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Calculates wavenumber-frequency spectra via seasonal averaging as defined by the US-CLIVAR MJO diagnostics website.

Available in version 5.1.0 and later.


load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"        ; These three libraries are automatically
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"         ; loaded from NCL V6.2.0 onward.
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"     ; No need for user to explicitly load.

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/diagnostics_cam.ncl" ; Still need to load this library.

	function mjo_wavenum_freq_season (
		x       [*][*] : numeric,  
		date       [*] : integer,  
		seasonName [1] : string,   
		opt        [1] : logical   

	return_val  :  array [4][dimsizes(time)/2] 



A two-dimensional variable array containg daily mean values. Nominally: (time,lon).


An integer array containing the date as "YYYYMMDD".


If opt=False, the function will operate under default mode regardless of any attributes associated with the variable.

If opt=True, then the following attributes, associated with opt, may be used to alter the default behavior. Currently, no options are allowed.

Return value

The return variable will be a two-dimensional array containing the wavenumber x frequency spectra.


See the Level 2 diagnostics description: FREQUENCY-WAVE SPECTRA. US-CLIVAR MJO diagnostics website. Click on "Description"; then the Level 2 "See more specific discussion"

The seasons are specified as follows:

      winter (segment) starts Nov 1  [180 days]
      summer (segment) starts May 1  [180 days]
      annual (segment) starts Jan 1  [365 days]

See Also

mjo_spectra, band_pass_area_time,
band_pass_area_time_plot, band_pass_latlon_time,
band_pass_hovmueller, band_pass_hovmueller_plot,
filwgts_lanczos, wgt_areaave, wgt_areaave_Wrap,
wkSpaceTime, wkSpaceTime_cam


See Example 10 of the Madden-Julian Oscillation web page.