I'm running simulations with CAM4 for planets with different rotation periods, and want to output two fields (surface pressure and downwelling top-of-atmosphere shortwave flux) at an interval such that I have data over a semi-diurnal and diurnal time period. For a 24-hr rotation period, following this website - http://www.cesm.ucar.edu/models/ccsm4.0/ccsm_doc/x2500.html - I've modified the file cam.buildnml.csh to output this data hourly, every 24 hours, like this:

fincl2 = 'PS:I','FSDTOA:I'

nhtfrq = 0,-1

mfilt = 1,24

This works for a 24-hr (Earth-like) rotation period. I get hourly data, and each day's .nc file contains 24 hours worth of data, which I can plot over a semi-diurnal (12 hours) and diurnal period. But for simulations at rotation periods of 25 days, 50 days or 100 days (for example), I'm stuck. How should I modify 'nhtfrq' and 'mfilt' to make sure I have data output over a full rotational period, if the periods are longer than one Earth day? If I leave it as above, is CAM taking the relevant length of the day into account (I've specified the length of the day in Earth days in the SourceMods/src.cam/zenith.F90), and dividing 25 days (for example) by 24, making every "hour" equal to 1+ day? Or should it be modified to be something like this:

fincl2 = 'PS:I','FSDTOA:I'

nhtfrq = 0,-24 (output every 24 hours)

mfilt = 1,25 (write 25 time samples to each history file)

I've tried the above, but am not sure I'm getting data over a full "day" (25, 50, or 100 Earth days). I'd appreciate any help trying to figure this out.

Thanks,

Aomawa

Dr. Aomawa Shields

NSF Astronomy and Astrophysics Postdoctoral Fellow

UC President's Postdoctoral Program Fellow

TED Fellow

UCLA Department of Physics and Astronomy

Harvard-Smithsonian Center for Astrophysics