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<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof">hi Steven,</span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof"><br>
</span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof">if you are using opengrads.org (has both 'user defined functions
and commands') then I would recommend using the 're' function which is the C version of my original regrid2.f 'user defined function' </span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof"><br>
</span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof">re() offers more options for doing the regrid and will automatically
use a 3<span><sup>rd</sup> order bessel interpolator going from large -> small grids, but an area-weighted integral preserving method for small->large grids. suppose the 2.5 is in file 1 and the 2.0 is in file 2, then you could:</span></span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof"><span><br>
</span></span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof"><span>slpdiff=re(slp.1,2.5)-re(slp.2,2.5) # regrid to a common
2.5 degree grid. or re(slp.1,2.0)-re(slp.2,2.0) or re(slp.1,1.0)-re(slp.2,1.0)...</span></span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof"><span><br>
</span></span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof"><span>I'd also check the global mean using</span></span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof"><span><br>
</span></span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof"><span>'d aave(slp.1,g)'</span></span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof"><span>...</span></span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof"><span>and the diffs ('d aave(slpdiff,g)')</span></span></div>
<div class="elementToProof"><span style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);" class="elementToProof"><span><br>
</span></span></div>
<div class="elementToProof" style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">
hope this help</div>
<div class="elementToProof" style="font-family: Calibri, Arial, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);">
Best /R Mike</div>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> gradsusr <gradsusr-bounces@gradsusr.org> on behalf of Steven Young <shy9@earthlink.net><br>
<b>Sent:</b> Sunday, December 18, 2022 17:33<br>
<b>To:</b> gradsusr@gradsusr.org <gradsusr@gradsusr.org><br>
<b>Subject:</b> [gradsusr] Comparing data baases with different resolution</font>
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<p class="x_MsoNormal">I am looking at two SLP databases with different resolution, one is 2.5 x 2.5 and the other is 2.0 x 2.0. Is there a way to calculate/plot the difference between the two?</p>
<p class="x_MsoNormal">Thanks</p>
<p class="x_MsoNormal">Steven Young</p>
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