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<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009>Hello,</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=526563723-05082009>You
can modify the WRF Fortran code, but a</SPAN></FONT><FONT face=Arial
color=#0000ff size=2><SPAN class=526563723-05082009>re you doing real cases? If
so: </SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=526563723-05082009>1)
<STRONG><FONT face="Times New Roman" color=#000000 size=3>How to set the land
surface to a uniform height at sea level. </FONT></STRONG></SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=526563723-05082009>One
way to do this that doesn't involve modifying the WRF code is to produce a
dataset with the same format as one of the supplied topography datasets, but
containing all zeros. This is rather easy to do with unix commands, for
example</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=526563723-05082009>dd
if=/dev/zero of=my_tmp_outfile bs=2 count=1000 </SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=526563723-05082009>will
produce a binary file called my_tmp_outfile representing 1000 2 byte
integers each containing zero. Just pick one of the existing topographical data
sets supplied with WRF, change 1000 to the correct file size, copy
my_tmp_outfile to files with the appropriate names, and copy the index file. You
will also need to add lines to the GEOGRID.TBL to deal with the new dataset that
you have created, and modify your namelist.wps to use the new
dataset.</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=526563723-05082009>2)
<FONT face="Times New Roman" color=#000000 size=3><STRONG>How to replaces the
land mass with water having a sea surface temperature (SST) set to 301.2 K.
</STRONG><FONT face=Arial color=#0000ff size=2>You can relatively easily produce
a custom landuse dataset that only contains water, similar to producing
the flat topography, but then you have to get into the LANDUSE.TBL etc
and it is a bit of a mess. Another</FONT></FONT> way might be to modify the
met_em files directly. For example you can use a perl script that operates
directly on the CDL (text) specification of the met_em files to modify various
things. eg</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=526563723-05082009>ncdump
met_em_file | my_perl_script | ncgen -o new_met_em_file</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=526563723-05082009>I do
this for various purposes. It is quite slow, and if you want to do a lot of this
then some Fortran or C code that operates directly on a netcdf file would be
better, but if you want a quick and dirty solution then this works fine. Perl is
a good choice for manipulating these text files. Actually if you only want to do
it once or twice then you could even do it by hand. </SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009>Regards</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=526563723-05082009>Chris
</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=526563723-05082009></SPAN></FONT> </DIV>
<BLOCKQUOTE style="MARGIN-RIGHT: 0px">
<DIV></DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT
face=Tahoma size=2>-----Original Message-----<BR><B>From:</B>
wrf-users-bounces@ucar.edu [mailto:wrf-users-bounces@ucar.edu] <B>On Behalf Of
</B>Seshagiri Rao<BR><B>Sent:</B> Wednesday, 5 August 2009 6:28
PM<BR><B>To:</B> wrf users; wrf help<BR><B>Subject:</B> [Wrf-users] Senstive
experiments....<BR><BR></FONT></DIV>
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<TR>
<TD vAlign=top>Dear All,<BR><BR>I read paper in that two experiments are
carried out. May any one from you state how i can do this for WRF model
i am running......<BR><BR>
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<P style="MARGIN-BOTTOM: 0in" align=justify><SPAN
style="FONT-WEIGHT: bold">1) How to set the land surface to a uniform
height at sea level. <BR></SPAN></P>
<P style="MARGIN-BOTTOM: 0in" align=justify><SPAN
style="FONT-WEIGHT: bold"><BR></SPAN></P>
<P style="MARGIN-BOTTOM: 0in" align=justify><SPAN
style="FONT-WEIGHT: bold">2) How to replaces the land mass with water
having a sea surface temperature (SST) set to 301.2 K. </SPAN><BR></P>
<P style="MARGIN-BOTTOM: 0in" align=justify><BR></P>
<P style="MARGIN-BOTTOM: 0in" align=justify>Thanks for help in advance
.....................<BR></P>
<P style="MARGIN-BOTTOM: 0in" align=justify><BR></P>
<P style="MARGIN-BOTTOM: 0in" align=justify>Seshu<BR></P><BR><BR><SPAN
style="COLOR: rgb(255,0,127)">*****************************************
</SPAN><BR style="COLOR: rgb(255,0,127)"><SPAN
style="COLOR: rgb(255,0,127)">K.Seshagiri Rao, </SPAN><BR
style="COLOR: rgb(255,0,127)"><SPAN style="COLOR: rgb(255,0,127)">IITM
Research Fellow, </SPAN><BR style="COLOR: rgb(255,0,127)"><SPAN
style="COLOR: rgb(255,0,127)">Climatology & Hydrometeorology
Division, </SPAN><BR style="COLOR: rgb(255,0,127)"><SPAN
style="COLOR: rgb(255,0,127)">Indian Institute of Tropical Meteorology,
</SPAN><BR style="COLOR: rgb(255,0,127)"><SPAN
style="COLOR: rgb(255,0,127)">Pune -411 008, India. </SPAN><BR
style="COLOR: rgb(255,0,127)"><SPAN
style="COLOR: rgb(255,0,127)">Phone:020-25893600Ext363 </SPAN><BR
style="COLOR: rgb(255,0,127)"><SPAN
style="COLOR: rgb(255,0,127)">Mobile: +91 9850957963. <BR><BR><BR><BR
style="COLOR: rgb(255,0,127)"></SPAN><SPAN
style="COLOR: rgb(255,0,127)">*****************************************</SPAN></TD></TR></TBODY></TABLE><BR></BLOCKQUOTE></BODY></HTML>