Ocean Water Masses-Intermediate, Deep and Bottom Waters

Home , Antarctic Bottom Water, Bottom water

C. Chen

General Physical Oceanography MAR 555

School for Marine Sciences and Technology Umass-Dartmouth MAR 555 Lecture 11: Ocean Water Masses-Intermediate, Deep and Bottom Waters

East Pacific Ocean East Atlantic Ocean

SW Surface or 1 Upper Water (SW) 1 2 CW Central Water

6 (CW) 7 2 CIW 10 Intermediate 3 12 Water 4 (IW) IW 13 5

20 Deep or Bottom 10 30 Water DW 40 20 (DW or BW) 45

CIW-California Intermediate Water: low salinity MIW-Mediterranean Intermediate Water: high salinity 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 subpolar convergence zone. Since the salinity of this water is relatively low, it only stays in the depth region below the central water and above the deep and bottom water

Subtropical Subpolar Convergence Zone Frontal Zone 0 Mediterranean Antarctic ter 1 Water Intermediate Wa ) 34.6 m r k 2 N 35 e ( t

o rt a h h W t A 34.8 p m tlan tto e 3 t o ic ic B D rct Deep Anta 4 Water

5 60o 40o 20o 0o 20o 40o 60o 80o N S Intermediate Water Masses

Arctic Intl. Water E. Atl. Subarctic Int. Water

n a e n a r r W. Atl. e t i r d e diate Subarctic t terme e rctic In a Suba M Pacific Int. Water W Water California Intermediate Water

Red Sea-Persian Gulf Intermediate Water

Indonesia Intermediate

Water

Antarctic Intermediate Water Antarctic Intermediate Water Antarctic Intermediate Water

Source Source

Characteristics: low-salinity and low temperature Depth range: 550-1500 m (California Int. Water ~ 200 m) Atlantic Ocean Pacific Ocean Indian Ocean

Arctic Intermediate Water (AIW) Pacific Subarctic Intermediate Indonesian Intermediate Water T: -1.5-3.0oC Water (PSIW) (IIW) S: 34.7-34.9 PSU T: 5.0-12.0oC T: 3.5-5.5oC S: 33.8-34.3 PSU S: 34.6-34.7 PSU East Atlantic Subarctic Intermediate Water (EASIW) California Intermediate Water Red Sea-Persian Gulf T: 3.0-9.0oC (CIW) Intermediate Water (RSPGIW) S: 34.4-35.3 PSU T: 10.0-12.0oC T: 5.0-14.0oC S: 33.9-34.4 PSU S: 34.8-35.4 PSU West Atlantic Subarctic Intermediate Water (WASIW) Eastern South Pacific Antarctic Intermediate Water T: 3.0-9.0oC Intermediate Water (ESPIW) (AAIW) S: 34.0-35.1 PSU T: 10.0-12.0oC T: 2.0-10.0oC S: 34.0-34.4 PSU S: 33.8-34.8 PSU Mediterranean Water (MW) T: 2.6-11.0oC Antarctic Intermediate Water S: 35.0-36.2 PSU (CDW) T: 2.0-10oC Antarctic Intermediate Water S: 33.8-34.5 PSU (AAIW): T: 2.0-6.0oC S: 33.8-34.8 PSU The Distributions of Water Temperature and Salinity of the Intermediate Water in North Atlantic Ocean influenced by the Mediterranean output

Download from the web source N S 0 Gibraltar Strait 7.0 16.0 3 15.0 100 37.5 38.0 14.0 38.2 13.5 13.1 36o10' Spain 13.1 Gibraltar 13.05 200 38.4 13.0 ) m ( 300 h 38.42 200 t

p 12.95 e 400

D 38.44 Strait 12.9 35o50' Gibraltar 500 200 Moroco 5 km 0 10 km 600 S T 6o00' 5o40' 5o20' 700

W E 0 22 16 37 15 .0 14 38.0 13 3 0 37. ) 0 0 .05 8.30 50 . . 3 C 5 6 13.05 8.3 o 2 2 200 5 0 20 13.05 3.0 38.10 1 .0 13 7 1 38.35 2 2. 95 0 1 38.4 400 2 38.44 18 . 8.44 9 3 0 44 8. 3 0 Depth (m) . 8 2 600 16

800 14 .0

Potential temperature ( 9 T S 2 1000 12 10 20 30 40 10 20 30 40 35 36 37 38 39 Distance (km) Distance (km) Salinity Deep and Bottom Waters

Atlantic Ocean Pacific Ocean Indian Ocean

North Atlantic Deep Water Circumpolar Deep Water Circumpolar Deep Water (NADW) (CDW) (CDW) T: -1.5-4.0oC T: 0.1-2.0oC T: 0.1-2.0oC S: 34.8-35.0 PSU S: 34.62-34.73 PSU S: 34.62-34.73 PSU

Antarctic Bottom Water (AABW) Antarctic Bottom Water Antarctic Bottom Water T: -0.9-1.7oC (AABW) (AABW) S: 34.64-34.72 PSU T: -0.9-1.7oC T: -0.9-1.7oC S: 34.64-34.72 PSU S: 34.64-34.72 PSU Arctic Bottom Water Intermediate Water (ABW) T: -1.8-(-10.5oC) S: 34.88-34.94 PSU North Atlantic Deep Water (NADW)

Fram Strait Low temperature high salinity

Cool and sink In Norwegian and Greenland Sead

Warm and high salinity Formation of ice cold, high salinity

Greenland Iceland Cooling Norway 1. North Atlantic Current e o in (8 C and 35.25) al /s m ar W C

C The Norwegian Sea o o C n n v o The Greenland Sea v e n e r v g r e g e r e n g

n 2. Ice formation in the c e c e n e

c Arctic Ocean e

Water accumulation 3. The Labrador Sea (2.5oC and >35) 2000-3000 m

North Atlantic Deep Water Fram

Strait Greenland

Greenland

Sea Norway

Norwegian Sea

DenmakrIceland Strait NE Atlantic Deep Water Deep Atlantic NE

NW Atlantic Deep Water

DWBC Formation of the Antarctic Bottom Water

Open Ocean Polynya Coastal Polynya

Winds from Antarctic continent

Latent heat

Newly formed ice pushed away from coast Latent heat c o w R l d a e , r l

a m d t e i

v w n e

2000 m s a l e y t e

w r a t e r Cold High salinity water

“Polynya” is a Russian word meaning “an enclosed area of unfrozen water surrounded 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 orange line indicates the cruise track of the Nathaniel Palmer during the Anzflux experiment. A view of the Terra Nova Polynya in the western Ross Sea Download from http://arise-in-antarctica.blogspot.com/ http://polar.ncep.noaa.gov/seaice/Weddell.html Global distribution of NADW and AABW

NADW Source region

NADW

AABW

NADW

AABW AABW sources Sources