Regional chEmical trAnsport Model(REAM)
Yuzhong Zhang, Yuhang Wang, Charles Smeltzer, Dasa Gu, Zhen Liu
1. REAM Modeling Setup and Specification2. Characterization of air pollution and emissions in China3. Pollutant distribution and lightning NOx study in USA4. Comparing with campaigns and monitoring5. HTAP2 preliminary results
REAM specification
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O3-NOx-VOCs-Halogen photochemistry
Dry/wet deposition
Meteorological fields
3-D advection
Emission inventory
BC: GEOS-Chem
Met: WRF
Biogenic: MEGAN
Vertical: 30 layers
Horizontal: 4km-36km
Biogenic emissions
Soil, lightning emissionsInitial, boundary condition
Vertical turbulent diffusion
Convective transport
REAM specification
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Dimension 0‐D 1‐D 3‐D
Resolution 4km 36km 200m*
Functionality CTM inversion
Cloud‐resolvingTracer model
REAM is a research model, providing flexibility and functionality for varied research objectives
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Study China air pollution
Liu et al., 2010; Liu et al., 2012
CARE Beijing 2007 campaign
0‐D 1‐D
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Height
Stability
Deep>1km
Medium0.5‐1km
Shallow<0.5km
Turbulent (<0.1K/km) 40 ‐ ‐Neutral (0.1‐1K/km) 123 24 ‐Stable (>1K/km) ‐ 7 12
Vertical distribution of pollutants
DISCOVER-AQ 2011 Baltimore
Zhang et al., in prep
1‐D
Inversed NOx emission trend in China
Gu et al., 2013; Gu et al., 2014Chemical nonlinearity
Increase of emissions overall
Decrease or flat emissions in the developed cities
3‐D
Inversion
Missing source of glyoxal using inversion
3‐D
Inversion
Missing glyoxal attributed to underestimation of aromatic emissions
Liu et al., 2012
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Lightning NOx emissions
Smeltzer et al., in prep
3‐D
Cloudresolving
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Trace NOx contributions from each grid
3‐D
Tagged‐Tracer
Each box has it's own NO2 tracer throughout the whole domain
• US domain• 36km• Gas phase• Base simulation
– Station surface– Station profile
• Fixed BC simulation
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HTAP status
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DISCOVER‐AQ vertical profiles
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DISCOVER‐AQ column correlations
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Observation Model Bias Correlation r MAD CV ppbv ppbv ppbv ppbv Whole 48.9 48.1 -0.8 0.66 7.0 14% SE US 48.5 50.7 2.2 0.73 5.9 12%
EPA monitoring sites
3‐D
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EPA monitoring sites
October, 2010
3‐D
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Ozonesonde in the western US
Monthly mean BC Hourly updating BC ozonesonde
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Calnex aircraft measurements
Questions?
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