<div dir="ltr">Hi Nikhil:<br><br>As far as I know there are two ways to compress/reduce the size of wrf.out files:<br><br>(i) The easy method is via the namelist.input files:<br><br> &time_control<br>…<br> iofields_filename = "my_iofields_list.txt","my_iofields_list.txt",<br> ignore_iofields_warning = .true.,<br><br>Where my_iofields_list.txt is an ascii file containing e.g.,:<br><br>-:h:0:tlwdn,tlwup,slwdn,slwup,tswdn,tswup,sswdn,sswup,p_hyd<br>-:h:0:hailnc,hml,huml,hvml,isltyp,ivgtyp,lai,lu_index,mapfac_m,mapfac_mx<br><br>which removes (-:h) the variables in the list (tlwdn,tlwup,slwdn...etc) rom the history stream 0 (:0) at runtime.<br><br>(ii) NCO operators. One can get a factor of 12 decrease in file size by using packing (converting reals to scaled 16-bit integers) + compression, or about a factor 4-5 for just compression.<br><br>ncpdq -O -7 -L 2 wrfout_d02_2012-08-28_12:01:00 <a href="http://wrfoutest.nc">wrfoutest.nc</a><br>Result:<br>-rw-r--r-- 1 joe staff 3.4G Mar 23 2014 wrfout_d02_2012-08-28_12:01:00<br>-rw-r--r-- 1 joe staff 254M Oct 24 13:41 <a href="http://wrfoutest.nc">wrfoutest.nc</a><br><br><br>ncks -7 -L 2 wrfout_d02_2012-08-28_12:01:00 <a href="http://wrfoutest_nopack.nc">wrfoutest_nopack.nc</a><br>Result:<br>-rw-r--r-- 1 joe staff 3.4G Mar 23 2014 wrfout_d02_2012-08-28_12:01:00<br>-rw-r--r-- 1 joe staff 699M Oct 24 13:46 <a href="http://wrfoutest_nopack.nc">wrfoutest_nopack.nc</a><br><br><br>Combining (i) and (ii) would naturally yield the best results.<br><br>Cheers and hope this helps,<br><br>-- <br>-------------------------------------------------------------<br>Alexandre Fierro, PhD<br>Research Scientist-<br>National Severe Storms Laboratory (NSSL/NOAA)<br><b style="font-weight:normal">The Cooperative Institute for Mesoscale Meteorological
Studies</b> (OU/NOAA)<br>Los Alamos National Laboratory, Los Alamos, NM (LANL)<br><br>"Yesterday is History, Tomorrow is a Mystery and Today is a Gift; That is why it is called the Present" <br><br>"There are only 10 types of people in the world:<br>Those who understand binary, and those who don't" <br><br>"My opinions are my own and not representative of OU, NSSL,<br>AOML, HRD, LANL or any affiliates."<br> ^.^<br> (o o)<br> /( V )\<br> ---m---m----<br><div class="gmail_extra"><br><div class="gmail_quote">On 29 July 2015 at 03:53, Nikhil Garg <span dir="ltr"><<a href="mailto:nikhilgarg.gju@gmail.com" target="_blank">nikhilgarg.gju@gmail.com</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><br></div><div>I am assuming that you want to save physical space, I was wondering why not try netcdf4 for wrf model. It works with WRF model version 3.5 and above. Although WRF 3.4.1 can be compiled with nc4 option it doesnt seem to work atleast for my case and I use nccopy for compression, but i have tested and it works fine in 3.6 version.</div><div><br></div><div>I know that it is not really an answer to your question but it does </div><div>save you effort needed for compression using nccopy.</div></div><div class="gmail_extra"><br><div class="gmail_quote">On 28 July 2015 at 16:31, Jatin Kala <span dir="ltr"><<a href="mailto:jatin.kala.jk@gmail.com" target="_blank">jatin.kala.jk@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi all,<br>
Just wondering if anyone has any experience in modifying the WRF I/O<br>
source code to do "Lossy" compression for the wrfout_d0* files, i.e.,<br>
something along the lines of storing say temperatures as integer with a<br>
scale factor to convert to float again later when analyzing the outputs.<br>
<br>
I already know about NetCDF's nccopy, just wondering if someone has been<br>
brave enough to try "Lossy" type compression within the WRF source code,<br>
excluding wrfrst_d0* files.<br>
<br>
Cheers,<br>
Jatin.<br>
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</font></span></blockquote></div><span class="HOEnZb"><font color="#888888"><br><br clear="all"><div><br></div>-- <br><div><div dir="ltr"><div>Regards<br></div><div><br></div>Nikhil <br><br><div>-------------------------------------------------------------------</div><div><font style="background-color:rgb(255,255,255)" color="#000000" face="comic sans ms, sans-serif">Big whirls have little whirls,</font></div><div><font style="background-color:rgb(255,255,255)" color="#000000" face="comic sans ms, sans-serif">Which feed on their velocity,</font></div><div><font style="background-color:rgb(255,255,255)" color="#000000" face="comic sans ms, sans-serif">And little whirls have lesser whirls,</font></div><div><font style="background-color:rgb(255,255,255)" color="#000000" face="comic sans ms, sans-serif">And so on to viscosity</font></div><div><font color="#ff0000" face="trebuchet ms, sans-serif">(Richardson, 1922)</font></div></div></div>
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