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band_pass_area_time_plot

Generate a plot using the output from band_pass_area_time.

Available in version 5.1.0 and later.

Prototype

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.

	procedure band_pass_area_time_plot (
		x    [3][*] : numeric,  ; [3][time]
		time    [*] : numeric,  
		pltDir  [1] : string,   
		pltType [1] : string,   
		pltName [1] : string,   
		opt     [1] : logical   
	)

Arguments

The variable returned from band_pass_area_time.

time

The "time" associated with each time step. Generally, this is the same as x&time but this is not required.

pltDir

The directory to which the output will be directed. The current directory is indicated by diro="./"

pltType

Graphical type to be generated: "png", "x11", "ps", "eps", "pdf", "ncgm".

pltName

The name associated with the generated graphic.

opt

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

If opt=True, then attributes associated with opt may be used to alter the default behavior.

Currently, no options are available.

Description

Using the variable returned from band_pass_area_time, and its attributes, this procedure will generate multiple time series on a panel plot.

Examples

The following example focuses on the Madden-Julian Oscillation [MJO]. However, this function is general purpose and can be applied to any spatial time series. It can be used to focus on other periods of interest.

Example 1

Consider daily "olr". Extract MJO (Madden-Julian Oscillation) information using the 20-to-100 day band pass period and 201 weights as suggested by the WMO CLIVAR Working Group.

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/diagnostics_cam.ncl"


  f     = addfile("...", "r") 
  x     = f->OLR                 ; (time,lat,lon) , ntim=1461

  latS  = -10.              ; select region
  latN  =  10.
  lonL  =  60.              ; Indian Ocean
  lonR  = 280.              ; East Pacific

  spd   = 1                 ; daily means
  bpf   = (/20,100,201/)    ; MJO ... suggested by MJO WG [WMO] 
  wgty  = latRegWgt(x&lat, "double", 0) 
  opt   = False
                            ; pass in area of interest
  mjo_area = band_pass_area_time (x(:,{latS:latN},{lonL:lonR} \
                                ,spd, bpf, wgty({latS:latN}), opt)

  printVarSummary( mjo_area )
  printMinMax( mjo_area, True)

The edited output (currently) looks like:

       Variable: mjo_area
       Number of Dimensions: 1
       Dimensions and sizes:  [var | 3] x [time | 1461]
       Coordinates:
                  time: [17479080..17514120]
       Number Of Attributes: 18
        units :       W/m2
        long_name :   filtered: weighted area avg: Daily OLR
        band_pass_start :     20
        band_pass_last :      100
        band_pass_Nwgts :     201
        var_0:                band pass
        var_1:                raw areal means
        var_2:                local variances
       
        filtered: weighted area avg: Daily OLR: min=-6.58817   max=5.37212

band_pass_area_time_plot

Prototype

Arguments

Description

See Also

Examples