Prescribed natural aerosol test

Test simulations

  • Experimental CAM-MPAS model within the CESM2.1 code
  • Compset: 2000_CAM50_CLM40%SP_CICE%PRES_DOCN%DOM_RTM_SGLC_SWAV
    • CAM5.4 physics
      • prescribed aerosol (probably those described in Bacmeister et al, 2014), no chemistry
        • Year 1850 aerosol input data (12 monthly values)
        • Applies random scaling on each day (a single number for all grid points)
    • CLM4 land model
    • MPASv4 dycore
    • ~120-km quasi-uniform global grid
    • Start from 1950-01-01 and run for one month

More details of the model configuration are provided below (atm_in)


Global, 3-hourly mean aerosol optical depths in year 1950

aod comparison

aod mode 1-2 comparison

aod mode 3 and macv2sp comparison

Global, 3-hourly mean aerosol burden and optical depths in January 1950

mode1 close-up comparison

mode2 close-up comparison

mode3 close-up comparison


1950-mean AOD spatial distributions

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

  • Not sure why optical depth is so much higher over Antarctica with prescribed aerosol


Spatial patterns of the high-frequency changes in aerosol optical depths

  • One-month long movies from 3-hourly output (1950-01)
  • Average through both day- and night-time hours for each 3-hour window

Total aerosol optical depth

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

Black Carbon

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

Dust

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

Sea Salt

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

Primary Organic Matter

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

Sulfate (SO4)

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

Secondary Organic Aerosol (SOA)

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

Anthropogenic aerosol optical depth from MACv2SP

1850-01

2000-01


Spatial patterns of the high-frequency changes in aerosol burdens

One-month long movies from 3-hourly output (1950-01)

Black Carbon

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

Dust

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

Sea Salt

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

Primary Organic Matter

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

Sulfate (SO4)

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation

Secondary Organic Aerosol (SOA)

Prescribed aerosol with random scaling

Prescribed aerosol without random scaling

MAM4 simulation


Build and run-time settings

- env_bld.xml

CAM_CONFIG_OPTS="-phys cam5.4 -chem none"


- atm_in

&prescribed_aero_nl
prescribed_aero_cycle_yr  = 1850
prescribed_aero_datapath  = '/global/cfs/cdirs/m1867/MPASinput/HighResMIP/atm/cam/chem/trop_mam'
prescribed_aero_file        = 'mam3_1.9x2.5_L30_1850clim_c130319.nc'
prescribed_aero_specifier       = 'num_c1', 'bc_c1', 'dst_c1', 'ncl_c1', 'pom_c1', 'so4_c1', 'soa_c1', 'num_c2',
        'ncl_c2', 'so4_c2', 'soa_c2', 'num_c3', 'dst_c3', 'ncl_c3', 'so4_c3', 'num_a1_logm',
        'bc_a1_logm', 'dst_a1_logm', 'ncl_a1_logm', 'pom_a1_logm', 'so4_a1_logm', 'soa_a1_logm', 'num_a2_logm', 'ncl_a2_logm',
        'so4_a2_logm', 'soa_a2_logm', 'num_a3_logm', 'dst_a3_logm', 'ncl_a3_logm', 'so4_a3_logm', 'num_a1_logv', 'bc_a1_logv',
        'dst_a1_logv', 'ncl_a1_logv', 'pom_a1_logv', 'so4_a1_logv', 'soa_a1_logv', 'num_a2_logv', 'ncl_a2_logv', 'so4_a2_logv',
        'soa_a2_logv', 'num_a3_logv', 'dst_a3_logv', 'ncl_a3_logv', 'so4_a3_logv'
prescribed_aero_type        = 'CYCLICAL’

&aerodep_flx_nl
aerodep_flx_cycle_yr        = 1850
aerodep_flx_datapath        = '/global/cfs/cdirs/m1867/MPASinput/HighResMIP/atm/cam/chem/trop_mam'
aerodep_flx_file        = 'mam3_1.9x2.5_L30_1850clim_c130319.nc'
aerodep_flx_specifier       = 'bc_a1DDF', 'bc_c1DDF', 'pom_a1DDF', 'pom_c1DDF', 'soa_a1DDF', 'soa_c1DDF', 'soa_a2DDF', 'soa_c2DDF',
        'dst_a1DDF', 'dst_c1DDF', 'dst_a3DDF', 'dst_c3DDF', 'bc_a1SFWET', 'bc_c1SFWET', 'pom_a1SFWET', 'pom_c1SFWET',
        'soa_a1SFWET', 'soa_c1SFWET', 'dst_a1SFWET', 'dst_c1SFWET', 'dst_a3SFWET', 'dst_c3SFWET'
aerodep_flx_type        = 'CYCLICAL'

&aerosol_nl
modal_accum_coarse_exch     = .true.

&prescribed_volcaero_nl
prescribed_volcaero_cycle_yr        = 2013
prescribed_volcaero_datapath        = '/global/cfs/cdirs/m1867/MPASinput/HighResMIP/atm/cam/volc'
prescribed_volcaero_file        = 'CCSM4_volcanic_1949115-21010115_with_10year_ramp_from_2015_to_2025_c20211012.nc'
prescribed_volcaero_type        = 'CYCLICAL'


Input files

- mam3_1.9x2.5_L30_1850clim_c130319.nc

netcdf mam3_1.9x2.5_L30_1850clim_c130319 {
dimensions:
time = UNLIMITED ; // (12 currently)
lat = 96 ;
lon = 144 ;
lev = 30 ;
ilev = 31 ;
slat = 95 ;
slon = 144 ;
nbnd = 2 ;
 
double time(time) ;
time:long_name = "time" ;
time:units = "days since 0000-01-01 00:00:00" ;
time:calendar = "noleap" ;
time:bounds = "time_bnds" ;

time = 675265.5, 675295, 675324.5, 675355, 675385.5, 675416, 675446.5,
    675477.5, 675508, 675538.5, 675569, 675599.5 ;

variables:

float bc_a1(time, lev, lat, lon) ;
    bc_a1:mdims = 1 ;
    bc_a1:units = "kg/kg" ;
    bc_a1:long_name = "bc_a1 concentration" ;
    bc_a1:cell_methods = "time: mean" ;
float bc_a1DDF(time, lat, lon) ;
    bc_a1DDF:units = "kg/m2/s" ;
    bc_a1DDF:long_name = "bc_a1 dry deposition flux at bottom (grav + turb)" ;
    bc_a1DDF:cell_methods = "time: mean" ;
float bc_a1SFWET(time, lat, lon) ;
    bc_a1SFWET:units = "kg/m2/s" ;
    bc_a1SFWET:long_name = "Wet deposition flux at surface" ;
    bc_a1SFWET:cell_methods = "time: mean" ;
float bc_a1_logm(time, lev, lat, lon) ;
    bc_a1_logm:mdims = 1 ;
    bc_a1_logm:units = "kg/kg" ;
    bc_a1_logm:long_name = "bc_a1 log concentration" ;
    bc_a1_logm:cell_methods = "time: mean" ;
float bc_a1_logv(time, lev, lat, lon) ;
    bc_a1_logv:mdims = 1 ;
    bc_a1_logv:units = "kg/kg" ;
    bc_a1_logv:long_name = " bc_a1 log^2 concentration" ;
    bc_a1_logv:cell_methods = "time: mean" ;

.....


- CCSM4_volcanic_1949115-21010115_with_10year_ramp_from_2015_to_2025_c20211012.nc

netcdf CCSM4_volcanic_1949115-21010115_with_10year_ramp_from_2015_to_2025_c20211012 {
dimensions:
    time = 1826 ;
    lev = 8 ;
    lat = 64 ;
 
float time(time) ;
    time:_FillValue = 1.e+36f ;
    time:axis = "T" ;
    time:long_name = "time" ;
    time:units = "days since 1949-01-01" ;
    time:calendar = "365_day" ;
    time:cell_methods = "time: mean" ;

time = 14, 45, 73, 104, 134, 165, 195, 226, 257, 287, 318, 348, 379, 410,
    438, 469, 499, ...

variables:
float lev(lev) ;
    lev:_FillValue = 1.e+36f ;
    lev:formula_terms = "none" ;
    lev:standard_name = "pure pressure levels" ;
    lev:units = "hPa" ;
    lev:long_name = "Pressure downwards" ;
    lev:bounds = "ilev" ;
double lat(lat) ;
    lat:_FillValue = 1.e+36 ;
double date(time) ;
    date:_FillValue = 1.e+36 ;
    date:units = "yyyymmdd" ;
    date:long_name = "Date" ;
double datesec(time) ;
    datesec:_FillValue = 1.e+36 ;
double MMRVOLC(time, lev, lat) ;
    MMRVOLC:_FillValue = 1.e+36 ;
    MMRVOLC:long_name = "layer volcanic aerosol mass mixing ratio" ;
    MMRVOLC:units = "kg kg-1" ;
float colmass(time, lat) ;
    colmass:_FillValue = 1.e+36f ;


Reference

Bacmeister, J. T., Wehner, M. F., Neale, R. B., Gettelman, A., Hannay, C., Lauritzen, P. H., et al. (2014). Exploratory high-resolution climate simulations using the Community Atmosphere Model (CAM). Journal of Climate, 27(9), 3073–3099. https://doi.org/10.1175/JCLI-D-13-00387.1

Stevens, B., Fiedler, S., Kinne, S., Peters, K., Rast, S., Müsse, J., et al. (2017). MACv2-SP: A parameterization of anthropogenic aerosol optical properties and an associated Twomey effect for use in CMIP6. Geoscientific Model Development, 10(1), 433–452. https://doi.org/10.5194/gmd-10-433-2017