[ncl-talk] Wind Swath Calculation using NCL

Dennis Shea shea at ucar.edu
Mon May 11 13:52:07 MDT 2020


Looks correct to me.

Keep in mind that satellite swath data can be quite noisy.

You can do a simple test at one lat/lon location.

  nl  = 600                       ; arbitrary ... your choice
  ml = 700                       ;     "                    "

  ws_min  = *min*(ws(:,nl,ml))
  ws_max = *max*(ws(:,nl,ml)

  print(WS)   ; all 287 values
  print("====")                         ; visual separator
  print("ws_min  ="+ws_min )
  print("ws_max ="+ws_max )
  print("swath="+swath(nl,ml))   ; should match 'ws_max'

On Mon, May 11, 2020 at 1:16 PM Sakib Ahmed via ncl-talk <ncl-talk at ucar.edu>
wrote:

> Dear NCL Community,
>
> I'm trying to calculate the maximum wind swath(maximum wind speed at each
> grid point for all the time steps) from a model output but after plotting,
> it doesn't look correct. It would be helpful if anyone can point me if
> there's anything wrong with the code that I'm using.
>
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
> begin
>
> f    = addfile("florence_wind.nc" ,"r" )   ; reading file
> ws = f->ws                                          ; reading variable
> printVarSummary(ws)
>
> Variable: ws
> Type: float
> Total Size: 1658634992 bytes
>             414658748 values
> Number of Dimensions: 3
> Dimensions and sizes:   [287] x [1202] x [1202]
> Coordinates:
> ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;calculate
> swath;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
>
> swath = dim_max_n(ws,0)   ; swath(nlat,nlon)
>
> printVarSummary(swath)
>
> Variable: swath
> Type: float
> Total Size: 5779216 bytes
>             1444804 values
> Number of Dimensions: 2
> Dimensions and sizes:   [1202] x [1202]
> Coordinates:
>
> end
>
> Thank you in advance for the help.
> Sakib
>
> Sakib Ahmed
> Connecticut College
> Environmental Studies Major,
> New London, CT 06320
>
>
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