prescribed aerosols in CAM4 and cam5

[mahowald@cornell_edu]

Hi!

I would like to set up new files to prescribe the aerosols in both CAM4/BAM and CAM5/MAM versions. Is there any scripts or help is getting the input datasets set up or guidance on what should be there that is easy to supply me? E.g. whatever script created the input files we use now? Of course, I am mostly interested in the dust.

Thanks
Natalie

 

[rneale]

Hi Natalie, There are not tools on hand to generate these datasets as far as I know. Jean-Francois created the CAM4 datasets and Po-Lun Ma (PNNL) is heading up the prescribed aerosol effort for CAM5 and this is nearly complete. Maybe you could contact them for tools and hopefully we can make these available at least for CAM5.ThanksRich

 

[eaton]

I did some of the final assembly of the CAM4/BAM datasets, but I don't have any general purpose scripts for doing this.  I was gluing together files from JF that contained decadal average data.  I used NCO operators to concatenate the datasets and to update the time, date, and datesec variables to give consistent time coordinate info.  My advice is to use the existing datasets as a template and just update the data as appropriate.

 

[lamar]

Brian's description is accurate.  Nothing was done on the data except for decadal averaging, done using NCO operators.

 

[po-lun_ma@pnnl_gov]

Prescribing MAM aerosols in CAM5 requires writing out additional fields in the parent run (the prognostic aerosol run) first. Then, same as procedures done for prescribed aerosols in CAM4-BAM, simple NCO commands to do decadal averages of monthly means are all we need. We are updating the prescribed MAM code currently and will upload the code/script/data very soon.

 

[drosa@lbl_gov]

I am interested in running cam4 with prescribed aerosols in amip mode and later in slab ocean. Starting with amip ... I modified the namelist use case cam4_bam_radpsv_geos5.xml to have a fixed solar constant, prescribed sst, prescribe aerosols (from merra assimilation), and prescribed ozone which i averaged the original dataset on the years 1994-2000. I was able to see in the output the optical depth of the aerosols but I need to check the magnitude of the forcing. I added the rad_diag_1 expecting the variables "_RF" to appear but they did not. How does it work now?Thank youd my new use case is:  20060101
  1361.31

  /global/scratch2/sd/drosa/Data/Aerosols
  aero_1.9x2.5_L26_CYC_MERRA.nc
  CYCLICAL

  /global/scratch2/sd/drosa/Data/atm/cam/ozone/
  ozone_rcp26_v1_1.9x2.5_L26_2006.nc
  O3
  CYCLICAL

 
    'A:Q:H2O', 'N:O2:O2', 'N:CO2:CO2', 'N:ozone:O3', 'N:N2O:N2O', 'N:CH4:CH4', 'N:CFC11:CFC11', 'N:CFC12:CFC12',
    'N:sulf:/project/projectdirs/ccsm1/inputdata/atm/cam/physprops/sulfate_camrt_c080918.nc',
    'N:dust1:/project/projectdirs/ccsm1/inputdata/atm/cam/physprops/dust1_camrt_c080918.nc',
    'N:dust2:/project/projectdirs/ccsm1/inputdata/atm/cam/physprops/dust2_camrt_c080918.nc',
    'N:dust3:/project/projectdirs/ccsm1/inputdata/atm/cam/physprops/dust3_camrt_c080918.nc',
    'N:dust4:/project/projectdirs/ccsm1/inputdata/atm/cam/physprops/dust4_camrt_c080918.nc',
    'N:bcar1:/project/projectdirs/ccsm1/inputdata/atm/cam/physprops/bcpho_camrt_c080918.nc',
    'N:bcar2:/project/projectdirs/ccsm1/inputdata/atm/cam/physprops/bcphi_camrt_c080918.nc',
    'N:ocar1:/project/projectdirs/ccsm1/inputdata/atm/cam/physprops/ocpho_camrt_c080918.nc',
    'N:ocar2:/project/projectdirs/ccsm1/inputdata/atm/cam/physprops/ocphi_camrt_c080918.nc',
    'N:SSLTA:/project/projectdirs/ccsm1/inputdata/atm/cam/physprops/ssam_camrt_c080918.nc',
    'N:SSLTC:/project/projectdirs/ccsm1/inputdata/atm/cam/physprops/sscm_camrt_c080918.nc'
 

  2000

  .true.
  2006
  2006

 

[andrew]

We actually do have some scripts. These were used to convert the IPCC RCP emissions files into MAM input files. But they may not be fully relevant for dust.They are in the subversion repository in:  https://svn-ccsm-models.cgd.ucar.edu/tools/proc_atm/CreateModalAeroInput/The other option is to simply take the current files, and modify them off line as you wish.  

 

[eaton]

The radiative forcing calculation that was present in the CAM3 model version was removed because it was incomplete (it was only implemented in the shortwave part of the code).  The recommended way to get radiation diagnostics from the old CAM radiation code used by the cam4 physics package is via the PORT tool which has some user documentation herehttps://wiki.ucar.edu/pages/recentlyupdated.action?key=portAnd is described in a paper here:http://www.geosci-model-dev-discuss.net/5/2687/2012/gmdd-5-2687-2012.pdf 

 

[drosa@lbl_gov]

Thank you. I had that info from Andrew too.The procedure says to use instantaneous output every 73 time steps and then to average over a year. I am looking the the first run and I see a signal only where there is insolation. I guess the yearly averaging makes everything uniform. But ... Is there a way to get the monthly/daily forcing?

 

[andrew]

I assume that if you average over shorter periods you will get monthly or daily forcing (might have to increase the frequency of output to get daily).

 

[drosa@lbl_gov]

I would think the same but in the procedure it says to use instantaneous output. You cannot do daily output with that. Was it ever used for daily forcing calculation using average output?

 

[andrew]

I think you will need to do more frequent intstantaneous output to average. You could try to calculate a 'diurnal mean' profile, but I would not recommend that (it requrires the right solar zenith angle, etc)

 

[pjc@llnl_gov]

Hi Daniele,You can output it every timestep if you want (instead of every 73), then you can average over whaterever periods you want.   However, this will produce output very quickly, which is why 73 is suggested.  Note that 73 is not generally a multiple of the number of timesteps in a day, so it will sample all the different solar zenith angles.

 

[drosa@lbl_gov]

Thanks, Philip.Are these the only fields needed for PORT? 
    'FLNT','FLNR','FLNS','FSNT','FSNR','FSNS','QRS','QRL'
 

 

[pjc@llnl_gov]

Hi Daniele,No, those are not needed at all.   What PORT needs are the temperatures, pressures, concentrations, and cloud quantities necessary to repeat the radiation calculations (including recalculating the quantities you list).     The advantage of PORT is that you can change somthing like CO2 concentration to calculate the radiative forcing that would imply.To get the output, what you do is set a flag in the CAM namelist.   By memory it is DO_RAD_OUTPUT=true.   If it is supported in your version of CAM, then it will automatically create extra output files (usually cam.h1 files) that contain everything you will need to run PORT.Best wishes,      Philip  

 

[drosa@lbl_gov]

Hi Philip,on the documentation at https://wiki.ucar.edu/display/port/PORT?src=contextnavchildmode there is rad_driver_output. Probably that one?In any case, they are not used by cesm1_2_0:drosa@hopper07:~/Code/cesm1_2_0> grep -ri rad_driver_output *
drosa@hopper07:~/Code/cesm1_2_0> grep -ri DO_RAD_OUTPUT *maybe I am not using the right version of cesm.daniele(update 20140426)I found the namelist: rad_data_output 

 

[drosa@lbl_gov]

During the validation I got this:

 aerodynamic parameter error in UrbanFluxes
 h_u - z_d

 

[apgrass]

I had a similar problem and got it to work by setting the compset to CAM with all other components stubs. See my comment here: https://bb.cgd.ucar.edu/comment/1007794#comment-1007794

 

[drosa@lbl_gov]

I followed apgrass suggestion and it's running but here is another thing. I set it to run for 5 days: start_ymd = 20060101
 stop_n = 5
 stop_option = 'ndays'

but, instead, it continues running until it gets killed by the job scheduler. In the atm log I find:
  ********** Time Manager Configuration **********
   Calendar type:            NO_LEAP
   Timestep size (seconds):           1800
   Start date (yr mon day tod):              2006            1            1
            0
   Stop date (yr mon day tod):               2006            1            6
            0
   Reference date (yr mon day tod):          2006            1            1
            0
   Current step number:                505
   Current date (yr mon day tod):            2006            1           11
        45000
  ************************************************
WSHIST: writing time sample   5 to h-file 2 DATE=2006/01/11 NCSEC= 45000

Any idea?

 

[drosa@lbl_gov]

At this stage I have the radiative forcing from PORT. I see the optical depth of the aerosols is available in the MASTER list. The only missing thing is the single scattering albedo that was also available in CAM3.5. Is it anywhere in cesm1_2 or PORT?