Changes between Version 7 and Version 8 of ticket/0663_MLF

Timestamp:

2010-04-24T15:39:29+02:00 (14 years ago)

Author:

gm

Comment:

--

ticket/0663_MLF

@@ +1 @@
+[[PageOutline]]
+
 Last edited [[Timestamp]]
 
-[[PageOutline]]
-
-=== Author ===
- Matthieu Leclair & Gurvan Madec 
-
+=== '''Author  :''' Matthieu Leclair & Gurvan Madec  ===
 ----
-=== Branch ===
-DEV_r1837_MLF
+=== '''Branch :'''  DEV_r1837_MLF ===
 ----
 
@@ -26 +23 @@
 The 3 main modifications concern : 
 
-'''(1) The forcing terms'''. They are defined as a mean between time step n-1/2 and n+1/2 (sbcmod.F90, sbc.F90, trasbc.F90, dynzdf....F90)
+   [[BR]]
+
+'''(1) The forcing terms'''. They are defined as a mean between time step n-1/2 and n+1/2 
+
+   modules involved : sbc_oce.F90, sbcmod.F90, trasbc.F90, traqsr.F90, dynzdf....F90
  
-[[Image(NEW_LF_RA.jpg, 50%)]][[BR]]
-Illustration of forcing integration methods. Old formulation (top) and new formulation (bottom).
+   [[Image(NEW_LF_RA.jpg, 50%)]][[BR]]
+   Illustration of forcing integration methods. Old formulation (top) and new formulation (bottom).
 
    At each time a forcing term appears in the 3 time evolution equations solved in NEMO/OPA (ssh, dynamics and tracer). The mean of kt+1/2 and kt+1/2 has to be used in order to remove the largest source of divergence of two consecutive time step. Therefore, the surface module (including the sea-ice!) must now provide both kt+1/2 and kt-1/2 forcing fields, and all the module involving a forcing term have to be modified.
    Note that TKE equation is solved with a two level time stepping scheme : no need of a before field for its forcing term (i.e. taum)
 
-   '''sbc_oce.F90 :''' add "before" forcing fields (denoted by a '_b' sufix) for all ocean forcing components (utau_b, vtau_b, qns_b, qsr_b, emp_b, emps_b)
+   [[BR]]
+
+   '''sbc_oce.F90 :''' add "before" forcing fields (denoted by a '_b' sufix) 
+      All ocean forcing components are involved, i.e.  utau_b, vtau_b, qns_b, qsr_b, emp_b,and  emps_b
+
+   [[BR]]
    
    '''sbcmod.F90 :''' add the swap of surface fields and the read/write in the restart file.
@@ -42 +48 @@
       CAUTION : here the swap must be done at each kt, what ever the nn_fsbc value is. Otherwise the ocean forcing will be wrong.
 
-   '''trasbc.F90''' : applied heat and freshwater/salt fluxes (qns, emp, emps) as the mean of 2 consecutive time-steps (kt+1/2 and kt-1/2)
 
-      This involes the following changes : (1) incorporate the time mean of the forcing ; (2) put the IF-ELSE-ENDIF outside the DO-loop for vector optimisation ; (3) remove the key_zco optimisation (increase readability) as zco is less and less used ; (4) correct a bug in vvl case, where salt flux associated with freezing/melting were not taken into account.
+   [[BR]]
+   '''trasbc.F90''' : change in the heat and freshwater/salt fluxes 
+      The thermohalin fluxes (qns, emp, emps) are now applied as the mean of 2 consecutive time-steps (kt+1/2 and kt-1/2). This involes the following changes : (1) incorporate the time mean of the forcing ; (2) put the IF-ELSE-ENDIF outside the DO-loop for vector optimisation ; (3) remove the key_zco optimisation (increase readability) as zco is less and less used ; (4) correct a bug in vvl case, where salt flux associated with freezing/melting were not taken into account.
 
       CAUTION 1 : bug in the salt flux in key_vvl ===> modif in limsbc_2.F90 (emps becomes a salt flux in vvl,limsbc, limsbc_2 and CICE interface must be modified)
@@ -50 +57 @@
       CAUTION 2 : bug in with no solar light penetration (ln_traqsr=.false.) ==> modif in trasbc : qns = qns + qsr.
 
+   [[BR]]
+
+
+   '''traqsr.F90 : ''' applied the solar heat flux (qsr) as the mean of 2 consecutive time-steps (kt+1/2 and kt-1/2)
+
+      CAUTION 1 : the case where the light penetration is provided by the bio-model ( i.e. lk_qsr_bio = ln_qsr_bio =.true. is not yet treated. It probably requires changes in p4zopt.F90 and trcopt.F90. Not completely obvious since this depends on the TOP time-stepping strategy.
+
+   [[BR]]
+
+
+   '''dynzdf_exp.F90 : ''' applied the stress (utau, vtau) as the mean of 2 consecutive time-steps (kt+1/2 and kt-1/2)
+
+   [[BR]]
+
+
+   '''dynzdf_imp.F90 : ''' applied the stress (utau, vtau) as the mean of 2 consecutive time-steps (kt+1/2 and kt-1/2)
+
+   [[BR]]
+
+
 
 '''(2) The Asselin filter''' remove the forcing from the filter (dynnxt (?), tranxt, traqsr)
+
+[[BR]]
+
+
 
 '''(3) The semi-implicit hpg'''.
@@ -64 +95 @@
    The change extend further the stability limit of the time stepping scheme when ln_dynhpg_imp = T
 
+   [[BR]]
+
+
 '''N.B.''' : Three key elements of the LF-RA scheme have already been implemented in former version of NEMO (v3.0 and v3.1). As a remainder, there are:
 
@@ -73 +107 @@
 
 
+----
 === Pending issues ===
 
@@ -106 +141 @@
 
  * Processor configurations tested
- * etc----
+ * etc
 
+----
 === Bit Comparability ===
 ||Does this change preserve answers in your tested standard configurations (to the last bit) ?||!'''YES/NO !'''||