Recent Advances in the Use of Chemical Transport Models in Atmospheric Chemistry Studies Greg Carmichael, University of Iowa

Models are an Integral Part of Atmospheric Chemistry Studies Flight planning Provide 4-Dimensional context of the observations Facilitate the integration of the different measurement platforms Evaluate processes (e.g., role of biomass burning, heterogeneous chemistry….) Evaluate emission estimates (bottom-up as well as top-down) New comprehensive data sets to test/evaluate models

TRACE-P/Ace-Asia EXECUTION Emissions -Fossil fuel -Biomass burning -Biosphere, dust Long-range transport from Europe, N. America, Africa ASIA PACIFIC Satellite data in near-real time: MOPITT TOMS SEAWIFS AVHRR LIS 3D chemical model forecasts: - x - GEOS-CHyEM - CFORS - z FLIGHT PLANNING Boundary layer chemical/aerosol processing ASIAN OUTFLOW Stratospheric intrusions PACIFIC

DC8P3  Two aircrafts – DC8 and P3 urban plumes  Chemical evolution during continental outflow, biomass burning, dust outbreaks, and urban plumes  22  22 flights out of Hong Kong, Okinawa and Tokyo  O 3, CO, SOx, NOx, HOx, RH and J  100m to 12000m China NASA GTE TRACE-P Mar’01- Apr’01

CFORS/STEM-2K1 Model Data Flow Chart Large-scale Meteorological Fields (JMA, NCEP, ECMWF CFORS/RAMS STEM-2K1 On-Line TUV wind velocities, temperature, pressure, water vapor content, cloud water content, rain water content and PV etc. Dust, Sea Salt, Lightning NO x Biogenic Emisisons Emission Preprocessor Biomass Emissions Volcanic SO 2 Emissions Anthropogenic Area Emissions Fuel/activity info Large Point Sources Satellite Observations (fire counts, ozone columns, sea surface temperature, etc.) Forecasts Or Post Analysis Tracers/Markers: SO2/SulfateDMS BCOC VolcanicMegacities CO fossilCO-Biomass EthaneEthene Sea SaltRadon Lightning NOx Dust 12 size bins

Ace-Asia & Trace-P Focused on Asian Outflow March 2, 2001 March 7, 2001 March 6, 2001 March 5, 2001 March 4, 2001 March 3, 2001 March 10, 2001 March 9, 2001 March 8, 2001

Fight Planning: Frontal outflow of biomass burning plumes E of Hong Kong Observed CO –Sacshe et al. Observed aerosol potassium - Weber et al. Biomass burning CO forecast Longitude 100 ppb

P-3B SO2 How Well Do Models Capture the Observed Features?

Predictability – as Measured by Correlation Coefficient Met Parameters are Best Performance decreases with altitude

06GMT, April 07, GMT, April 11, 2001 Ace Asia – Focus on Aerosols

April 9 April 12 Asian Outflow: Complex Mixture of Dust, Bio, and Fossil Components Data: Sugimoto, et al. Poster: A11A0060 Sataka et al.

Ron Brown observed high AOD in Japan Sea Takla makan Gobi Log10(Dust) AOD Observed Al and model dust Lidar Ext. Of Ron Brown = 0.2/km This may be Miyakejima sulfate Plate 2 Data: Bates et al.

How Is Photochemistry Impacted By These Aerosols? 1) Photolysis Impacts

Surface reflection Ice cloud Water cloud EP/TOMS Total Ozone (Dobson) Dust Black Carbon Organic Carbon Sulfate Other PM2.5 and Other PM10 Sea Salt absorption by gas-phase species O 3, SO 2 and NO 2 Inputs from STEM 3-D field STEM TOP 15km O 3 (Dobson) below STEM top height TUV TOP 80km Overtop O 3 = Output: 30 kinds of J-values for SAPRC99 mechanism Framework for Analyzing Chemistry/Aerosol Interactions: Model (STEM+TUV) + Laboratory Studies + Field Experiment Heterogeneous rxns on dust for NO x, O 3, SO 2, HNO 3

Cloud Top Temperature (°C) Flight Altitude (m) A example: TRACE-P flights on March 27 DC-8 #15 P-3 #17 P-3 flight #17: volcanic plume observation DC-8 flight #15: frontal study DC-8 J[NO 2 ] P-3 J[NO 2 ]

How is Photochemistry Impacted By These Aerosols? 1) Photolysis Impacts

How is Photochemistry Impacted By These Aerosols? 2) Heterogeneous Rxns:Direct Ozone Loss? Dust BC Sulfate

Lessons Learned Asian outflow is complex, characterizing it requires 4-dimensional measurements. Impacts on chemistry and radiation appear to be important. Closer integration of emissions, models and measurements is necessary to better quantify our understanding of Asian aerosols.

Through a NSF ITR Grant we are developing data assimilation tools – we have a 3-d version ready for application

We are Developing General Software Tools to Facilitate the Close Integration of Measurements and Models The framework will provide tools for: 1) construction of the adjoint model; 2) handling large datasets; 3) checkpointing support; 4) optimization; 5) analysis of results; 6) remote access to data and computational resources.

Advantage Of Adjoints Is That We Get Sensitivities; e.g., Influence Functions (top view) ( top:Mar.1-3, bottom:Mar.22-24; from left to right: O 3, NO 2, HCHO)

Target Applications Air quality forecasting in urban environments; Integration of measurements and models to produce a consistent/optimal analysis data set for atmospheric chemistry field experiments (e.g., Ace-Asia); Inverse analysis to produce a better estimate of emissions; Design of observation strategies to improve chemical forecasting capabilities. Chemical Weather Forecasting Satellite Products Global Assimilation Regional Prediction Public Impact Requires Close Integration of Observations and Models

Ability of forecast models to represent the individual processes controlling air pollution formation and transport. & intercontinental regional Application: The Design of Better Observation Strategies to Improve Chemical Forecasting Capabilities. Data Assimilation Will help us Better Determine Where and When to Fly and How to More Effectively Deploy our Resources (People, Platforms, $$s) We Plan to Test These Tools Including Adaptive Measurements in the Summer of 2004

U. Iowa/Kyushu/Argonne/GFDL With support from NSF, NASA (ACMAP,GTE), NOAA, DOE