Source Water Masses to be used for mixing studies



If one starts to use OMP analysis the first and fundamental problem that arises is the definition of the water masses for the mixing model. A rather incomplete collection of water masses is given here, separated into ocean basins, which will help to find the water involved in your studies.

The procedure for defining source water masses depends on the nature of the problem. You have to keep in mind that the solution procedure of OMP analysis will find a result even if you use definitions from a different ocean. Please inspect the residuals carefully to find shortcomings in your water mass definitions.

An important point to remember is that you should define source water masses in terms of physical processes (see Tomczak, 1999, for further information). Heuristic assumptions, such as plotting all data and finding vertices or endpoints of mixing lines, can sometimes be used if they can be justified in terms of physcal processes. In general, the vertex strategy has only merit in local studies.

Using local end members, the interpretation of biogeochemical cycling parameters such as the "age" in the extended OMP analysis is only possible in terms of ratios (eg. Hupe and Karstensen, 2000 ). Absolute cycling parameters (total change in oxygen or carbon) cannot be deduced as well, as one has to be careful in applying the fractions to reconstruct the undiluted content of anthropogenic tracers. For those studies a "preformed" definition of the source waters in their physical formation region is strongly recommended. If this is not done a preformed correction is necessary, and this again has to be made in relation to the ventilation sites (eg. the winter outcrop for the Central Waters), which implies the use of "real" ventilating water masses.

Please contribute your water mass definition values to our collection to improve further studies and to make the application of OMP analysis easier for "novices". If you SUBMIT your definition: Please send data in appropriate units (see above). At least for local definitions provide a map - the ocean is quite large!!

The following tables are separated into preformed and local definitions.




Note: For parameter definitions we used the abbreviations as given in the OMP manual.
The parameter units are: ptemp [°C], sal [psu], oxy [Ámol/kg], ph [Ámol/kg], ni [Ámol/kg], si [Ámol/kg]



Atlantic Ocean


Preformed Definitions

water mass name/submitted by characteristic usage (local, preformed, map??) author/year remarks (eg. definition method)
North Atlantic Central Water (NACW)
matthias.tomczak@flinders.edu.au
ptemp =   6.9973 -  13.9022
sal   =  34.9424 -  35.8986
oxy   = 291.6402 - 252.1236
ph    =   0.4640 -   0.1922
ni    =   5.8223 -   0.0869
si    =   3.8627 -   1.7944
preformed, based on World Ocean Atlas 1994 Poole and Tomczak (1999) derived from surface mixed layer data in formation region
Western South Atlantic Central Water (WSACW)
matthias.tomczak@flinders.edu.au
ptemp =   6.5519 -  16.2664
sal   =  34.4017 -  35.6921
oxy   = 295.4140 - 239.5682
ph    =   1.1156 -   0.2014
ni    =  13.3263 -   0.0
si    =   4.1156 -   1.6779
preformed, based on World Ocean Atlas 1994 Poole and Tomczak (1999) derived from surface mixed layer data in formation region
South Atlantic Central Water (SACW)
jkarstensen@ifm.uni-kiel.de
ptemp =  25 - 5 - 3
sal   =  37.1 - 34.1 - 34.1 
oxy   =  205 - 305 - 180
ph    =  0.25 - 1.05 - 2.1
ni    =  0 - 19 - 35
si    =  1.5 - 7.3 - 75
preformed, based on World Ocean Atlas 1994
Here is a map and a TS diagramm
Karstensen and Quadfasel (2000, submitted) derived from dynamic of the mixed layer and winter data along mixed layer surface

Local Definitions

water mass name/submitted by characteristic usage (local, preformed, map??) author/year remarks (eg. definition method)
Eastern South Atlantic Central Water (ESACW)
matthias.tomczak@flinders.edu.au< /A>
ptemp =   5.9559 -  14.4067
sal   =  34.4069 -  35.3016
oxy   = 300.0553 - 249.3363
ph    =   1.3083 -   0.2360
ni    =  11.7672 -   0.0
si    =   7.0952 -   3.6276
treated as a water mass imported from the Indian Ocean by the Agulhas Current, based on World Ocean Atlas 1994 Poole and Tomczak (1999) derived from vertical profile data south of Africa
Western North Atlantic Central Water (WNACW)
matthias.tomczak@flinders.edu.au< /A>
ptemp =   7.00 -  19.00
sal   =  35.00 -  36.65
oxy   =  165.4 -  235.3
ph    =   1.30 -   0.15
ni    =  20.00 -   2.00
si    =  15.00 -   2.00
temperature and salinity from Emery and Meincke (1986), nutrients from GEOSECS (Bainbridge, 1976) Hinrichsen and Tomczak (1999) derived from source regions; close to preformed?
Antarctic Intermediate Water (AAIW)
matthias.tomczak@flinders.edu.au< /A>
ptemp =   3.5
sal   =  34.55
oxy   =  165.2
ph    =   2.3
ni    =  33.0
si    =  45.0
data from GEOSECS (Bainbridge, 1976) Hinrichsen and Tomczak (1999) derived from data at depth in the southern hemisphere
North Atlantic Deep Water (NADW)
matthias.tomczak@flinders.edu.au< /A>
ptemp =   3.5
sal   =  34.945
oxy   =  271.8
ph    =   1.1
ni    =  17.6
si    =  11.0
own data from the study region Hinrichsen and Tomczak (1999) Hinrichsen and Tomczak (1999) data from the north western part of the study region
Western Atlantic Subarctic Intermediate Water (WASIW)
matthias.tomczak@flinders.edu.au< /A>
ptemp =   3.7
sal   =  34.8
oxy   = 271.8
ph    =   1.1
ni    =  17.0
si    =  10.0
own data from the study region Hinrichsen and Tomczak (1999) Hinrichsen and Tomczak (1999) data from the north western part of the study region
Labrador Current Water (LCW)
matthias.tomczak@flinders.edu.au< /A>
ptemp =  -0.28
sal   =  33.33
oxy   =  358.76
ph    =   0.6
ni    =   4.7
si    =   4.3
own data from the study region Hinrichsen and Tomczak (1999) Hinrichsen and Tomczak (1999) data from the north western part of the study region
Mediterranean Water (MW)
matthias.tomczak@flinders.edu.au< /A>
ptemp =  13.2
sal   =  37.72
oxy   =   200.0
ph    =   0.65
ni    =   9.1
si    =   6.5
station data from Rhein and Hinrichsen (1999) Hinrichsen and Tomczak (1999) data from the outflow region in the Gulf of Cadiz




Indian Ocean


Preformed Definitions

water mass name/submitted by characteristic usage (local, preformed, map??) author/year remarks (eg. definition method)
Indian Central Water (ICW)
jkarstensen@ifm.uni-kiel.de
ptemp =  20 - 13 - 9
sal   =  36.0 - 35.25 - 34.65 
oxy   =  227 - 244 - 268
ph    =  0.1 - 0.35 - 0.85
ni    =  0 - 1 - 7
si    =  2.5 - 2.5 - 2.5
preformed, based on World Ocean Atlas 1994
Here is a map and a TS diagramm
Karstensen and Quadfasel (2000, submitted) derived from dynamic of the mixed layer and winter data along mixed layer surface, biogeochemical cycling information deduceable
Austral Asian Intermediate Water (AAMW)
jkarstensen@ifm.uni-kiel.de
ptemp =  20  - 13    -  .4
sal   = 34.65 - 34.65 -  34.55
oxy   = 91    - 91    - 1 00
ph    =  2.1  -  2.1  -  1.4
ni    = 30    - 30    -  19
si    = 40    - 48    -  25
Inflow from the Indonesian Seas into the Indian Ocean
Here is a station map
Karstensen (1999) vertex from property/property plots in the Timor Sea (inflow region), biogeochemical cycling information NOT deduceable

Local Definitions

water mass name/submitted by characteristic usage (local, preformed, map??) author/year remarks (eg. definition method)
Antarctic Intermediate Water (AAIW)
jkarstensen@ifm.uni-kiel.de
ptemp =   4.5
sal   =  34.35
oxy   = 210
ph    =   2.2
ni    =  32
si    =  35
local, valid north of 30čS Karstensen (1999) statistical analysis of WOCE line I5 data




Pacific Ocean


Preformed Definitions

water mass name/submitted by characteristic usage (local, preformed, map??) author/year remarks (eg. definition method)
South Pacific Central Water (N-SPCW)
Eastern Outcrop (see map)
jkarstensen@ifm.uni-kiel.de
ptemp =  22 - 17 - 12
sal   =  36.07 - 34.84 - 34.0 
oxy   =  218 - 236 - 260
ph    =  0.7 - 0.3 - 0.6
ni    =  0 - 0.3 - 10.3
si    =  1.1 - 0.4 - 4.4
preformed, based on World Ocean Atlas 1994
Here is a map of the outcrop regions and a TS diagramm
Karstensen and Quadfasel (2000, submitted) derived from dynamic of the mixed layer and winter data along mixed layer surface
South Pacific Central Water (S-SPCW)
Western outcrop
jkarstensen@ifm.uni-kiel.de
ptemp =  19.4 - 5.8 - 2.5
sal   =  35.66 - 34.28 - 34.17 
oxy   =  210 - 280 - 178
ph    =  0.3 - 1.5 - 2.4
ni    =  1.3 - 20.7 - 34.2
si    =  1.1 - 6.4 - 49.4
preformed, based on World Ocean Atlas 1994
Here is a map of the outcrop and a TS diagramm
Karstensen and Quadfasel (2000, submitted) derived from dynamic of the mixed layer and winter data along mixed layer surface

Local Definitions

water mass name/submitted by characteristic usage (local, preformed, map??) author/year remarks (eg. definition method)

ptemp =
sal =
oxy =
ph =
ni =
si =




Southern Ocean

water mass name/submitted by characteristic usage (local, preformed, map??) author/year remarks (eg. definition method)
ptemp =
sal =
oxy =
ph =
ni =
si =




Arctic Ocean/GIN Sea

water mass name/submitted by characteristic usage (local, preformed, map??) author/year remarks (eg. definition method)
ptemp =
sal =
oxy =
ph =
ni =
si =




References:

A. E. Bainbridge GEOSECS Atlantic Expedition, vol. 2, Sections and Profiles.
National Science Foundation, Washington D.C., 1976.

W. J. Emery and J. Meincke Global water masses: summary and review.
Oceanol. Acta, 9, 383-391, 1986.

H.-H. Hinrichsen and M. Tomczak Optimum multiparameter analysis of the water mass structure in the western North Atlantic Ocean.
J. Geophys. Res., 98, 10,155-10,169, 1993.

A. Hupe and J. Karstensen Redfield stoichiometry in Arabian Sea subsurface waters.
Global Biogeochemical Cyles, 14(1), 357-372,2000.

J. Karstensen and D. Quadfasel Southern hemisphere thermocline waters
to be submitted to JGR.

J. Karstensen Über die Ventilation der Thermokline im Indischen Ozeans. (Online version)
Ph.D. thesis, Fachbereich Geowissenschaften, UniversitätHamburg, Germany, 1999

R. Poole and M. Tomczak Optimum multipararemeter analysis of the water mass structure in the Atlantic Ocean thermocline.
Deep-Sea Res., 46, 1895-1921, 1999.

M. Rhein and H.-H. Hinrichsen Modification of Mediterranean Water in the Gulf of Cadiz.
Deep-Sea Res., 40, 267-291, 1993.

M. Tomczak Some historical, theoretical and applied aspects of quantitative water mass analysis.
J. Mar. Res., 57, 275-303, 1999.


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