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Namelist parameters associated with atmosphere schemes

chemUCI and Linoz v3

Parameter Description Default value*
airpl_emis_file Aviation emission
chlorine_loading_file Chlorine loading
chlorine_loading_fixed_ymd
chlorine_loading_type
ext_frc_specifier 3-D emissions
ext_frc_cycle_yr
ext_frc_type
srf_emis_specifier Surface emissions
srf_emis_cycle_yr
srf_emis_type Upper bound of mean raindrop diameter
linoz_data_file Linoz data file
linoz_data_cycle_yr
linoz_data_path
linoz_data_type
lght_no_prd_factor Lightning NOx emission factor 5.0
fstrat_efold_list Tracer (from troposphere) list with e-folding decay in the stratosphere
  • Many of these namelist parameters specify input data files. Check the atm_in file for examples or refer to the Users' Guide.

Cloud Layers Unified By Binormals

Parameter Description Default value
gamma_coef Width of vertical velocity within a Gaussian PDF component at low skewness 0.12
gamma_coefb Width of vertical velocity within a Gaussian PDF component at high skewness 0.28
C8 Coefficient of damping of third moment of vertical velocity, w’3 5.2
C1 Coefficient of damping of second vertical moment of vertical velocity, w’2, at low skewness 2.4
C14 Coefficient of damping of second horizontal moments of vertical velocity, u’2 and v’2 2.0
c_k10 Ratio of diffusivity of momentum to heat 0.35

Dust aerosol

Parameter Description Default value
dust_emis_scheme1 The v3 dust emission scheme (Kok et al., 2014) 22

HOMME

Parameter Description Default value
se_tstep Main dycore timestep.3 [seconds] resolution dependent4
nu Tensor hyperviscosity coefficient, independent of spatial resolution. [1/s] 3.4e-8
nu_top Scalar viscosity at model top. [m^2/s] resolution dependent5
transport_alg Select between semi-lagrangian and Eulerian based transport schemes 126
statefreq print a variety of dycore metrics to the atm.log file every “statefreq” timesteps 480
vert_remap_alg Algorithm used to remap the vertically lagrangian levels back to the reference levels 107
se_ftype Controls how physics tendencies are applied.8 2
Parameter Description Default value
is_output_interactive_volc Switch for diagnostic output of the stratospheric aerosol optics .false.
mam_amicphys_optaa flag to use new time-splitting treatment of H2SO4 production and loss 1
n_so4_monolayers_pcage Number of monolayers required to age primary-carbon mode particles 3
seasalt_emis_scale Tuning parameter for sea salt emission 0.55

OCEANFILMS

Parameter Description Default value
mam_mom_cycle_yr 1
mam_mom_datapath Path that contains the files specified in mam_mom_filelist 'atm/cam/chem/trop_mam/marine_BGC/'
mam_mom_filename File name that contains a sequence of files for prescribed mom concentrations.9 'monthly_macromolecules_0.1deg_bilinear_latlon_year01_merge_date.nc'
mam_mom_rmfile Flag to remove the file containing prescribed aerosol deposition fluxes from local disk. FALSE
mam_mom_specifier Names of variables containing aerosol data in the prescribed aerosol datasets. 'chla:CHL1','mpoly:TRUEPOLYC','mprot:TRUEPROTC','mlip:TRUELIPC'
mam_mom_datatype Type of time interpolation for data in mam_mom files.10 'CYCLICAL'
mam_mom_cycle_yr Cycle year for prescribed aerosol flux data if mam_mom_type='CYCLICAL'.11 1
mam_mom_fixed_ymd Date at which prescribed aerosol flux data is fixed if mam_mom_type='FIXED'.12 0
mam_mom_fixed_tod The time of day (seconds) corresponding to mam_mom_fixed_ymd 0
mam_mom_bubble_thickness Bubble film thickness (in m) for marine organic aerosol emission mechanism.13 0.1e-6
mam_mom_mixing_state Switch to select mixing state assumption in marine organic aerosol code.14 0 [Note: set to 3 in the atm_in namelist]
mam_mom_parameterization Selection of alternate parameterizations for marine organic matter emissions.15 1

Note: non-default values have not been carefully tested and may not work as expected.

Predicted Particle Properties

Parameter Description Default value
do_prescribed_ccn Turn on the prescribed CCN if true false
micro_aerosolactivation Turn on aerosol activation if true true
micro_p3_lookup_dir Directory of P3 look-up tables inputdata/atm/cam/physprops
micro_p3_tableversion P3 look-up table Version 4.1.2
micro_subgrid_cloud Sub-grid cloud properties true
micro_tend_output Output of P3 microphysical process rates false
p3_accret_coeff Tunable parameter for adjusting rain accretion efficiency 117.25
p3_autocon_coeff Tunable parameter for adjusting droplet autoconversion efficiency 30500
p3_embryonic_rain_size Radius of embryomic raindrops from auto-conversion 0.000025 (m)
p3_max_mean_rain_size Upper bound of mean raindrop diameter 0.005 (m)
p3_mincdnc Lower bound of droplet number concentration 20.d6 (# m-3)
p3_nc_autocon_expon Nc exponent in droplet auto-conversion -1.1
p3_qc_accret_expon Qc exponent in rain accretion 1.15
p3_qc_autocon_expon Qc exponeent in droplet autoconversion 3.19
p3_wbf_coeff Tunable parameter for adjusting WBF efficiency 1.0
do_cooper_inp3 Turn on Cooper ice nucleation scheme if true false

Rapid Radiative Transfer Model for GCMs

Parameter Description Default value
iradsw Frequency for updating shortwave fluxes and heating rate.16 -1
iradlw Frequency for updating longwave fluxes and heating rate.17 -1
irad_always Length of time in timesteps (irad_always>0) or hours (irad_always<0).18 0
use_rad_dt_cosz Flag to use radiation dt for all cosz calculations.19 .true.
spectralflux Calculate fluxes (up and down) per band .false.
liqcldoptics Choice of cloud optical property parameterization for liquid clouds.20 gammadist
icecldoptics Choice of cloud optical property parameterization for ice clouds.21 mitchell

Zhang and McFarlane deep convection scheme

ZM Parameters Description Default value
zmconv_ke Tunable evaporation efficiency in ZM deep convection scheme 2.5E-6
zmconv_tau Relaxation time in ZM deep convection scheme 3600
zmconv_dmpdz Parcel fractional mass entrainment rate -0.7E-3
zmconv_alfa Initial downdraft mass flux fraction 0.14D0
zmconv_tiedke_add Temperature perturbation of an air parcel 0.8D0
zmconv_cape_cin Number of negative buoyancy regions that are allowed 1
zmconv_clos_dyn_adj Flag to apply mass flux adjustment to ZM convection scheme true
zmconv_trig_dcape Enable dynamic CAPE (DCAPE) trigger for ZM deep convection .false.
zmconv_trig_ull Enable unrestricted launch level (ULL) mode for ZM deep convection .false.
Conv. micro. Parameters Description Default value
zmconv_microp Convective microphysics option in ZM convection scheme true
zmconv_auto_fac Cloud droplet-rain autoconversion enhancement factor 7.0
zmconv_accr_fac Cloud droplet-rain accretion enhancement factor 1.5
zmconv_micro_dcs Autoconversion size threshold for cloud ice to snow (m) 150.E-6
MCSP Parameters Description Default value
zmconv_mcsp_heat_coeff MCSP heating coefficient 0.3
zmconv_mcsp_moisture_coeff MCSP moisture coefficient 0.0
zmconv_mcsp_mom_coeff MCSP momentum coefficient (fraction of storm-relative shear 0.0
zmconv_mcsp_use_full_shear MCSP use full (u,v) shear vector instead of zonal-only shear .false.

Cloud Feedback Model Intercomparison Project (CFMIP) Observation Simulator Package

Parameter Description Default value
cosp_lite Flag to enable several options for lightweight COSP.22 false

Orographic drag schemes

Parameter Description Default value
use_gw_oro Flag to enable linear orographic gravity wave drag. true
do_tms Flag to enable Turbulent Mountain Stress (TMS). false
effgw_oro Efficiency of orographic gravity waves. 0.375
tms_orocnst Turbulent mountain stress parameter. 1.0
tms_z0fac TMS factor for determining z_0 from orographic std deviation. 0.75
use_od_ls Flag for new nonlinear oGWD.23 false
use_od_bl Flag for Flow-blocking drag (FBD) scheme. false
use_od_ss Flag for small-scale GWD (sGWD) scheme. false
use_od_fd Flag for Turbulent orographic form drag (TOFD) scheme. false
od_ls_ncleff Tuning parameter for nonlinear oGWD.24 3
od_bl_ncd Tuning parameter for FBD.25 3
od_ss_sncleff Tuning parameter for sGWD.26 1

  1. This parameter is set in user_nl_drv ↩

  2. Use 1 to revert to the v1/v2 scheme ↩

  3. Additional parameters control the hyper viscosity, tracer and vertical remap timesteps, which are derived from se_tstep. ↩

  4. Scales linearly with horizontal resolution. ↩

  5. Value is either resolution dependent, or static when laplace_scaling=1 ↩

  6. semi-lagranian method with monotonicity and mass preservation ↩

  7. strict monotonicity applied on top of a 2nd order accurate PPM method ↩

  8. 0=”dribbled” in during dynamics timesteps. 1=”hard adjustment” after each physics timestep. 2=hybrid approach: hard adjustment for tracers, dribbled for remaining tendencies ↩

  9. The filenames in this file are relative to the directory specified by mam_mom_datapath. ↩

  10. Can be set to 'CYCLICAL', 'SERIAL', 'INTERP_MISSING_MONTHS', or 'FIXED'. ↩

  11. Only if , Format: YYYY ↩

  12. Format: YYYYMMDD ↩

  13. The physically reasonable range is approximately (0.1 - 1) x 10^ -6. ↩

  14. Currently implemented options: 0 : total external mixture, add to mass; 1 : total external mixture, replace mass; 2 : total internal mixture, add to mass; 3 : total internal mixture, replace mass. ↩

  15. Set fmoa=1 for Burrows et al. (2014) 27 parameterization; fmoa=2 for Gantt et al. (2011) 28 parameterization; fmoa=3 for simple parameterization based on Quinn et al., 2014; 29 fmoa=4 for Rinaldi et al. (JGR, 2013). 30 ↩

  16. iradsw > 0 interpreted as number of timesteps, iradsw < 0 interpreted as hours; iradsw = 0 disables shortwave radiation entirely ↩

  17. iradlw > 0 interpreted as number of timesteps, iradlw < 0 interpreted as hours; iradlw = 0 disables longwave radiation entirely ↩

  18. SW/LW radiation will be run continuously from the start of an initial or restart run ↩

  19. Calculates solar zenith angle averaged over a time step. In default model solar zenith angle is held constant over time. set by namelist_defaults_eam.xml for default physics. ↩

  20. Valid options are slingo or gammadist ↩

  21. Valid options are ebertcurry or mitchell ↩

  22. This sets cosp_ncolumns=10 and cosp_nradsteps=3 (appropriate for COSP statistics derived from seasonal averages), and runs MISR, ISCCP, MODIS, and CALIPSO lidar simulators (cosp_lmisr_sim=.true.,cosp_lisccp_sim=.true., cosp_lmodis_sim=.true.,cosp_llidar_sim=.true.). ↩

  23. use_od_ls should not be used at the same time with use_gw_oro. ↩

  24. Effective resolution of the grid for oGWD. Scales the magnitude of nonlinear oGWD. ↩

  25. Bulk drag coefficient. Scales the magnitude of FBD. ↩

  26. Effective resolution of the grid for sGWD.Scales the magnitude of sGWD. ↩

  27. S. M. Burrows, O. Ogunro, A. A. Frossard, L. M. Russell, P. J. Rasch, and S. M. Elliott. A physically based framework for modeling the organic fractionation of sea spray aerosol from bubble film Langmuir equilibria. Atmospheric Chemistry and Physics, 14(24):13601–13629, December 2014. URL: https://acp.copernicus.org/articles/14/13601/2014/ (visited on 2024-03-29), doi:10.5194/acp-14-13601-2014. ↩

  28. B. Gantt, N. Meskhidze, M. C. Facchini, M. Rinaldi, D. Ceburnis, and C. D. O'Dowd. Wind speed dependent size-resolved parameterization for the organic mass fraction of sea spray aerosol. Atmospheric Chemistry and Physics, 11(16):8777–8790, August 2011. URL: https://acp.copernicus.org/articles/11/8777/2011/acp-11-8777-2011.html (visited on 2024-04-25), doi:10.5194/acp-11-8777-2011. ↩

  29. Patricia K. Quinn, Timothy S. Bates, Kristen S. Schulz, D. J. Coffman, A. A. Frossard, L. M. Russell, W. C. Keene, and D. J. Kieber. Contribution of sea surface carbon pool to organic matter enrichment in sea spray aerosol. Nature Geoscience, 7(3):228–232, March 2014. URL: https://www.nature.com/articles/ngeo2092 (visited on 2024-04-25), doi:10.1038/ngeo2092. ↩

  30. Matteo Rinaldi, Sandro Fuzzi, Stefano Decesari, Salvatore Marullo, Rosalia Santoleri, Antonello Provenzale, Jost Von Hardenberg, Darius Ceburnis, Aditya Vaishya, Colin D. O'Dowd, and Maria Cristina Facchini. Is chlorophyll‐ \textit a the best surrogate for organic matter enrichment in submicron primary marine aerosol? Journal of Geophysical Research: Atmospheres, 118(10):4964–4973, May 2013. URL: https://agupubs.onlinelibrary.wiley.com/doi/10.1002/jgrd.50417 (visited on 2024-04-25), doi:10.1002/jgrd.50417. ↩