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  • Ocean Water Masses-Intermediate, Deep andBottom Waters

    C. Chen

    General Physical OceanographyMAR 555

    School for Marine Sciences and TechnologyUmass-Dartmouth

  • East Pacific Ocean East Atlantic Ocean

    2

    6

    107

    12

    13

    15

    203040

    1

    2

    3

    4

    5

    10

    2045

    1

    Surface or Upper Water(SW)

    Central Water(CW) IntermediateWater(IW)

    Deep or BottomWater(DW or BW)

    SW

    CW

    CIW

    IW

    DW

    CIW-California Intermediate Water: low salinity MIW-Mediterranean Intermediate Water: high salinity

    MAR 555 Lecture 11: Ocean Water Masses-Intermediate, Deep and Bottom Waters

  • Formation of Intermediate Waters

    1. Form in subpolar region where precipitation exceeds evaporation,so it is characterized by low-temperature and low-salinity

    2. Sinking of the relatively denser water at the surface in subpolarconvergence zone. Since the salinity of this water is relatively low,it only stays in the depth region below the central water and abovethe deep and bottom water

    60o 40o 20o 0o 20o 40o 60o 80oN S

    0

    1

    2

    3

    4

    5

    Dep

    th (k

    m)

    Antarctic Intermediate Water

    North

    Deep

    AtlanticWater

    Antarctic Bo

    ttom W

    ater

    Mediterranean

    Water

    35

    34.8

    34.6

    Subpolar Frontal Zone

    Subtropical Convergence Zone

  • Intermediate Water Masses

    Red Sea-Persian GulfIntermediate Water

    Indonesia Intermediate Water

    Antarctic Intermediate WaterAntarcticIntermediate Water

    W. Atl.SubarcticInt. Water

    Source

    Med

    iterra

    nean

    Wat

    er

    E. Atl. Subarctic Int.Water

    Arctic Intl. Water

    Antarctic Intermediate Water

    California Intermediate Water

    Pacific Subarctic Intermedia

    te

    Water

    Source

    Characteristics: low-salinity and low temperature

    Depth range: 550-1500 m (California Int. Water ~ 200 m)

  • Indonesian Intermediate Water(IIW)T: 3.5-5.5oCS: 34.6-34.7 PSU

    Red Sea-Persian GulfIntermediate Water (RSPGIW)T: 5.0-14.0oCS: 34.8-35.4 PSU

    Antarctic Intermediate Water(AAIW)T: 2.0-10.0oCS: 33.8-34.8 PSU

    Pacific Subarctic IntermediateWater (PSIW)T: 5.0-12.0oCS: 33.8-34.3 PSU

    California Intermediate Water(CIW)T: 10.0-12.0oCS: 33.9-34.4 PSU

    Eastern South PacificIntermediate Water (ESPIW)T: 10.0-12.0oCS: 34.0-34.4 PSU

    Antarctic Intermediate Water(CDW)T: 2.0-10oCS: 33.8-34.5 PSU

    Arctic Intermediate Water (AIW)T: -1.5-3.0oCS: 34.7-34.9 PSU

    East Atlantic SubarcticIntermediate Water (EASIW)T: 3.0-9.0oCS: 34.4-35.3 PSU

    West Atlantic SubarcticIntermediate Water (WASIW)T: 3.0-9.0oCS: 34.0-35.1 PSU

    Mediterranean Water (MW)T: 2.6-11.0oCS: 35.0-36.2 PSU

    Antarctic Intermediate Water(AAIW):T: 2.0-6.0oCS: 33.8-34.8 PSU

    Indian OceanPacific OceanAtlantic Ocean

  • Download from the web source

    The Distributions of Water Temperature and Salinity of the IntermediateWater in North Atlantic Ocean influenced by the Mediterranean output

  • 200

    200

    SpainGibraltar

    Moroco0 10 km

    6o00' 5o40' 5o20'

    36o10'

    35o50' Gibraltar St

    rait

    38.4

    38.238.037.5

    37.0

    38.44

    38.42

    0

    100

    200

    300

    400

    500

    600

    700

    Dep

    th (m

    )

    5 km

    13.0

    12.95

    12.9

    13.0513.113.113.5

    14.015.0

    16.0

    N S

    S T

    Gibraltar Strait

    22

    20

    18

    16

    14

    12

    Pot

    entia

    l tem

    pera

    ture

    (oC

    )

    25.0

    26.0

    27.0

    28.0

    29.0

    Salinity 35 36 37 38 39

    12.90

    12.9513

    13.05

    13.05

    13.05

    13.05

    14 1516

    0

    400

    200

    600

    800

    1000

    Dep

    th (m

    )

    10 20Distance (km)

    30 40

    38.44

    38.4438.4438.4038.35

    38.30

    38.30

    38.10

    38.00 37.50

    37.0

    10 20Distance (km)

    30 40

    ST

    W E

  • Circumpolar Deep Water(CDW)T: 0.1-2.0oCS: 34.62-34.73 PSU

    Antarctic Bottom Water(AABW)T: -0.9-1.7oCS: 34.64-34.72 PSU

    Circumpolar Deep Water(CDW)T: 0.1-2.0oCS: 34.62-34.73 PSU

    Antarctic Bottom Water(AABW)T: -0.9-1.7oCS: 34.64-34.72 PSU

    North Atlantic Deep Water(NADW)T: -1.5-4.0oCS: 34.8-35.0 PSU

    Antarctic Bottom Water(AABW)T: -0.9-1.7oCS: 34.64-34.72 PSU

    Arctic Bottom WaterIntermediate Water (ABW)T: -1.8-(-10.5oC)S: 34.88-34.94 PSU

    Indian OceanPacific OceanAtlantic Ocean

    Deep and Bottom Waters

  • North Atlantic Deep Water (NADW)

    Fram Strait

    Warm andhigh salinity

    Cool and sinkIn Norwegian and GreenlandSead

    Low temperaturehigh salinity

  • 1. North Atlantic Current (8oC and 35.25)

    Warm/

    saline

    Water accumulation (2.5oC and >35)

    2000-3000 m

    Gree

    nland

    Iceland Norw

    ay

    Formation of icecold, high salinity

    Convergence

    Convergence

    Convergence

    Cooling

    North Atlantic Deep Water

    The Norwegian SeaThe Greenland Sea

    2. Ice formation in the Arctic Ocean

    3. The Labrador Sea

  • Greenland

    Norw

    ay

    Iceland

    FramStrait

    NorwegianSea

    GreenlandSea

    NW Atlantic Deep Water

    NE Atlantic Deep Water

    Denm

    akr S

    trait

    DWBC

  • Cold High salinity water

    Latent heat

    Latent heat

    2000 m

    Winds from

    Antarctic

    continent

    Newly formed ice pushed away from coast

    Open Ocean Polynya Coastal Polynya

    cold, dense water

    Relatively

    warm

    water

    Formation of the Antarctic Bottom Water

    Polynya is a Russian word meaning an enclosed area of unfrozen watersurrounded by ice

  • Schematic of the physical process in a coastal polynya

    Side view

    Top view

    Front view

    From Seelye Martin (2007)

  • Open-ocean polynya mean circulation and mixing

    From Seelye Martin (2007)

  • From Seelye Martin (2007)

  • Weddell Polyna during 1973-1976

  • http://earth.esa.int/workshops/ers97/papers/drinkwater/

    Reappearance of the Weddell Polynya in scatterometer image August 1994. The orangeline indicates the cruise track of the Nathaniel Palmer during the Anzflux experiment.

  • http://arise-in-antarctica.blogspot.com/

    A view of the Terra Nova Polynya in thewestern Ross Sea

    Download from

  • http://polar.ncep.noaa.gov/seaice/Weddell.html

  • AABWsources

    AABWSources

    NADW

    NADW

    NADW Source region

    AABW

    Global distribution of NADW and AABW