I am using the numerical weather prediction (NWP) model RAMS to simulate a Tropical Cyclones in BoB region. I made two setups with two Cumulus Parametrization schemes (Kuo and KF). Initial and boundary conditions data were generated from NCEP FNL analysis data.

Here, I am facing a problem of getting NaN values of aerosol/microphysics variables with both the schemes. With the KF scheme, these are obtained at an early stage i.e. at time of KF CP update time (or twice of this time). Whereas, the Kuo scheme provides this error after 3 hours of model initialization.

Initially, I thought that this might be due to the 'timestep'. I rechecked it many times by increasing and decreasing its value but the problem persisted.

I also checked the microphysics parameters set according to my knowledge, I could not find the cause of this error.

  • 1
    $\begingroup$ unless you tell which NWP model it is how does one proceed to help you ? $\endgroup$
    – gansub
    Oct 28 '17 at 11:09
  • $\begingroup$ Hi, I am using RAMS model for my present study. The initial and boundary conditions are provided from NCEP FNL analysis data. $\endgroup$
    – Agni
    Oct 28 '17 at 13:30
  • 1
    $\begingroup$ I don't think we can solve your problem here, such things need to be debugged on the spot. However we can maybe give some general guidelines what to look out for: Taking square roots of negative numbers, dividing by zero etc. are prominent producers of NaNs. So check if you get negative densities/concentrations/pressures or where the denominator in your numerical schemes becomes very small. $\endgroup$ Oct 28 '17 at 15:17
  • 4
    $\begingroup$ I'm voting to close this question as off-topic because this is a question specific to one software. $\endgroup$ Oct 31 '17 at 5:48
  • $\begingroup$ @WolfgangBangerth IMHO that isn't a problem, so long as the software is specific to earth science. So I don't think it's off topic. I do think, however, that it's unlikely to get a useful answer here :-/ $\endgroup$ Nov 11 '17 at 16:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.