A CHEMISTRY-TRANSPORT MODEL POST-PROCESSING TOOL FOR A FLEXIBLE CALCULATION OF AEROSOL

OPTICAL PROPERTIES

Gabriele Curci

CETEMPSDept. Physical and Chemical Sciences

University of L’Aquila

gabriele.curci@aquila.infn.it

9th International Symposium on Tropospheric Profiling, 3-7 September 2012, L’Aquila, Italy

τ(λ), ω(λ), g(λ), m(λ), dV/d log(r), …

CURRENT VERSION BASED ON GEOS-Chem OUTPUT

Bulk aerosol (mass only) chemistry-transport modelNeed to assign RH-dependent size distributions and species densities

ln r

dN /

d ln

r

rm

σg

Species 1

RH

Species 2

Species N . . .

If external mixing and spherical particles are

assumed:

Mie parameters averaged over size distributions may be pre-tabulated as a function of RH, and then used to calculate e.g. AOD at each time step and grid cell:

N

ii

ieffi

iext MRHr

RHQAOD

1 ,

,

)(

)(

4

3

INTERNAL MIXING OPTIONS

homogeneous mixing core/shell mixing

Species 1

Species 2

Species N . . .

Species combine in a new size distribution at each time step and grid cell

Distribution average Mie parameters are not useful anymore

Radius-by-radius calculations using Mie parameters tabulated as a function of size and refractive index(CPU time x 10 w.r.t. external mixing)

MISR SPECTRAL AODCONSTRAINT ON MASS AND SIZE DISTRIBUTION

443 nm 865 nm

MISR

GEOS-Chem

GC-

MISR

MISR SPECTRAL AODCONSTRAINT ON MASS AND SIZE DISTRIBUTION

443 nm 865 nm

MISR

GEOS-Chem

GC-

MISR

AERONET EFFECTIVE RADIUSCONSTRAINT ON SIZE DISTRIBUTION

AERONET VOLUME CONCENTRATIONCONSTRAINT ON SIZE DISTRIBUTION AND MASS

AERONET REFRACTIVE INDEX (REAL)CONSTRAINT ON COMPOSITION

AERONET REFRACTIVE INDEX (IMAGINARY)CONSTRAINT ON COMPOSITION

10^

AERONET SINGLE SCATTERING ALBEDOCONSTRAINT ON MIXING

EXTERNAL MIXING

CORE/SHELL MIXING

INPUT TO RADIATIVE TRANSFER MODEL (LIBRADTRAN)

FUTURE DEVELOPMENTS

• Complete debugging and release version with internal mixing option and AERONET-like output

• Extension to sectional and modal aerosol models

• Definition of a general input format. Also useful to input idealized profiles

• Continued implementation of more flexible input/output options

CONCLUDING REMARKS

IN DEVELOPMENT!IF INTERESTED IN FlexAOD …

JUST LET ME KNOW!

gabriele.curci@aquila.infn.it