Hodzic Roux, Alma, David Gochis, National Center for
Atmospheric Research
The scientiÞc
understanding of the formation and aging of organic aerosols in forest
environments is still limited. The Bio-hydro-atmosphere interactions of Energy,
Aerosols, Carbon, H2O, Organics and Nitrogen (BEACHON)-RoMBAS intensive aerosol
study took place from 25 July to 25 August 2011 at the Manitou Observatory
Forest in Colorado with the speciÞc objective of characterizing the formation
of biogenic particles in the forest canopy, and quantifying the perturbations
that occur in presence of anthropogenic emissions. Here we present the results
of the high-resolution simulations (4km) that were performed over the Colorado
mountains using the WRF-Chem model during summer 2011. The aerosols were
simulated using the MOSAIC aerosol model with updated SOA yields and NO3
chemistry. The meteorological and passive tracer analyses were performed to
identify the main circulation patterns and periods featuring the transport of
the front-range urban pollution over the forest site. For each of these periods
the WRF-Chem model predictions of main organic aerosol components were assessed
and compared with the AMS data. The role of NOx in SOA formation is discussed.
In addition, the sensitivity of the model results to changes in the landuse
were assessed by comparing the results between MODIS and USGS landuse types.