[ncl-talk] Problem with wk_spacetime function

[Mike Victor]

*I referred to the code for the function wk_spacetime as given on this link
<http://www.mit.edu/course/13/13.715/ncarg-5.5.1/lib/ncarg/nclscripts/csm/diagnostics_cam.ncl>.
The result of the code is supposed to be in congruence with the methods
used in the paper "Convectively coupled equatorial waves: Analysis of
clouds and temperature in the wavenumber–frequency domain
<https://journals.ametsoc.org/jas/article/56/3/374/24501>", according to
which at first the 3 harmonics of the seasonal cycle are to be removed (as
mentioned in Methodology part of the paper) but according to the code for
wk_spacetime function, they have removed the annual cycle instead. Correct
me if I am understanding it wrong. I am pasting the part of the code where
the annual cycle is removed.*

;-------------------------------------------------------------------
; Remove dominant signals
; (a) Explicitly remove *long term* linear trend
;     For consistency with JET code keep the grid point means.
;     This necessitates that 'dtrend_msg' be used because 'dtrend'
;     always removes the mean(s).
; (b) All variations >= approx 'nDayWin' days if full year available
;-------------------------------------------------------------------

  dNam = getvardims( x )
  work = x($dNam(1)$|:,$dNam(2)$|:,$dNam(0)$|:)    ; reorder  (lat,lon,time)
;;work = dtrend( work , False )   ; remove mean + overall long term
temporal trend
  work = dtrend_msg(ispan(0,ntim-1,1)*1.0, work, False, False)  ;
remove just  trend
  if (isatt(work,"_FillValue")) then
      delete(work at _FillValue)                  ; dtrend_msg adds this att
  end if
                                                         ; replace
with detrended
  x    = (/ work($dNam(0)$|:,$dNam(1)$|:,$dNam(2)$|:) /) ; values (time,lat,lon)
  delete(work)

  if (nDayTot.ge.365) then                     ; rmv dominant signals
      rmvMeans = False                         ; original code did not remove
      x = rmvAnnualCycle(x, spd, nDayTot, rmvMeans, fCrit, 0)
  end if

  if (debug) then
      print("===> Post removal of trend and signal <===")
      printVarSummary( x )                     ; (time,lat,lon)
      printMinMax( x, True )
  end if


*Please help.*
*Regards.*
*Mayuresh *
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