Environmental Engineering Reference
In-Depth Information
WRF
MM5
WRF,5Lsoil,MRF
Fig. 2.
Monthly mean PM10 concentrations for January by CHIMERE using the MM5
meteorology (a), WRF meteorology (b) and WRF meteorology using the five-layer soil tempe-
rature model + MRF PBL scheme (c)
4. Conclusions
The difference in PM10 concentrations for January between CHIMERE/MM5 and
CHIMERE/WRF is around a factor 1.6 (PM10 higher for CHIMERE/MM5). This
difference and the larger underestimation in PM10 concentrations by CHIMERE/
WRF are related to the differences in heat fluxes and the resulting PBL heights
calculated by WRF. In general the PBL height by WRF meteorology is a factor
2.8 higher at noon in January than calculated by MM5, which affect the vertical
mixing of the aerosols. Changing the Noah LSM scheme in our WRF pre-processing
for the 5-layer soil temperature model, calculated PM10 concentrations for January
2005 increase by 30% with respect to the simulation using Noah LSM. This study
also showed that the difference in microphysics scheme has an impact on the
profile of cloud liquid water (CLW) calculated by the meteorological driver and
therefore on the production and removal of SO
4
=
aerosol. For June the differences
in PM10 (and O
3
) concentrations between the model simulations using MM5 and
WRF are small.
References
Bessagnet, B., Hodzic, A., Vautard, R., Beekman, M., Cheinet, S., Honeré, C., Liousse, C.,
Rouil, L., Aerosol modeling with CHIMERE - preliminary evaluation at the continental
scale, Atmos. Environ., 38, 2004.
