Table 2.1 Natural regions of the oceans
a
Dietrich group and types
Ecoregion equivalents
B Boreal regions
Polar domain (500)
Inner boreal (Bi)
Inner polar division (510)
Outer boreal (Ba¨)
Outer Polar division (520)
W Westerly drift ocean regions
Temperate domain (600)
Poleward of oceanic polar front (Wp)
Poleward westerlies division (610)
Equatorward of polar front (Wa¨)
Equatorward westerlies division (620)
R Horse latitude ocean regions
Subtropical division (630)
High salinity subtropical division (640)
b
F Jet current regions
Jet stream division (650)
M Monsoon ocean regions
Poleward monsoons (Mp)
Poleward monsoon division (660)
Tropical domain (700)
Tropical monsoon (Mt)
Tropical monsoon division (710)
High salinity tropical monsoon division (720)
b
P Trade wind regions
With poleward current (Pp)
Poleward trades division (730)
With westerly current (Pw)
Trade winds division (740)
With equatorward component (Pa¨)
Equatorward trades division (750)
A Equatorial ocean regions
Equatorial countercurrent division (760)
a
From the Dietrich system (1963)
b
Not recognized by Dietrich; from Elliott (1954)
Table 2.2 Definitions and boundaries of the Dietrich system
P
(Passat in German), persistent westerly setting currents
Pa¨
With 30
equatorward component
Pw Predominantly westerly set
Pp
With 30
poleward current
A
(Aquator in German), regions of currents directed, at times or all year to the east
M
(Monsun in German), regions of regular current reversal in spring and autumn
Mt
Low-latitude monsoon areas of little temperature variation
Mp Mid to high (poleward) latitude equivalents of large temperature variations
R
(Ross in German), at times or all year marked by weak or variable currents
F
(Freistrahlregionen in German), all-year, geostropically controlled narrow current belts of mid-latitude
westerly margins of oceans
W
(Westwind in German), marked by somewhat variable but dominantly east-setting currents all year
Wa¨ Equatorward of oceanic polar front (convergence)
Wp Poleward of oceanic polar front (convergence)
B
At times or throughout the year, ice covered, in Arctic and Antarctic seas
Bi
Entire year covered with ice
Ba¨
Winter and spring covered with ice
14
2 Oceanic Types and Their Controls
a
Dietrich group and types
Ecoregion equivalents
B Boreal regions
Polar domain (500)
Inner boreal (Bi)
Inner polar division (510)
Outer boreal (Ba¨)
Outer Polar division (520)
W Westerly drift ocean regions
Temperate domain (600)
Poleward of oceanic polar front (Wp)
Poleward westerlies division (610)
Equatorward of polar front (Wa¨)
Equatorward westerlies division (620)
R Horse latitude ocean regions
Subtropical division (630)
High salinity subtropical division (640)
b
F Jet current regions
Jet stream division (650)
M Monsoon ocean regions
Poleward monsoons (Mp)
Poleward monsoon division (660)
Tropical domain (700)
Tropical monsoon (Mt)
Tropical monsoon division (710)
High salinity tropical monsoon division (720)
b
P Trade wind regions
With poleward current (Pp)
Poleward trades division (730)
With westerly current (Pw)
Trade winds division (740)
With equatorward component (Pa¨)
Equatorward trades division (750)
A Equatorial ocean regions
Equatorial countercurrent division (760)
a
From the Dietrich system (1963)
b
Not recognized by Dietrich; from Elliott (1954)
Table 2.2 Definitions and boundaries of the Dietrich system
P
(Passat in German), persistent westerly setting currents
Pa¨
With 30
equatorward component
Pw Predominantly westerly set
Pp
With 30
poleward current
A
(Aquator in German), regions of currents directed, at times or all year to the east
M
(Monsun in German), regions of regular current reversal in spring and autumn
Mt
Low-latitude monsoon areas of little temperature variation
Mp Mid to high (poleward) latitude equivalents of large temperature variations
R
(Ross in German), at times or all year marked by weak or variable currents
F
(Freistrahlregionen in German), all-year, geostropically controlled narrow current belts of mid-latitude
westerly margins of oceans
W
(Westwind in German), marked by somewhat variable but dominantly east-setting currents all year
Wa¨ Equatorward of oceanic polar front (convergence)
Wp Poleward of oceanic polar front (convergence)
B
At times or throughout the year, ice covered, in Arctic and Antarctic seas
Bi
Entire year covered with ice
Ba¨
Winter and spring covered with ice
14
2 Oceanic Types and Their Controls