MLD reaches bottom

[Chan Joo Jang <cjjang@xxxxxxxxxxx>]

Dear Ferreters:

I would like to set the mixed layer depth (MLD) to bottom depth when 
MLD reaches the final depth with a valid value.
How can I express this in Ferret(version 5.22)?
Thanks in advance. Jang

ps)  I posted the same question to this user group without any responses.
=====

Following is a Ferret script which I used to calculate MLD based on
temperature difference.

% cat mld_feb.jnl
cancel mode verify
set mode metafile mld_feb.plt
!===============
! EXP CR
!===============
set data temp_cr.nc
let sst=temp[k=1]
let mls=abs(temp-sst)
let mld=mls[z=@loc:1.0]
let sbad=MISSING(temp,0)
define viewport/xlimits=0.15:0.5/ylimits=0.5:0.9 v1
set viewport v1
go margins 0.0 0.0 0.0 0.0
fill/set/l=2/nolab/lev=(-10,1000,70) missing(mld,-10)
ppl xlab " " !LONGITUDE
ppl ylab LATITUDE
ppl fill
shade/over/nolab/pal=grey/lev=(0)/l=1/k=1 sbad
label 140 55 0 0 0.35 MLD in Feb. (DT=1)
label 130 48 0 0 0.28 EXP CR
cancel data_set 1


Information for the NetCDF file which I used.

% ncdump -ch temp_cr.nc

netcdf temp_cr {
dimensions:
longitude = 96 ;
latitude = 114 ;
level024 = 24 ;
time = UNLIMITED ; // (12 currently)
variables:
float longitude(longitude) ;
longitude:long_name = "Longitude values" ;
longitude:cartesian_axis = "X" ;
longitude:units = "degrees_E" ;
longitude:ipositive = 1 ;
float latitude(latitude) ;
latitude:long_name = "Latitudes values" ;
latitude:cartesian_axis = "Y" ;
latitude:units = "degrees_N" ;
latitude:ipositive = 1 ;
float level024(level024) ;
level024:long_name = "Level values" ;
level024:cartesian_axis = "Z" ;
level024:units = "level" ;
level024:ipositive = 1 ;
level024:positive = "up" ;
double time(time) ;
time:long_name = "Time coordinate values" ;
time:cartesian_axis = "T" ;
time:units = "months since 1900-01-01 00:00:00.0" ;
time:ipositive = 1 ;
time:calendar_type = "Gregorian" ;
float temp(time, level024, latitude, longitude) ;
temp:long_name = "temp(deg. C)" ;
temp:units = "unknown" ;
temp:valid_range = -1.e+37f, 1.e+37f ;
temp:missing_value = 1.e+20f ;

// global attributes:
:title = "Simulated temperature (EXP CR)" ;
:Conventions = "COARDS" ;
:GFDL_NCIR_VER_NO = "0.7" ;
:missing_value = 1.e+20f ;
}


--

Chan Joo Jang, Ph.D., Senior researcher 
(cjjang@kordi.re.kr,http://ogcm.kordi.re.kr)
Korea Ocean Research and Development Institute
1270 Sa1-dong, Ansan  425-744, Korea
Phone 82-31-400-6317 FAX 82-31-408-5823