<div dir="ltr"><div><div><div><div>Of course you can interpolate a coarse grid to a high resolution grid.<br></div>However, the high-resolution grid *does not contain any additional information" then the original grid. Just more values.<br><br></div>ncl-talk is not going to tell you what method to use. You should try both bilinear and conservative<br></div>and compare ... do difference plots. This is how you learn.<br><br></div>Generally, for the tyoe of varuiable you are interpolating ... conservative is the better approach.<br><br><div><div><div>==<br><br></div><div>If you are new to NCL, ***please read the documentation***<br><br><a href="http://test.www.ncl.ucar.edu/Document/Manuals/">http://test.www.ncl.ucar.edu/Document/Manuals/</a><br><br><a href="http://test.www.ncl.ucar.edu/Document/Manuals/language_man.pdf">http://test.www.ncl.ucar.edu/Document/Manuals/language_man.pdf</a><br><br></div><div>An excellent tutorial by DKRZ is here<br><br><a href="https://dl.dropboxusercontent.com/u/8357888/homepage/tutoriais/ncl/NCL_Tutorial_V1.1.pdf">https://dl.dropboxusercontent.com/u/8357888/homepage/tutoriais/ncl/NCL_Tutorial_V1.1.pdf</a><br></div><div><a href="https://dl.dropboxusercontent.com/u/8357888/homepage/tutoriais/ncl/NCL_Exercises_and_Tasks_all.pdf">https://dl.dropboxusercontent.com/u/8357888/homepage/tutoriais/ncl/NCL_Exercises_and_Tasks_all.pdf</a><br><br></div><div>It is your responsibility to put forth the effort to learn the language.<br><br></div><div>Good Luck<br></div><div><div><br><br><br><br></div></div></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jun 10, 2016 at 8:45 AM, Mary Haley <span dir="ltr"><<a href="mailto:haley@ucar.edu" target="_blank">haley@ucar.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_default" style="font-size:small">Samy,</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">I'm not sure what you mean by your question. Are you asking how to compare whether the regridding is correct or not? </div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">If you use ESMF regridding, and you have NCL V6.3.0, then you can set </div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small"> Opt@Check = True</div><div class="gmail_default" style="font-size:small"><br></div><div class="gmail_default" style="font-size:small">This turns on the "--check" option in the regridding, which the ESMF folks describe as:</div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><br></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"> "This
option performs a regridding operation on an analytic field using the
weights and computes both the interpolation error and the conservation
error (if used with a conservative interpolation method). These errors
are then output to the user. "</font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif"><br></font></div><div class="gmail_default"><font face="arial, helvetica, sans-serif">The output will look like this:</font></div><div class="gmail_default" style="font-size:small"><span style="font-family:Arial,Verdana,sans-serif;font-size:12px"><br></span></div><div class="gmail_default" style="font-size:small"><div class="gmail_default"> Grid 1 min: 1.0001662906361517 Grid 1 max: 2.9998337097885632 </div><div class="gmail_default"> Grid 2 min: 1.0004992779714816 Grid 2 max: 2.9995007220286158 </div><div class="gmail_default"> </div><div class="gmail_default"> Maximum negative weight = 0.0000000000000000 </div><div class="gmail_default"> Maximum positive weight = 0.74984053650072569 </div><div class="gmail_default"> </div><div class="gmail_default"> Mean relative error = 1.9234096383084854E-004</div><div class="gmail_default"> Maximum relative error = 4.4673574673482763E-003</div><div class="gmail_default"> Least squares error = 2.4340317596281900E-004</div><div class="gmail_default"> </div><div class="gmail_default"> Grid 1 area = 0.0000000000000000 </div><div class="gmail_default"> Grid 2 area = 0.0000000000000000 </div><div class="gmail_default"> Conservation error = 0.0000000000000000 </div><div class="gmail_default"><br></div><div class="gmail_default">--Mary</div><div class="gmail_default"><br></div></div></div><div class="gmail_extra"><br><div class="gmail_quote"><div><div class="h5">On Thu, Jun 9, 2016 at 7:36 AM, <span dir="ltr"><<a href="mailto:ratebsamy@yahoo.com" target="_blank">ratebsamy@yahoo.com</a>></span> wrote:<br></div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div class="h5"><div><div style="color:#000;background-color:#fff;font-family:times new roman,new york,times,serif;font-size:16px"><div>Hello NCL Team,</div><div><br></div><div dir="ltr">Good afternoon. I am samy ashraf a phd student in ICTP institute and have the output for carbon cycle parameters from CMIP5 on coarse resolution (3.75 x 2.5 degree for example) and I want to regrid it to high resolution (0.5 x 0.5) degrees using <a href="http://www.ncl.ucar.edu/Document/Functions/Contributed/area_conserve_remap_Wrap.shtml" target="_blank"><strong>area_conserve_remap_Wrap</strong></a> in order to compare it with gridded observation data on 0.5 x 0.5, so my question is the regridding is correct or not?</div><div dir="ltr"><br></div><div dir="ltr">Thanks in advance</div><div dir="ltr"><br></div><div dir="ltr">Best</div><span><font color="#888888"><div dir="ltr"><br></div><div dir="ltr">Samy </div></font></span></div></div><br></div></div>_______________________________________________<br>
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