Transcript What’s new in CAM-chem JEAN-FRANÇOIS LAMARQUE ANDREW CONLEY FRANCIS VITT PRESENTING THE WORK OF MANY OTHERS.

What’s new in CAM-chem
JEAN-FRANÇOIS LAMARQUE
ANDREW CONLEY
FRANCIS VITT
PRESENTING THE WORK OF MANY OTHERS
Coupling with CLM
• Interactive VOC emissions in CLM - in separate
svn branch (updated to MEGAN)
• VOC fluxes are communicated to CAM via the
Model Coupling Toolkit (MCT)
• Dry deposition in CLM - in separate svn branch
1. Dry deposition velocity of chemical species
computed in CLM are communicated to CAM
via MCT
2. Namelist drydep_inparm added to drv_in
which read by both CLM and CAM. This list
the species which have deposition
Aerosols packages
• trop_mozart_aero
prognostic chemistry, carbon aerosols, dust
and sea salt sulfate
• trop_mozart_prescribed_aero
prescribed aerosols
• trop_mozart_ghg_paero
prognostic greenhouse gases
prescribed aerosols
• Extended secondary-organic aerosol representation
Flexible aerosol package definition
• More flexible aerosol package (prognostic and
prescribed)
- generates a chemistry mechanism file
automatically
- invokes chemistry preprocessor from CAM
configure utility
- user specifies desired prognostic and
prescribed species via configure options
-prog_species SO4,DST,SSLT,OC,BC,GHG,CARBON16
-data_species O3,H2O2
• To be extended to generalize way of handling
building chemistry mechanisms
Flexible photolysis mapping
 Specify photolysis mapping at the level of the input
file
 Forces correct mapping of required photolysis from
LUT/FAST-TUV; also enables a much smaller
memory footprint of the LUT (only in WACCM at
this point but transition to CAM underway)
CAM/WACCM merger
 Ultimate goal is to have a single model branch
 Will enable mix/match at either build- or run-time
 Will include merging chemistry mechanisms and
WACCM-specific physics/chemistry subroutines
(extend user-defined reaction rates)
Radiative interface and namelist definition
 Goal is to streamline definition of radiatively-active
species and associated radiative properties (bring it
to namelist/user-level)
 Enable the use of other aerosol packages than massbased
 Allow for easy and flexible radiative forcing
calculations
Radiative Constituents
User Interface, Development
ANDREW CONLEY
BILL COLLINS, BRIAN EATON, JEAN FRANCOIS LAMARQUE,
PHIL RASCH, FRANCIS VITT
FEBRUARY 11, 2008
CCWG
BOULDER, CO
Namelist
rad_climate='D_N2O:N2O',
'D_CH4:CH4',
...
'P_O3:O3',
'P_Q:H2O',
'D_dust1:/fullpath/dst1.nc',
...
Raddiag_1='D_N2O:N2O',
'D_CH4:CH4',
…
‘D_O3:O3',
'P_Q:H2O',
'P_dust1:/fullpath/dst1.nc',
...
CAM or Offline Driver
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Distribution and mmr of gasses
Distribution, mmr, composition, and
microphysical state of aerosols
Thermodynamic state of atmosphere
Composition and microphysics of clouds (liquid,
cloud, number distribution, shape
characteristics)
Subgrid cloud characterization (cldfrc,
maxrandom overlap)
Solar and surface characteristics
Radiation (SW and LW)
 Computes RT through the composition specified
using the optics specified
 Returns heating rates and fluxes to CAM
 Does not compute microphysics (such as
hygroscopic growth or crystal shape)
 May (eventually) compute photolysis.
Why?
 Test alternative representations.
 Test different optical characterizations.
 Clarify functions of code base.
Example: bc.nc
 Sw_ext (sw_band)
 Sw_ssa (sw_band)
 Sw_asm (sw_band)
 Lw_ext (lw_band)
 Opticstype #method
Status
 Roundoff level changes on Linux/lf95/mpi -
untested elsewhere.
 Need to develop optics for expected aerosols and
expected RT method.
The Future?
 Internally mixed aerosols
 Real-time Mie calculation (initialization?)
 Offline driver for radiation.
 Separate microphysical specification from optical
characterization.