id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
364	Updated balance operator input parameters	arango	arango	"Updated the balance operator to specify its input parameters from the '''s4dvar.in''' script:

{{{
! Number of iterations in the biconjugate gradient algorithm used to solve
! the elliptic equation for sea surface height in the error covariance
! balance operator, [1:Ngrids].

          Nbico == 200

! Parameters used to compute balanced salinity in terms of temperature using
! empirical T-S relationships in the error covariance balance operator,
! [1:Ngrids].

       dTdz_min == 0.001d0                ! minimun dT/dz (Celsius/m)
       ml_depth == 100.0d0                ! mixed-layer depth (m; positive)
}}}

Notice that we need as many '''Nbico''' iterations are required to decrease the error value of the reference free-surface to 1E-8 or smaller. In many applications '''Nbico=200''' will do the job.

'''Warning''': be aware that there are 4 arrays that are allocated using '''Nbico''' and its value maybe constrained by available memory:
 * FOURDVAR(ng) % p_r2d (LBi:UBi,LBj:UBj,Nbico(ng))
 * FOURDVAR(ng) % r_r2d (LBi:UBi,LBj:UBj,Nbico(ng))
 * FOURDVAR(nd) % bp_r2d(LBi:UBi,LBj:UBj,Nbico(ng))
 * FOURDVAR(ng) % br_r2d(LBi:UBi,LBj:UBj,Nbico(ng))

All the values are needed in the backward iterations of the adjoint.

I also corrected couple of bugs. Many thanks to Andy more fore reporting and correcting these problems.
"	upgrade	closed	major	Adjoint Based Algorithms	Adjoint	3.3	Done