[MITgcm-support] pickup file for ptracer

[David Ferreira]

Hi Yu-Kun,
pickup_somTRAC01* contains the 1st and 2nd order moments of the tracer (you must be using the Prather scheme for tracer advection). These moments capture the sub grid scale distribution of the tracer, but from memory, they sum up to zero. The mean concentration of the tracer at the grid-scale is contained in the normal pickup pickup_ptracers.ckptA.

So as long as you don;t want to touch the subgridscale distribution, you should be able to work with the pickup_ptracers.ckptA only, the moments will adjust as the simulation carries on.

cheers,
david

________________________________
From: 钱钰坤 [qianyk at mail3.sysu.edu.cn]
Sent: Tuesday, May 23, 2017 5:54 AM
To: MITgcm-support
Subject: [MITgcm-support] pickup file for ptracer

Hi all,

When I was ready to hack the pickup files of ptracer, I found that there are two files: pickup_ptracers.ckptA.data and pickup_somTRAC01.ckptA.data.  It is easy for me to hack the content of pickup_ptracer.ckptA.data, but I am not sure it would be enough to restart the model leaving the pickup_somTRAC01.ckptA.data unchanged.

I've searched the manual and even googled for the purpose of pickup_somTRAC01* files but found nothing.  The corresponding meta file shows that nrecords is 9, indicating 9 variables without specifying their variable names.  A quick search through the code shows me that these files contains statistics of the moment (SOM?) for the ptracers, but I am not sure.

Can anyone tell me more details about the file pickup_somTRAC*?  If I want to hack the content of pickup files for ptracers, do I need to hack the pickup_somTRAC* files accordingly so that both pickup files are read by the model in a consistent sense?

Thanks in advance.


------------------
Best regards

Yu-Kun Qian (钱钰坤)
Center for Monsoon and Environment Research
Department of Atmospheric Sciences
School of Environmental Science and Engineering
Sun Yat-sen University
No. 135 Xingang West Road, Haizhu District
Guangzhou, 510275, P.R. China
Tel; 020-84115227
Email: qianyk at mail3.sysu.edu.cn<mailto:qianyk at mail2.sysu.edu.cn>


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