[aspect-devel] Progress in writing the mantle convection code Aspect

[Magali Billen]

Hmm? Are they improved with better resolution? What is there magnitude?

For a density or compositional field, its okay to have very local smearing between fields, as this is probably
more realistic anyway, but if you have over/undershoots that become unstable  (for temperature in particular)
then that will ruin the simulation.
-Magali


On Oct 16, 2013, at 11:50 AM, Eric Heien wrote:

> FYI, the Aspect advection scheme still has over/undershoots.  Not as severe as CitcomS but they definitely appear and affect the simulation.
> 
> -Eric
> 
> On Oct 16, 2013, at 11:43 AM, Magali Billen wrote:
> 
>> Hi Katrina,
>> 
>> I agree with Wolfgang that using active fields is a better choice for this (sorry - one of the
>> many things we need to be talking about as you get more into ASPECT). I talked with
>> Wolfgang about this at some meeting (?) a couple years ago.  Using active fields will
>> be much less costly computationally than using tracer particles.  In CitcomS, we can't
>> using active fields because the advection scheme that is there for temperature (which
>> one might copy for active fields) leads to over/undershoots at the field boundaries 
>> when you have a non-diffusive field.  The scheme in ASPECT is quite different and my
>> understanding is that it doesn't have this problem.
>> 
>> Magali
>> 
>> On Oct 15, 2013, at 11:13 AM, Wolfgang Bangerth wrote:
>> 
>>> 
>>> Hi Katrina,
>>> 
>>>> I'm hoping to have active particles (or fields?) that define layers
>>>> within a plate, with assigned densities that affect the model. In
>>>> CitcomS, I model bouyant basaltic crust, harzburgite and dense eclogite
>>>> layers that move with the subducting plate and affect its total bouyancy
>>>> over periods of >30 Ma. I hope that helps.
>>> 
>>> Interesting.
>>> 
>>> This is already possible using active fields. Take a look at the cookbook section in the model -- it has an example of an active field that is used to model the density as a function of composition.
>>> 
>>> Best
>>> W.
>>> 
>>> 
>>> -- 
>>> ------------------------------------------------------------------------
>>> Wolfgang Bangerth               email:            bangerth at math.tamu.edu
>>>                              www: http://www.math.tamu.edu/~bangerth/
>>> 
>>> _______________________________________________
>>> Aspect-devel mailing list
>>> Aspect-devel at geodynamics.org
>>> http://geodynamics.org/cgi-bin/mailman/listinfo/aspect-devel
>> 
>> _______________________________________________
>> Aspect-devel mailing list
>> Aspect-devel at geodynamics.org
>> http://geodynamics.org/cgi-bin/mailman/listinfo/aspect-devel
>