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Salinity and turbidity

Started by Karin, June 06, 2010, 08:44:23 PM

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We are using SLAMM for a research project in south east Australia, and have two questions relating to the accretion model in v6.0.1:

(1) Turbidity Maximum Zone: It says a range of salinity should be specified - should this really be e.g. a lower limit above which there is some salinity effect (e.g. 15 ppt), or should it be given as a range (e.g. 15-35 ppt)?

(2) "S" Non Turbidity Maximum (unitless): In the description it says "Accretion limitation factor in region where there is no salinity effect". My colleagues and I have a hard time understanding what this really means? Is it always 0 or 1 or can it have any value?

Thanks a lot in advance,


Jonathan S. Clough

(1) Unless you are running the optional salinity sub-model you shouldn't specify a turbidity maximum zone feedback as part of your accretion model.  If you do utilize this model (that remains experimental and hypothetical), you need to specify 

Turbidity Maximum in PPT (the location of the peak turbidity maximum in ppt)
and T Max Zone in ppt (the width of the turbidity maximum effect zone in ppt)

See the figure on page 25 of the technical documentation for more information about this.

Also, play with the Salinity tab on the SLAMM6_Accretion_1-11-2010.xls spreadsheet that is provided in the SLAMM installation directory. 

(2) The accretion model is set up to model a maximum possible accretion rate with various limitation factors.  Therefore, the accretion at the turbidity maximum would be at the maximum rate (if other factors are also maximized, see Eq 10)  The limitation factor when mulitplied by the maximum accretion rate, will provide you with the maximum accretion rate in non turbidity maximum zones.  Again, playing with the spreadsheet and looking at the figure on page 25 should be useful.

Hope this is helpful -- Jonathan


Thanks Jonathan, that was really helpful. The section in the technical documentation made things much clearer too.

Cheers, Karin