Problems converting from nc to grib (pressure is negative)
Added by Lars Hole almost 12 years ago
Hi, I need to convert nc-files (output from the ROMS ocean model) to grib in order to run a trajectory model. The files are converted, but I get ta warning that the pressure is below zero, so clearly something goes wrong. Also, when I try to run the trajectory model forced by this grib file, I get a floating point exception, probably caused by the negative pressure. Has anyone run into a similar problem? I only need the surface data, so is it possible to assign a constant value to the pressure? Thanks! Lars
cdo -f grb copy test.nc test.grb
Warning (cgribexDefLevel) : Pressure level of -0.442857 Pa is below zero!
Warning (cgribexDefLevel) : Pressure level of -0.414286 Pa is below zero!
Warning (cgribexDefLevel) : Pressure level of -0.385714 Pa is below zero!
Warning (cgribexDefLevel) : Pressure level of -0.357143 Pa is below zero!
Warning (cgribexDefLevel) : Pressure level of -0.328571 Pa is below zero!
Warning (cgribexDefLevel) : Pressure level of -0.300000 Pa is below zero!
Warning (cgribexDefLevel) : Pressure level of -0.271429 Pa is below zero!
Warning (cgribexDefLevel) : Pressure level of -0.242857 Pa is below zero!
Warning (cgribexDefLevel) : Pressure level of -0.214286 Pa is below zero!
Warning (cgribexDefLevel) : Pressure level of -0.185714 Pa is below zero!
Warning (cgribexDefLevel) : Pressure level of -0.157143 Pa is below zero!
Warning (cgribexDefLevel) : Pressure level of -0.128571 Pa is below zero!
Warning (cgribexDefLevel) : Pressure level of -0.100000 Pa is below zero!
Replies (2)
RE: Problems converting from nc to grib (pressure is negative) - Added by Jaison-Thomas Ambadan almost 12 years ago
Hi Lars,
Can you please upload a sample file of your data (must be < 50MB)? It will be very helpful for the CDO guys here to identify the problem a bit faster! In the mean-time you may have a look at the following thread (CDO handling of ROMS data)
<https://code.zmaw.de/boards/1/topics/913>
Cheers,
J.
RE: Problems converting from nc to grib (pressure is negative) - Added by Lars Hole almost 12 years ago
My nc-files are huge, I am trying to find a way to make them smaller. However, it seems like I may be able to solve the problem using setzaxis and define a new vertical axis. Other suggestions are much appreciated!