ViewVC logotype

Diff of /MITgcm/doc/diags_changes.txt

Parent Directory Parent Directory | Revision Log Revision Log | View Revision Graph Revision Graph | View Patch Patch

revision 1.2 by dimitri, Mon Jun 22 03:14:37 2009 UTC revision 1.3 by jmc, Sun Apr 4 14:28:20 2010 UTC
# Line 1  Line 1 
1    ================================================================
2    Apr 03, 2010
3    1) add diagnostics for KPP non-local flux of Temp, Salt and pTracers
4     (respectively: KPPg_TH, KPPg_SLT and KPPgTrXX for tracer number XX)
5    This allows to close the tracer budget when using KPP.
7    2) Change the diagnostic for KPP non-local term:
8     name:          description:
9    KPPghat         Nonlocal transport coefficient (s/m^2)
10                    (correspond to KPP ghat field, from which the non-local
11                    flux of tracer (T,S,pTr) is computed, as the product of
12                    ghat , KPPdiffKz and surface flux.)
13    replaced by:
14    KPPghatK        ratio of KPP non-local (salt) flux relative to surface-flux
15                    (correspond to the product: KPP_ghat * KPPdiffKzS
16                     which gives the fraction of the the surface flux of Salt
17                     that KPP return as non local flux; also valid for any passive
18                     tracer, but could be different for Temp., see comment below)
20    comments (from mitgcm-devel list):
21     I was also tempted to replace the KPPghat diagnostics
22     with something more useful which incorporates the KPPdiffKz:
23     Since it is the product KPPghat*KPPdiffKz which matters,
24     and given that short time variations of both (which have no
25     reason not to be correlated) can be significant,
26     the product of the 2 time-ave is very likely to be quiet
27     far from the time-ave of the product.
28     It has also the advantage of a simpler interpretation:
29     the product is just the fraction of the surface flux which is
30     treated as non local (no unit, instead of this funny s/m^2
31     for KPPghat).
33     Then I would propose to just pick one KPPdiffKz (for instance,
34     KPPdiffKzS for salinity, since it's also used for Ptracers),
35     and have only 1 diag: "KPPghatK" for KPPghat*KPPdiffKzS (no unit).
37     For temperature (KPPghat*KPPdiffKzT), it's probably not too different
38     from the one computed for salinity (might be in fact a better
39     time-ave value that what we have now, for the reason above).
40     And to get a precise diagnostic of KPP-non-local effect
41     on temperature, there would be this new diagnostic directly from
42     kpp_transport_t.F (which can be used to close a Temp. budget).
44    ================================================================
45  Jun 21, 2009  Jun 21, 2009
46  Some redundancies and relations for model diagnostics:  Some redundancies and relations for model diagnostics:

Removed from v.1.2  
changed lines
  Added in v.1.3

  ViewVC Help
Powered by ViewVC 1.1.22