Sea Surface Temperatures in MOM-SIS

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Lachlan Stoney

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Jan 4, 2017, 1:14:11 AM1/4/17
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Dear Users,

Is anyone able to clarify how SSTs are handled in MOM(5)-SIS? Looking at the code, I'm finding it difficult to answer the following questions:


- Do the atmospheric boundary conditions (CORE-II) directly influence the SSTs or do they directly influence the temperatures at 5m depth? Or both?


- In terms of the model physics, what is the difference between the SSTs and 5m temperatures?


- Is there feedback between the SSTs and the 5m temperatures?


For a bit of context, I'm trying to figure out if the 5m depth level can experience warming from vertical mixing with a relatively warm surface layer, assuming that the warm surface layer is generated by direct communication with a relatively warm atmosphere. In this case T(air) > T(surface) > T(5m depth).

Any help would be greatly appreciated.

Cheers,

Lachlan.

Stephen Griffies

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Jan 8, 2017, 11:00:06 AM1/8/17
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Hi,

"SST" is the value of the temperature field at k=1, no matter what the thickness of the top grid cell.  This is the cell that directly feels the surface boundary conditions.  

Stephen 



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Russ Fiedler

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Jan 23, 2017, 1:43:36 AM1/23/17
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Hi,

I'd just like to alert the community that there are some very strange
choices for the valid ranges of common variables. These choices
determine the values (scale_factor and add_offset) used for packing
variables into 16 bit integers and can result in massive degradation of
precision.

Unfortunately, some of these choices changed from mom4p1 to mom5 and we
got caught using some old diagnostic tables. In particular, various sea
surface height variables had their ranges changed from +/-10m to
+/-1000m. This resulted in an effective resolution of 3cm and severely
compromised what we could do with the output. Ouch! Also mixed layer
depths have a range from 0-1000km resulting in a resolution of about 15m!

In short, if you are considering the use of the packing option in mom5,
be very careful and check the default ranges in the code since it is
rather likely that they haven't been sanity checked.

I guess it would be nice if the valid range could be overridden by the
diagnostic table but that may be difficult.

Russ

Nicholas Hannah

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Jan 23, 2017, 5:16:36 AM1/23/17
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Ross, 

Thanks for this. Is there anything that should be fixed in the MOM code, scripts or settings?

Nic



Russ

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