View source for Brief summary of GLOMAP-mode: global size-resolved aerosol microphysics

The UKCA aerosol scheme is a simplified version of the GLobal Model of Aerosol
Processes (GLOMAP) (e.g. Spracklen et al., 2005). GLOMAP is designed to
simulate the aerosol particle size distribution and represents the
key microphysical processes (nucleation, coagulation, condensation
and cloud processing) which control it.

The simpler GLOMAP version used in
UKCA, called GLOMAP-mode, simulates these processes within a two-moment
modal aerosol dynamics approach (number and mass in each mode), which requires
much fewer transported tracers (typically 15 to 30) than the original
bin-resolved GLOMAP scheme which requires 100-200 transported tracers
for a multi-component simulation (e.g. Spracklen et al, 2008).

The dynamically evolving particle size distribution in UKCA
leads to improved simulation of the number concentration of
the sub-set of particles that interact with the clouds (cloud
condensation nuclei, or CCN).

The incorporation of the UKCA aerosol in HadGEM3 will represent
a step-change in the capability of the UK climate model to
simulated aerosol indirect effects on climate.

A recent publication in Geoscientific Model Development (Mann et al, 2010)
describes GLOMAP-mode in detail and presents evaluation of the model
in the chemical transport model against a wide range of observations.

References:

Spracklen, D. V., Pringle, K. J., Carslaw, K. S., et al.:
A global off-line model of size-resolved aerosol microphysics:
I. Model development and prediction of aerosol properties,
Atmos. Chem. Phys., 5, 2227--2252, doi:10.5194/acp-5-2227-2005, 2005.

Spracklen, D. V., Carslaw, K. S., Kulmala, M., et al.:
Contribution of particle formation to global cloud condensation
nuclei concentrations,
Geophys. Res. Lett., 35, L06808, doi:10.1029/2007GL033038, 2008.

Mann, G. W., Carslaw, K. S., Spracklen, D. V., et al.:
Description and evaluation of GLOMAP-mode: a modal global aerosol
microphysics model for the UKCA composition-climate model.
Geosci. Model Dev., 3, 519-551, 2010.

For more details about the GLOMAP-mode aerosol scheme and the
interface to the rest of UKCA and other parts of the UM, 
please contact Graham Mann (NCAS, University of Leeds)
gmann@env.leeds.ac.uk.