<p>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.</p>

<p>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.</p>

<p>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. </p>

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

CC BY-SA 3.0
2017-10-28T13:30:59.383Z
Hi, I am using RAMS model for my present study. The initial and boundary conditions are provided from NCEP FNL analysis data.
Agni
CC BY-SA 3.0
2017-10-28T15:17:53.077Z
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.
AtmosphericPrisonEscape
CC BY-SA 3.0
2017-10-31T05:48:51.627Z
I'm voting to close this question as off-topic because this is a question specific to one software.
Wolfgang Bangerth
CC BY-SA 3.0
2017-11-11T16:45:36.083Z
@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 :-/
Semidiurnal Simon
<atmosphere-modelling><tropical-cyclone>
NaN values of aerosol variables in KF/Kuo parametrization schemes
Agni
# NaN values of aerosol variables in KF/Kuo parametrization schemes

(Asked by: username_0 on 2017-10-28)

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.

**Tags:** atmosphere-modelling, tropical-cyclone

> **Comments:**
> **username_0**: Hi, I am using RAMS model for my present study. The initial and boundary conditions are provided from NCEP FNL analysis data.  
> **username_1**: 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.  
> **username_2**: I'm voting to close this question as off-topic because this is a question specific to one software.  
> **username_3**: @username_2 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 :-/  

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