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The output variable "NO_Lightning" in CAM6

baih

New Member
Hello,

I was trying to output the variable "NO_Lightning" (lightning NO source) from CAM6, but the outputted values are always zero.

I used F2000climo compset and added "NO_Lightning" to user_nl_cam fincl1 without changing any source code. The output files were successfully generated and other variables looked good (non-zero). I wonder if there's any Namelist setting needed to turn on the calculation of "NO_Lightning"?

Any insight would be appreciated.

Thanks,
Hedanqiu
 

nusbaume

Jesse Nusbaumer
CSEG and Liaisons
Staff member
Hi Hedanqiu,

I believe the issue is that the default chemistry package for CAM6 (trop_mam4) doesn't have NO or XNO as a chemical species, and thus has no lightning production. I am not sure what kind of science experiment you are looking to simulate, but in order to generate values for "NO_Lightning" I believe you need to implement a more advanced version of chemistry, like "trop_mozart".

Modifying the chemistry package can be done by appending the line -chem XXX to CAM_CONFIG_OPTS in env_build.xml, where XXX is your chemistry package of interest, e.g. trop_mozart.

Finally, I am moving this thread to the CAM-chem forum, as they will likely be able to provide significantly more information about the chemistry packages themselves then I can.

Hope that helps, and have a great day!

Jesse
 

baih

New Member
Hi Jesse,

Thank you very much for your reply! I basically wanted to look at the lightning NOx source as well as the intermediate variables (such as flash rate, cloud height) with which the model calculates NOx source.

Have a good day,
Hedanqiu
 

baih

New Member
Hi Hedanqiu,

I believe the issue is that the default chemistry package for CAM6 (trop_mam4) doesn't have NO or XNO as a chemical species, and thus has no lightning production. I am not sure what kind of science experiment you are looking to simulate, but in order to generate values for "NO_Lightning" I believe you need to implement a more advanced version of chemistry, like "trop_mozart".

Modifying the chemistry package can be done by appending the line -chem XXX to CAM_CONFIG_OPTS in env_build.xml, where XXX is your chemistry package of interest, e.g. trop_mozart.

Finally, I am moving this thread to the CAM-chem forum, as they will likely be able to provide significantly more information about the chemistry packages themselves then I can.

Hope that helps, and have a great day!

Jesse
Hi,

I appended "-chem trop_mozart" to CAM_CONFIG_OPTS, but got the following error message:

open_trc_datafile:
/glade/p/cesmdata/cseg/inputdata/atm/cam/ozone/tracer_cnst_CAM6chem_2000climo_3D_monthly_c171004.nc
trcdata_init: file%has_ps = T
O3 is not an invariant
ERROR: tracer_cnst_init


Any further thoughts on that?

Thanks a lot,
Hedanqiu
 

nusbaume

Jesse Nusbaumer
CSEG and Liaisons
Staff member
Hi Hedanqiu,

That error appears to be due to an issue with how the namelist is configured. To avoid that problem, you can use one of the CESM CAM-Chem compsets (which to be honest I should have recommended earlier, sorry about that). These compsets are all labeled FCXXX, where XXX represents additional information like the year of interest. For your simulation, I believe you can re-create your case using the FC2000climo compset and you should have all the chemistry processes and variables you need, but with the same model physics and boundary conditions that you have for your current simulation. Of course if that still doesn't work just let us know.

Thanks, and hope that helps!

Jesse
 
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