[ncl-talk] Simultaneous correlation between 2 variables

[Sujata Mandke]

Respected Dennis Shea sir,

   Thanks for your prompt reply to my queries.

[3] Which spatial interpolation function? What type of grids are the two data sets on? If both are rectilinear, then 'linint2_Wrap' could be used.
>Both the variables are on Fixed grids. (Latitude x Longitude)

[5] For monthly mean files the 'time' should represent the temporal center-of-mass of the observations (ie: mid-month). However, many times the file's creators indicate the time by the 1st day of the month. So, who knows? It is your responsibility to find this information. My speculation is that the time is just a place-holder.
>I found this information. One variable has time as 1st day of month while
other variable has time as mid-month day (16th of the month). My guess is
that for calculation of simultaneous temporal correlation,
 this difference in time definition may be problem.

Once again thanks for your help.
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[1] spatial interpolation: yes, both grids must be the same size & shape.
[2] Interpolating a low resoluion grid to a high resolution grid just yields the low resolution information on a grid with more points.
      Generaly, interpolate the high res to low res grid
[3] Which spatial interpolation function? What type of grids are the two data sets on? If both are rectilinear, then 'linint2_Wrap' could be used.
     More complicated grids should use the ESMF regridding
[4] escorc is specifically for 'contemporaneous' correlation
[5] For monthly mean files the 'time' should represent the temporal center-of-mass of the observations (ie: mid-month). However, many times the file's creators indicate the time by the 1st day of the month. So, who knows? It is your responsibility to find this information. My speculation is that the time is just a place-holder.
[6] NCL 6.1.2 was released February, 2013. It is almost 5 years old. Many NCL enhancements have bee mad. I suggest that you uograde to NCL 6.4.0
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With best regards
Dr.(Mrs) Sujata Mandke
scientist, Indian Institute of Tropical Meteorology,PUNE.