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aquaplanet and aerosols

R

rauscher

New Member
Hi-
I have a question regarding how to incorporate (or rather not incorporate) aerosols into aqua-planet simulations. I'm using cesm1_0_1. I've been able to configure and run an aqua-planet simulation. In my simulations, I do not want aerosols to be radiatively active. If aerosols are microphysically active (they do not have to be), they must be fixed in time, zonally symmetric and symmetric about the equator.

I am uncertain about what to change in my namelist (atm_in) and input data files to accomplish this. The namelist that I generate with -use_case "aquaplanet_cam3_cam4" has the following aerosol related sections:

&phys_ctl_nl
cam_chempkg = 'none'

&aerodep_flx_nl
aerodep_flx_datapath = '/usr/projects/cesm/input_data/atm/cam/chem/trop_mozart_aero/aero'
aerodep_flx_file = 'aerosoldep_monthly_1849-2006_1.9x2.5_c090803.nc'
aerodep_flx_type = 'CYCLICAL'
aerodep_flx_ymd = 20000101
/

&prescribed_aero_nl
prescribed_aero_datapath = '/usr/projects/cesm/input_data/atm/cam/chem/trop_mozart_aero/aero'
prescribed_aero_file = 'aero_1.9x2.5_L26_2000clim_c090803.nc'
prescribed_aero_specifier = 'sulf:SO4', 'bcar1:CB1', 'bcar2:CB2', 'ocar1:OC1', 'ocar2:OC2', 'sslt1:SSLT01', 'sslt2:SSLT02',
'sslt3:SSLT03', 'sslt4:SSLT04', 'dust1:DST01', 'dust2:DST02', 'dust3:DST03', 'dust4:DST04'
prescribed_aero_type = 'CYCLICAL'
prescribed_aero_ymd = 20000101
/
&rad_cnst_nl
rad_climate = 'P_Q:H2O', 'D_O2:O2', 'D_CO2:CO2', 'D_ozone:O3', 'D_N2O:N2O', 'D_CH4:CH4', 'D_CFC11:CFC11',
'D_CFC12:CFC12'
/

I think setting rad_climate to not include aerosols will turn off the radiative effect of aerosols (is this the case?), but I am not sure what else to change to 1) either turn off the aerosols (not allow them to act as CCN) or 2) which file should be replaced with a constant, symmetric distribution (most likely aero_1.9x2.5_L26_2000clim_c090803.nc).

Any help (or where to look for more information - I've been going through the namelist and docs) would be great. Full namelist is below.
sara

&aerodep_flx_nl
aerodep_flx_datapath = '/usr/projects/cesm/input_data/atm/cam/chem/trop_mozart_aero/aero'
aerodep_flx_file = 'aerosoldep_monthly_1849-2006_1.9x2.5_c090803.nc'
aerodep_flx_type = 'CYCLICAL'
aerodep_flx_ymd = 20000101
/
&cam3_ozone_data_nl
cam3_ozone_data_on = .false.
/
&cam_inparm
absems_data = '/usr/projects/cesm/input_data/atm/cam/rad/abs_ems_factors_fastvx.c030508.nc'
bnd_topo = '/usr/projects/cesm/input_data/atm/cam/topo/USGS-gtopo30_1.9x2.5_remap_c050602.nc'
del2coef = 3.e+5
div24del2flag = 2
dtime = 1800
fft_flt = 1
filtcw = 0
mfilt = 99
ncdata = '/usr/projects/cesm/input_data/atm/cam/inic/fv/cami_0000-01-01_1.9x2.5_L26_APE_c080203.nc'
nhtfrq = -24
/
&chem_surfvals_nl
ch4vmr = 1.650e-6
co2vmr = 348.0e-6
f11vmr = 0.
f12vmr = 0.
n2ovmr = 0.306e-6
/
&cldfrc_nl
cldfrc_freeze_dry = .true.
cldfrc_ice = .false.
cldfrc_rhminh = 0.800D0
cldfrc_rhminl = 0.910D0
/
&cldsed_nl
cldsed_ice_stokes_fac = 0.5D0
/
&cldwat_nl
cldwat_conke = 5.0e-6
cldwat_icritc = 9.5e-6
cldwat_icritw = 2.0e-4
/
&gw_drag_nl
fcrit2 = 1.0
/
&hkconv_nl
hkconv_c0 = 1.0e-4
hkconv_cmftau = 1800.0D0
/
&phys_ctl_nl
cam_chempkg = 'none'
cam_physpkg = 'cam4'
conv_water_in_rad = 0
deep_scheme = 'ZM'
do_iss = .false.
do_tms = .false.
eddy_scheme = 'HB'
history_microphysics = .false.
microp_scheme = 'RK'
shallow_scheme = 'Hack'
srf_flux_avg = 0
/
&physconst_nl
cpwv = 1.846e3
gravit = 9.79764
mwdry = 28.96623324623746
mwh2o = 18.01618112892741
rearth = 6.37100e6
sday = 86164.10063718943
/
&prescribed_aero_nl
prescribed_aero_datapath = '/usr/projects/cesm/input_data/atm/cam/chem/trop_mozart_aero/aero'
prescribed_aero_file = 'aero_1.9x2.5_L26_2000clim_c090803.nc'
prescribed_aero_specifier = 'sulf:SO4', 'bcar1:CB1', 'bcar2:CB2', 'ocar1:OC1', 'ocar2:OC2', 'sslt1:SSLT01', 'sslt2:SSLT02',
'sslt3:SSLT03', 'sslt4:SSLT04', 'dust1:DST01', 'dust2:DST02', 'dust3:DST03', 'dust4:DST04'
prescribed_aero_type = 'CYCLICAL'
prescribed_aero_ymd = 20000101
/
&prescribed_ozone_nl
prescribed_ozone_datapath = '/usr/projects/cesm/input_data/atm/cam/ozone'
prescribed_ozone_file = 'apeozone_cam3_5_54.nc'
prescribed_ozone_name = 'OZONE'
prescribed_ozone_type = 'CYCLICAL'
prescribed_ozone_ymd = 19900101
/
&rad_cnst_nl
rad_climate = 'P_Q:H2O', 'D_O2:O2', 'D_CO2:CO2', 'D_ozone:O3', 'D_N2O:N2O', 'D_CH4:CH4', 'D_CFC11:CFC11',
'D_CFC12:CFC12'
/
&solar_inparm
solar_const = 1365.0
solar_htng_spctrl_scl = .false.
/
&tropopause_nl
tropopause_climo_file = '/usr/projects/cesm/input_data/atm/cam/chem/trop_mozart/ub/clim_p_trop.nc'
/
&zmconv_nl
zmconv_c0_lnd = 0.0035D0
zmconv_c0_ocn = 0.0035D0
zmconv_ke = 1.0E-6
/
 
E

eaton

CSEG and Liaisons
For the cam4 physics the aquaplanet_cam3_cam4 use case does all that is needed to turn off the effects of aerosols in the simulation, i.e., it removes the aerosol species from the rad_climate variable. The cam4 physics package uses the RK (Rasch and Kristjansson) microphysics which has a prescribed cloud droplet size distribution. The aerosols do not act as CCN in the RK parameterization.

The cam5 physics package is a different story. It uses the MG (Morrison and Gettelman) microphysics which requires aerosols for droplet activation. There is work in progress to construct the zonally symmetric aerosol distribution datasets for proper aquaplanet simulations.
 
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