[CIG-LONG] Thermally driven counterflow

[Magali Billen]

Hello Karen,
I'm cc'ing this to CIG-long in case others meet the same problem.
I'm also cc'ing my post-doc Pierre Arrial in case he checks his e-mail.
Magali

On Aug 9, 2010, at 3:26 PM, Karen Paczkowski wrote:

> Hi Magali,
>
> Thank you for getting back to me.  You're right, that is probably  
> the problem.  I had been confused on how to send my temperature  
> profile to the hydrostatic term since there was nowhere to specify  
> my temperature cut off (Tmax in the TemperatureProfile function) in  
> the hydrostatic term.  I unfortunately don't know how to recompile  
> the code, but I may be able to fix the problem just by changing how  
> I define the thermal structure so it matches how the hydrostatic  
> term handles a temperature profile.
>
> Do you know if your post-doc tried this before changing the source  
> code?
>  Did they run into problems doing this or did they just find it  
> easier to change the source code?

I don't know if he tried that or not. We wanted to use an error  
function so he changed the code instead.

>
> Thank you!
> Karen
>
> On Aug 9, 2010, at 5:09 PM, Magali Billen wrote:
>
>> Hi Karen,
>>
>> I believe that my post-doc may have encountered a similar problem  
>> (he is unfortunately away on vacation
>> at the moment).  The issue was that he was defining the initial  
>> thermal structure using an error function
>> and plate age. However, the thermal profile used in computing the  
>> hydrostatic term is hard-coded in
>> as an exponential function of depth. The difference in the thermal  
>> profiles led to an effective buoyant temperature anomaly at the  
>> base of the plate which caused upward flow. He changed the code to  
>> use the same
>> error function profile and the issue disappeared.
>>
>> Magali
>>
>>
>> On Aug 9, 2010, at 1:58 PM, Karen Paczkowski wrote:
>>
>>> Hi,
>>>
>>> Thank you for all the help.  I am unfortunately still getting a  
>>> very unexpected flow field.  The only velocities I have set are:
>>>
>>> Vx = 0 and Vy = -Vslab on the left side
>>> Vy=0 across the top
>>>
>>> My input file is producing a flow field that flows in the opposite  
>>> direction as Vslab (up and to the right) and has a magnitude 2-3  
>>> orders of magnitude larger than Vslab.  This was not occurring  
>>> prior to adding the thermal field, so I am assuming it has to do  
>>> with that, but I'm really not sure what is causing this exactly.   
>>> I have attached a picture of the velocity field and a copy of the  
>>> input file.  It is written for Gale 1.5.0.  I would really  
>>> appreciate any advice.
>>>
>>> Thank you,
>>> Karen
>>>
>>> <VerticalSlab_withThermalField.pdf>
>>>
>>>
>>> <VerticalSlab_ThermalField.pdf>
>>>
>>>
>>> <VerticalSubduction_ThermalField.xml>
>>>
>>>
>>>
>>>
>>>
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>