[MITgcm-support] tracer concentration

[Angela Marie Zalucha]

The tracers are passive.

There is no change in atmospheric mass with time.

There are no sources and sinks of tracers.


   Angela



On Thu, 24 Feb 2011, Yuan Lian wrote:

> Are you running the ptracers package with passive tracers? Is any change in 
> the atmospheric mass if
> the tracer is passive? Do you have any sink or source of tracers? I don't see 
> much problems
> with most of the advection schemes for passive tracers, though some deviation 
> exists but should be
> smaller than 0.1% in most cases.
>
> If the total atmospheric mass is changing, make sure the tracer mixing ratio 
> is updated properly
> (i.e, scaling the mixing ratio in columns).This should also work if the 
> tracer is semi-passive, i.e., the
> mass loading of tracer is considered in the model.
>
> If you have sink and source of tracers, make sure they are self-consistent. 
> Or if you are updating tracer
> tendencies in physics grid, make sure the schemes are conservative.
>
> Cheers,
> Yuan
>
>
>
> On 2/24/11 1:17 PM, Angela Marie Zalucha wrote:
>> Hello, I am working with the ptracers package.  I am finding that after 
>> running for about 5 days, the tracers are not conserving mass at all--the 
>> increase in mass is about 50%, which is pretty significant.  I am using 
>> advection scheme 81 (I have tried 7, 30, 33, 77, 80, but with similar 
>> results).  Is this typical?  Are there any ways around this?
>> 
>> Thanks,
>>   Angela
>> 
>> _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-
>> Angela Zalucha, Ph.D.
>> Postdoctoral Associate
>> Department of Earth, Atmospheric,
>>   and Planetary Sciences
>> Massachusetts Institute of Technology
>> 
>> Office located at Southwest Research Institute
>> 1050 Walnut Street, Suite 300
>> Boulder, CO 80302
>> USA
>> (720) 208-7211
>> 
>> 
>> http://web.mit.edu/azalucha/www/index.html
>> _-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-
>> 
>> 
>> 
>> 
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>
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_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-
Angela Zalucha, Ph.D.
Postdoctoral Associate
Department of Earth, Atmospheric,
   and Planetary Sciences
Massachusetts Institute of Technology

Office located at Southwest Research Institute
1050 Walnut Street, Suite 300
Boulder, CO 80302
USA
(720) 208-7211


http://web.mit.edu/azalucha/www/index.html
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