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Seasonal Modeling of the Export of Pollutants from North America using the Multiscale Air Quality Simulation Platform (MAQSIP). Adel Hanna, 1 Rohit Mathur, 1 Carey Jang 2 and Joseph Pinto 2 1 Environmental Programs MCNC-North Carolina Supercomputing Center P.O. Box 12889
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Seasonal Modeling of the Export of Pollutants from North America using the Multiscale Air Quality Simulation Platform (MAQSIP) Adel Hanna,1 Rohit Mathur,1 Carey Jang2 and Joseph Pinto2 1 Environmental Programs MCNC-North Carolina Supercomputing Center P.O. Box 12889 Research Triangle Park, NC 27709-2889 USA 2 U. S. Environmental Protection Agency, USA
Outline • Objectives • The Multiscale Air Quality Simulation Platform (MAQSIP) • The SMRAQ Seasonal Simulation • Selected Meteorological cases during the summer of 1995 • Analysis of Flux of CO and O3 • Vertical Cross Sections of the Zonal Flux of CO and O3 • Summary
Objectives • Characterize possible meteorological patterns associated with the export of pollutants from North America during summer- 1995 case study • Characterize the vertical distribution of the export • Identify possible mechanisms associated with the export process
MAQSIP Structural Attributes Modular. Each process module acts on a common trace species concentration field while other variables are represented within each individual module Flexible. Alternate modules for process representation and/or numerical schemes; enables comprehensive module intercomparison; enables system to be customized to emulate other models Expandable. New modules can be added by users; allows system to improve as science evolves Multiscale. Multilevel nesting; adaptable to various scales and geographic regions (urban, regional, intercontinental) Generalized Coordinates. Different map projections; interface with different meteorological models (e.g., CMAQ/RAMS/MM5) A detailed description of MAQSIP can be found in (Mathur et al., 2001, and Odman et al., 1996,1998)
Seasonal Modeling for Regional Air Quality (SMRAQ) • Modeling over Eastern United States for the summer of 1995 (May 15 – September 11) • MAQSIP was run using horizontal resolution at 36 km and 22 sigma levels were used in the vertical (up to 100 mb ) • Meteorology was simulated by the MM5 exercised in a four dimensional data assimilation mode using analysis nudging and re-initialization every 5 days • The MM5 model was run in a nested mode covering a domain larger than the MAQSIP domain (108 km resolution in the coarse grid out side the MAQSIP 36 km domain) • Chemical Mechanism used in MAQSIP is the Carbon Bond Mechanism CB-IV) (version 4.2) • Emissions (anthropogenic and Biogenic) were processed using MCNC-SMOKE (Houyoux et al., 1999) • Time-invariant boundary concentrations were specified for this simulation: 35 ppb for O3 and 80 ppb for CO
Average 10 am – 5 pm model and observed O3. Comparisons between values in different percentiles (10- blue, 25 - magenta, 50 - green, 75 - yellow, 90 - red) for the entire simulation period The comparisons are at 137 locations at which observations are available (“rural” AIRS sites within the domain) (From: Kasibhatla and Chameides, Geophys., Res. Lett., Vol 27, 1415-1418, 2000) Comparisons with Surface O3 Observations
SMRAQ Applications Bias (model-observation) of the seasonal mean ozone concentrations derived from hourly concentrations Reference: Hogrefe et al. (2001)
Characterization of Synoptic Patterns • Southwest flow at the surface ahead of a cold front approaching the Northeastern US. (e.g., June 7-8 and 10-11, 1995) • A surface high pressure extending over the middle Atlantic and Northeastern US. An OMEGA pattern at 500 mb. Re-circulation over the Southeastern US (e.g. June 16-17-18, 1995) • A surface low pressure over central US June and OMEGA pattern at 500 mb (e.g. June 26 – 27, 1995) • Large-scale circulation with surface high pressure and 500 mb high pressure (e.g., July 14 and 15, 1995)
SUMMARY • The outflow from North America was characterized for a number of synoptic patterns • Over a season location (horizontal and vertical) and magnitude of transport can change on a daily basis • Future work • More detailed analysis of the time series of the outflow and quantification of export • Extend analysis to other species • Expand modeling domain eastward to capture the re-circulation cases and the export to Europe