[RegCNET] Two questions about modelling dust in RegCM4

[Carolina D C Cavazos Guerra]

Hi,

I have used RegCM3 for dust modelling for the last couple of years so I
might say I have certain experience. This time I tried to do some
experiments using the newest RegCM4. I used the regcm.in.DUST included in
the examples folder as template to configure my regcm.in in the run folder
and used the same parameterization as in RegCM3. My first question comes
from the fact that the suggested values for the chem param in the regcm.in
for regcm4 is configured as follows:

 &chemparam
 idirect   =    2,
 inpchtrname  =   'DUST','DUST','DUST','DUST',
 inpchtrsol   =  0.10, 0.10, 0.10, 0.10
 inpchtrdpv  
=0.00000,0.00000,0.00000,0.00000,0.00000,0.00000,0.00000,0.00000,
 inpdustbsiz(:,1)  = 0.01, 1.00, 2.50, 5.00
 inpdustbsiz(:,2)= 1.00, 2.50, 5.00,20.00
 /

The parametres I have been using in regcm3 are:
chtrsol   =  0.50, 0.60, 0.70, 0.80,
 chtrdpv   = 0.00025,0.00050,0.00075,0.00100,0.00025,0.00050,0.00075,0.00100,
 dustbsiz  =  0.01, 1.00, 2.50, 5.00, 1.00, 2.50, 5.00,20.00,

As far as I remember the chtrsol and chtrdpv (inpchtrsol and inpchtrdpv in
regcm4) correspond to wet and dry deposition, so my question is: which
ones are the correct values?

My second query regards about outputs for a dust experiment. I did run an
experiment using the default values and everything appeared to be fine
until I started to analyse the resulting products. I noticed that the
parametres have still the same units as in regcm3 so I would expect if not
equal outputs values with similar magnitudes. What I notice is that all
values in certain parametres are unrealistically big (e.g. AOD eq 900)
whereas in other parametres such as emiss or colb, values have an order of
magnitude of around 10E2 or 10E3 bigger than in regcm3. So my question is,
am I doing something wrong with the configuration or is this related to a
bug in the dust emission scheme?

I would really appreciate any reply about these queries.

Regads

Carolina

><((((>`..`..`...><((((>`..`..`...><((((>
Carolina Cavazos Guerra
Department of Geography
University College London
Pearsons Building, Gower Street
London. WC1E 6bt, UK