Environmental Engineering Reference
In-Depth Information
5.3 Cloud Processing of Gases and Particles in Urban-
Industrial Plumes: Comparison of Several Models
W. Gong
1
, J. Zhang
1
, S.-W. Kim
2
, M. Leriche
3
, G. Frost
2
, G.A. Grell
2
,
C. Mari
3
, S. McKeen
2
, J.-P. Pinty
3
, P. Tulet
4
, A.M. Macdonald
1
,
1
and W.R. Leaitch
1
Science and Technology Branch, Environment Canada, Downsview, ON, Canada
2
NOAA/ESRL & CIRES, University of Colorado, Boulder, CO, USA
3
LA/CNRS, Université Paul Sabatier, Toulouse, France
4
CNRM/GAME, Météo-France, Toulouse, France; also at LACy, Université de la Réunion,
La Réunion, France
Abstract
Several regional/meso-scale chemical transport models are applied to a
case study of cloud processing of urban-industrial plumes. The study case is based
on airborne measurements made in and below stratocumulus downwind of Chicago
during the ICARTT field campaign in summer 2004. Model simulations of cloud
microphysics, trace gases and aerosol particle concentrations are compared with
aircraft observations.
1. Introduction
Clouds play an important role in the processing and cycling of chemicals in the
atmosphere. Modeling the effects is challenging due to the temporal and spatial
scales and the variety of processes and clouds. As part of the Seventh World
Meteorological Organization (WMO) International Cloud Modeling Workshop
(Morrison et al., 2009), three regional/meso-scale models (WRF-CHEM of
NOAA/Environmental Science Research Laboratory, MesoNH of Laboratoire
d'Aerologie/Centre National de la Recherche Scientifique, and AURAMS of
Environment Canada) are applied to simulate a case of cloud processing of urban-
industrial plumes downwind Chicago. On August 10, 2004, during ICARTT
(Fehsenfeld et al., 2007), the National Research Council of Canada Convair 580
sampled in and below cumulus and stratocumulus clouds over Michigan ahead of
an advancing cold front. The sampling (including trace gases, aerosol physics and
chemistry, and cloud microphysics and chemistry: Hayden et al., 2008) was
conducted along two north-south lines: one ca. 200 km east of Chicago (~86 W)
and a second ca. 200 km further east (~84 W). Multiple plumes from the Chicago
area were encountered across the aircraft sampling lines both in and below cloud.
The observations indicate chemical processing by the clouds.
