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Global/Regional/Urban Multiscale Study. What is the Uncertainty Caused by IC/BCs in the Regional/Urban Ozone Simulations? Linking CMAQ with GEOS-CHEM. Nan-Kyoung Moon and Daewon Byun Institute for Multidimensional Air Quality Studies (IMAQS) University of Houston Rokjin Park and Daniel Jacob
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Global/Regional/Urban Multiscale Study What is the Uncertainty Caused by IC/BCs in the Regional/Urban Ozone Simulations? Linking CMAQ with GEOS-CHEM Nan-Kyoung Moon and Daewon Byun Institute for Multidimensional Air Quality Studies (IMAQS) University of Houston Rokjin Park and Daniel Jacob Harvard University
Regional air quality modeling requires prescription of IC/BCs • - Current usage; mostly rely on “climatological” fixed profiles • - Could be different at each side of domain reflecting certain regional differences • - Work best when outside the boundary of the domain does not have much direct emissions and no high concentration blobs already existing • - Need to study sensitivity of the model simulations to the different IC/BCs • - In reality fixed profiles are never accurate!
Even with ozonesonde or other measurements…. • - Intermittent data in space and time • -Mostly ozone is the only parameter available • - There are many other important photochemical precursor species that must be prescribed • - The intra-relations among the species must be consistent • - Need a systematic IC/BC methods that can address above problems • - Let’s try to link global tropospheric model results with regional air quality model
First Look 4.0 Late Look 4.0 Conventional Final Dump - NCEP Conventional CDAS Dump - NCEP SSM/I (TPW only) Wentz SSM/I (TPW only) Operational Sea Ice Operational Sea Ice Interactive TOVS retrievals Interactive TOVS retrievals QuickSCAT QuickSCAT SBUV Ozone SBUV Ozone SST - Downstream Average Reynolds SST - Centered Average ---- GADS (Passive) Harvard GEOS-CHEM model This is a global 3-D model of atmospheric chemistry driven by assimilated meteorological observations from the Goddard Earth Observing System (GEOS) of the NASA Data Assimilation Office (DAO). It is being developed by groups at Harvard, Duke, NASA/GSFC, U. Washington, Rutgers U., JPL, EPFL/Lausanne, CNRS/Toulouse, and the University of L'Aquila, Italy, as a versatile tool for application to a wide range of atmospheric chemistry problems. NASA GEOS DAO Products
Air Quality Modeling with US EPA’s Models-3 CMAQ Community Multi-pollutant Multi-scale Air Quality Modeling System
To link GEOS_CHEM with EPA’s CMAQ …… First, Horizontal & Vertical Interpolations needed GEOS-CHEM (Goddard Earth Observing System-CHEMisrty) MODEL3 CMAQ(Community Multi-scale/pollutant Air Quality model) LAMBERT CONFORMAL 108 km X 108 km 23 layers in Sigma Z (Po) LAT-LON 2 degree X 2.5 degree 20 layers in Sigma P Initial & Boundary Condition in IO/API Format in 108km resolution
Second, develop procedures matching GEOSCHEM and CMAQ chemistry mechanism GEOS-CHEM O3-NOX-Hydrocarbon chemistry : 24 species CMAQ CB4 : 16 species CB-4 example Un-used species : ACET
LAT-LON 2O X 2.5O w/ GEOSCHEM vertical coordinate Chemistry Mapping CB4 & SAPRC GEOS2CMAQ LAMBERT CONFORMAL w/ 108 km I/OAPI on CMAQ/MM5 vertical coordinate IC/BC for CMAQ resolution The diagram of linkage between GEOSCHEM and CAMQ IC/BC Process
Issues in linking GEOSCHEM and CMAQ (1) • Possible inconsistencies between the global and regional scale dynamics • - inflow conditions at the boundary • - differences in the evolution of dynamics with time • Remedy (yet to be tested) • Run regional scale model with global scale output as input for initialization and analysis nudging • cf: Currently most uses EDAS as basic input for MM5
Comparison of Wind Fields Let’s see how big the problem is: GEOSCHEM ; DAO GEOSCHEN : W -NWesterly (inflow) MM5 : Northerly (parallel to grid)
GEOSCHEM ; DAO
GEOSCHEM : Easterly and northerly MM5 : Clock wise rotation motion
GEOSCHEM : inflow MM5 : outflow
Issues of linking GEOSCHEM and CMAQ (2) • Chemistry Issues: • - coarse resolution concentration distribution in global scale move into fine scale regional grid • - differences in the evolution of concentration patterns with time • - different chemical mechanism representation • - different representation of atmospheric reactivity in the coarse scale • Remedy • - use as much consistent chemistry mechanisms (TBD)
(yet to be simulated) GEOS-CHEM Mapping Table CMAQ SAPRAC-99
Horizontal distribution of O3 concentration from GEOS-CHEM global output at Layer 1 2 X 2.5 degree resolution 108km resolution
Horizontal distribution of CO concentration from GEOS-CHEM global output at Layer 1 2 X 2.5 degree resolution 108km resolution
Comparative Study with CMAQ 1. GEOSCHEM vs. CMAQ CONUS 2. CMAQ CONUS vs. CMAQ Regional 36-km 3. Effects of using different IC/BCs - profile vs. GEOS-CHEM for CONUS domain
The comparison of vertical cross section between GEOSCHEM and CONUS results GEOSCHEM 108km CONUS 36km
August 16, 2000 (First day of simulation) September 1, 2000 (Last day of simulation) O3.. August 16, 2000, 00UTC (First day of simulation) GEOSCHEM CONUS
September 1, 2000. 09 & 21UTC GEOSCHEM CONUS
CO.. August 16, 2000, 00UTC GEOSCHEM CONUS
September 1, 2000. 09 & 21UTC GEOSCHEM CONUS
NO2.. August 16, 2000, 00UTC GEOSCHEM CONUS
September 1, 2000. 09 & 21UTC GEOSCHEM CONUS
The comparison of vertical cross section for O3, CO, FORM and NO2 between Regional vs CONUS 36-km CMAQ results. ICBC from GEOSCHEM 108km data
Comparison of horizontal distribution between CONUS and Regional 36km O3, August 31, 2000. 09 & 21 UTC
The comparison of vertical cross section between CONUS and regional domain results CONUS 36km Regional 36km
August 31, 2000. 09 & 21UTC C O N U S Regional 36km
August 31, 2000. 09 & 21UTC C O N U S Regional 36km
The comparison for O3, CO and NO2 between profile IC/BC vs. IC/BC from GEOSCHEM 108km data
The comparison of CMAQ results in different IC and BC (2000.08.25. 09, 21UTC) 03AM CST 03PM CST Profile Data Case GEOS-CHEM Data Case
08/28/2000 03AM CST 09AM CST 12:00 CST 03PM CST
Continued, now at 4-km resolution (August, 26, 2000, 21UTC) Profile Data Case GEOS-CHEM Data Case
Conclusive Remarks • Issues related with linking global tropospheric chemistry model with regional air quality model has been studied • Problems with current fixed profile method identified • Global tropospheric model provides needed dynamic evolution and concentration distribution realism not existing in profile method • We observe significant changes in the atmospheric reactivity conditions depending on profile vs. GEOSCHEM IC/BC • Global-regional scale linking is the best when outside the regional domain boundary does not have much direct emission sources; e.g., CONUS domain • Need to study the issues of harmonization of chemical mechanisms further • Need to quantify and minimize the effects of different dynamics between the global and regional meteorological data used