sea water. This clockwise gyre of warm water moves toward the north.
The cold core rings are rich in nutrients and support increased productivity in these
waters. The temperature structure of a typical ring is shown in Figure 1.27. The cold,
nutrient- rich waters are brought toward the surface as a result of the circulation. This
increase in nutrients results in the productivity of plankton in the rings. By using satellite images (Figure 1.28), it is possible to study the formation and destruction of rings by
Nor. C.
Eu ro pe
N. Atl. C.
North
Amer.
Gulf Stream
Fl. C.
Canary C.
N. Eq. C.
Eq. C. C.
S. Eq. C.
Africa
Benguela C.
Brazil C.
South
America
Peru
C.
Falkland C.
Circumpolar C.
Antilles C.
L a b . C .
Figure 1.25
The surface currents of the Atlantic Ocean.
Chemical Oceanography, 4th Edition
Central America. Part goes north and part goes south. The southern component is called
the Brazil Current. This current turns east at the subtropical convergence and becomes
part of the Circumpolar Current. It turns north off the coast of Africa and becomes the
Benguela Current. The Brazil Current is warm and salty water, while the Circumpolar
Current is cold and less saline. The Falkland Current flows north from the Drake Passage
up the coast of South America. It separates the Brazil Current from the coast to about 25° S.
One of the most studied currents in the Atlantic is the Gulf Stream. Studies have been
made on the formation of Gulf Stream rings. These rings are formed from the meandering
of the Gulf Stream (see Figure 1.26). Two types of rings are formed: cold core rings and
warm core rings. The cold core rings are formed from the waters north of the Gulf Stream.
This colder slope water forms a counterclockwise gyre that moves to the south. These
rings (The Ring Group, 1981) can exist for 2 to 4 yr but usually rejoin the Gulf Stream
after 6 to 12 months. The warm core rings are formed from the closure of a ring of warm
Sargasso Sea water. This clockwise gyre of warm water moves toward the north.
The cold core rings are rich in nutrients and support increased productivity in these
waters. The temperature structure of a typical ring is shown in Figure 1.27. The cold,
nutrient- rich waters are brought toward the surface as a result of the circulation. This
increase in nutrients results in the productivity of plankton in the rings. By using satellite images (Figure 1.28), it is possible to study the formation and destruction of rings by
Nor. C.
Eu ro pe
N. Atl. C.
North
Amer.
Gulf Stream
Fl. C.
Canary C.
N. Eq. C.
Eq. C. C.
S. Eq. C.
Africa
Benguela C.
Brazil C.
South
America
Peru
C.
Falkland C.
Circumpolar C.
Antilles C.
L a b . C .
Figure 1.25
The surface currents of the Atlantic Ocean.