[ncl-talk] Simultaneous correlation between 2 variables

[Dennis Shea]

[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

Please do not respond to me directly. ncl-talk only.
Good Luck

On Tue, Jan 9, 2018 at 12:12 AM, Sujata Mandke via ncl-talk <
ncl-talk at ucar.edu> wrote:

> Dear NCL community,
> Greetings!
>
>  I am trying spatial plot of simultaneous correlation between
>  monthly SST and monthly rainfall data.  However, SST and
> rainfall data have different horizontal resolutions. Also time
> axis of the two datasets are different. Rainfall data has time
> defined on first of each month while SST has mid-month (16th)
>  date for monthly mean data.
>
>         My questions are as follows
> (i)Before calculation of correlation, do i need to interpolate
>  one of the data sets to the horizontal resolution of the
> other. (higher resolution to lower resolution data set.).
> If so, which regridding function shall be used for
> regular longitude/latitude grid interpolation.
>
> I searched NCL website and also seen decision tree
> figure, but could not find suitable function for my requirement.
>
> (ii)Is Function “escorc” suitable for simultaneous correlation?
>
> (iii)Do i need to make time axis definitions also same
>  before calculating correlation between the two? As time
> axis definitions in rainfall and SST datasets are different.
>
> I am using NCL version 6.1.2 on linux operating system.
> Please help in this regard.
> Any suggestion would be of great help.
>
> With best regards
> Dr. (Mrs) Sujata Mandke
> Scientist, Indian Institute of Tropical Meteorology
> Pashan, PUNE-411008.
> _______________________________________________
> ncl-talk mailing list
> ncl-talk at ucar.edu
> List instructions, subscriber options, unsubscribe:
> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ucar.edu/pipermail/ncl-talk/attachments/20180109/80c776a4/attachment.html>