Progress 01/01/08 to 12/31/12
Outputs
OUTPUTS: (1) CMAQ model improvements include (a) addition of 22 gaseous reactions of NH3, H2S, CH4, and N2O, (b) addition of 11 nucleation modules, (c) improved treatment of bidirectional exchanges of NH3, (d) improved aerosol thermodynamic equilibrium, and (e) coarse PM emissions and heterogeneous chemistry. The original and improved CMAQ were applied at various spatial scales (1.33, 4, 12, and 36-km) over the U.S. for current and future years with different emission scenarios and under future climate conditions. (2) Comparison of 3 aerosol thermodynamic modules produced 1 paper (paper 16) (3) Comparison of 5 box models with different treatments for NH3 fluxes and evaluation using observations produced 1 paper (paper 14) (4) MM5/CMAQ runs with process analysis at 4-km were conducted for 2002, 2009, and 2018 over NC. The results produced 3 papers, 2 in Atmos. Environ. and 1 in Atmos. and Climate Sci. (Papers 1, 2, and 11) (5) MM5/CMAQ results with 11 nucleation modules produced 2 papers in J. of Geophys. Res. (Papers 3 and 4) (6) MM5/CMAQ and MM5/CAMx simulations and process analysis at 4- and 1.33-km were performed for 2002 and 2018 over southeastern U.S. to study the role of total reduced nitrogen in PM2.5 and the impact of grid resolution on model results. Sensitivity runs were conducted with 4 emission control scenarios: 50% reductions in emissions of agricultural-livestock (AL) NH3, NOx, and SO2, one at one time, and in emissions of all 3 species in one simulation to evaluate the effectiveness of emission control scenarios in controlling PM2.5. 2018 results were used to study the role of NH3 emissions in PM2.5 with projected reductions of NOx and SO2. These results produced 3 papers, 2 in Aero. and Air Quality Res. and 1 in Atmos. Environ. (papers 8, 9, and 10). (7) Source appointment was performed using CMAQ and CAMx at 12-km for 2002 over eastern U.S. to study the contributions of 10 sources including agricultural emissions to PM2.5. Additional sensitivity runs were performed to evaluate the importance of inline dry deposition calculation, gas-phase reactions of NH3 and H2S, emissions of H2S, and bidirectional exchange of NH3, and the model sensitivity to various parameters used in bidirectional exchange treatments. These results produced 2 papers, 1 in Atmos. Pollu. Res., 2 in preparation (papers 5, 12, and 13). (8) CMAQ simulations were performed for 2002 at 36- and 12-km resolutions over the continental U.S. to evaluate the annual long-term trends of air pollutants. These results produced 1 paper in Atmos. and Climate Sci. (paper 6). (9) CMAQ simulations with an online dust module and heterogeneous chemistry were performed. These results produced 1 paper in Atmos. Chem. and Phys. (paper 7). (10) The latest version of CMAQ (v. 5.0) with advanced bidirectional NH3 exchange treatments was performed at 36-km over the U.S. for 2001-2005, 2026-2030, and 2046-2050 to evaluate multiple-year trends of multiple pollutants and nitrogen deposition under current and future climate and emission scenarios. These results produced 2 papers (papers 15 and 17). (11)Results were disseminated at conferences/workshops, universities/organizations, and journals. PARTICIPANTS: Dr. Yang Zhang, Project Director, NCSU, managed the project, conducting nucleation module intercomparison, advised students on model development, application, and evaluation tasks. Dr. Wayne Robarge, co-PD, NCSU, provided measurement data for model validation and review conference presentations, and served on student thesis committee. Dr. John Walker, co-PD, the U.S. EPA, provided measurement data for model validation and review conference presentations, and served on student thesis committee. Mr. Kai Wang, PhD student during Jan. 1, 2008- Sept. 14, 2011 and post-D during Sept. 15-Dec. 31, 2012, NCSU, conducted MM5/CMAQ simulations at 12-km and examined the impact of bidirectional exchange of NH3 on air quality and deposition fluxes using box and 3-D models. Dr. Ming-Tung Chuang, post-D, NCSU, conducted literature survey and initial module setup for NH3 dry deposition testing. Mr. Wei Wang, conducted source apportionment using emissions based on the 2005 U.S. EPA National Emissions Inventory, and assisted in the installation of the model evaluation tool and post-processing results. Ms. Ashley Penrod, conducted WRF/CMAQ simulations at 36-km for 2001-2005, 2026-2030, and 2046-2050 to study the impact of climate change on future air quality. Ms. Kristen Olsen, performed baseline MM5, CMAQ, and CAMx model application and evaluation at 4- and 1.33 km and sensitivity simulations under various emission reduction scenarios for Jan. and Jul 2002. Mr. Xinyi Dong, improved gas-phase chemistry involving NH3 and H2S of MM5/CMAQ. Mr. Mike Burr, conducted source apportionment simulations using CMAQ/BFM and CAMx/PSAT using emissions based on the 2002 U.S. EPA National Emissions Inventory Ms. Xiaohuan Liu, performed baseline MM5, CMAQ, and CAMx model application and evaluation at 4-km for Apr, Aug., and Oct. 2002 and CMAQ simulations for Jan., Apr, Aug., and Oct. 2018; aerosol thermodynamic module intercomparison; process analysis for Jan., Apr, Aug., and Oct. 2002. Collaborators: Dr. Dan Loughlin, U.S. EPA, provided projected region-specific emission growth factors over U.S. for future year simulations, and served on the student thesis committee Dr. Ruby Leung, Pacific Northwest National laboratory, provided CCSM post-processed files to initialize WRF simulations Dr. David Streets, Argonne national laboratory, provided projected uniform emission growth factors over U.S. for future year simulations Dr. Jonathan Pleim, the U.S. EPA, provided a bidirectional exchange of NH3 parameterization implemented in CMAQ for box model study. Dr. Yi-Wua Wu, the NWS/NCEP/NOAA, provided a multi-layer canopy resistance model of bi-directional NH3 exchange for box model study. Ms. Shiang-Yuh Wu, Department of Air Quality & Environmental Management, Clark County, NV, assisted in emission processing, initial and boundary conditions for WRF, model evaluation tool, and post-processed results. This project provides training and professional development for several graduate students and post-doctoral fellows to conduct research tasks and present their results at national/international conferences. TARGET AUDIENCES: Students (undergraduate and graduate), post-D research fellows, researchers in scientific community, external organizations and stakeholder groups including the NCDAQ, the NC Pork Council, the National Pork Board, River Keepers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
1. As SO2 and NOx emissions decrease, NH3 will play a more important role in PM2.5 formation. Current models have limited capabilities in capturing observed NH3 fluxes and concentrations, due to uncertainties in emissions, the reaction of agricultural pollutants, and land use data and deficiencies in the 1-layer bi-directional exchange scheme. These results indicate urgent needs to improve NH3 emissions and bidirectional exchange model and to validate and improve the model with observations for NH3 emissions, concentrations, deposition fluxes. Addressing these limitations should be the top research priorities in improving the current model capability in simulating the fate and transport of agricultural pollutants. 2. CMAQ/CAMx runs at 1.33- and 4-km performed well for O3 and NH3 to NH4+ conversion but showed large inaccuracies in reproducing levels of NH3 and PM2.5, and dry/wet deposition. 3. NH3 plays an important role in PM2.5, but current emission control strategies focus only on SO2 and NOx in southeastern U.S. The largest reductions of PM2.5 are by up to 19.2% in January and 18.3% in July when emissions of SO2, NOx, agricultural livestock-NH3 (AL-NH3) are reduced by 50%. AL-NH3 reductions result in the largest decrease in January by up to 16%. Reducing AL-NH3 emissions together with the SO2 and NOx control reduce PM2.5 more than the reductions in SO2 and NOx emissions alone. 4. Process analysis and sensitivity studies showed southeastern U.S. is NH3-rich or neutral. The fate of reduced N and total nitrate is dominated by that of NH3 and HNO3, respectively. 5. Source appointment showed that agricultural emissions are within the top 3 contributors to PM2.5 (by 8-12%) among 10 major sources in eastern U.S. 6. Inline dry deposition affects O3, HNO3, SO2, and NOx. H2S/NH3 reactions affect O3, SO2, and SO42-. Bi-directional NH3 exchange affects NH3, NHx, NO3-, PM2.5, total N and its deposition, NH3 to NH4+ conversion, and PM2.5 formation regimes. Simulated NHx is highly sensitive to parameters in the bi-directional exchange scheme. Two-layer bi-directional treatments of NH3 are recommended. 7. The 2018 runs with projected anthropogenic emissions but 2002 meteorology project decreased PM2.5, improved visibility, slight decreased O3 in urban areas in July, and decreased total N deposition in most areas. Emission control strategies should consider region-specific seasonality and differences in the responses of O3, PM2.5, visibility, and N deposition. 8. CMAQ v5.0 runs for 2026-2030 and 2046-2050 with changes in climate and anthropogenic/biogenic emissions showed increased temperatures and decreased ventilation in the future, leading to increased O3 over the eastern U.S. in winter and decreased O3 over the U.S. in summer. Future PM2.5 decreases due mainly to decreased anthropogenic emissions. Anthropogenic emission projections dominate over changes in climate. Changes in some regions/species are dominated by climate and/or both climate and anthropogenic emissions. Improvements in air quality due to emission reductions may be offset by degradation due to climate change in some regions, which should be considered by policy makers.
Publications
- Wang, K. and Y. Zhang, 2012, Application, evaluation, and process analysis of U.S. EPA 2002 multiple-pollutant air quality modeling platform, Atmospheric and Climate Sciences, 2(3), 2012-07-26, DOI: 10.4236/acs.2012.23025.
- Wang, K., Y. Zhang, A. Nenes, and C. Fountoukis, 2012, Implementation of Dust Emission and Chemistry into the Community Multiscale Air Quality Modeling System and Initial Application to An Asian Dust Storm Episode, Atmospheric Chemistry and Physics, 12, 10209-10237, doi:10.5194/acp-12-10209-2012.
- Liu, X.-H. and Y. Zhang, 2013, Understanding of the Formation Mechanisms of Ozone and Particulate Matter at a fine scale over the Southeastern U.S.: Process Analyses and Responses to Future-Year Emissions, Atmos. Environ., in press.
- Zhang, Y., K., Olsen, and K. Wang, 2013, Fine Scale Modeling of Agricultural Air Quality over the Southeastern United States using Two Air Quality Models, Part I. Application and Evaluation, Aerosol and Air Quality Research, in press.
- Zhang, Y., and S.-Y. Wu, 2013, Fine Scale Modeling of Agricultural Air Quality over the Southeastern United States using Two Air Quality Models, Part II. Sensitivity Studies and Policy Implications, Aerosol and Air Quality Research, in press.
- Zhang, Y., 2010, Recent Progress and Major Challenges of Air Quality/Climate Modeling, invited seminar at the Shanghai Chinese Academy of Sciences, Shanghai, China, August 10.
- Zhang, Y., 2010, A Comparative Study of Nucleation Parameterizations using box and 3-D models, invited seminar at the Institute of Environmental Sciences and Engineering, Peking University, Beijing, China, July 21.
- Zhang, Y., 2009, Recent Progress in Modeling Air Quality/Climate at NCSU, invited seminar at the Department of Environmental Science, Sun Yat-sen University, Guangzhou, China, November 10.
- Zhang, Y., 2009, Modeling Regional and Global Air Quality and Its Interactions with Climate, invited seminar at Shanghai Jiaotong University, Shanghai, China, July 1.
- Zhang, Y., 2009, Simulating Air Quality using CMAQ and WRF/Chem, invited seminar at the Department of Environmental Science and Engineering, Tsinghua University, Beijing, China, June 29.
- Zhang, Y., 2008, Air Quality/Climate Research at NCSU: Road Map, Milestones, and Outlook, invited seminar at the Office of Air Quality Planning & Standards, the U.S. EPA, Research Triangle Park, NC, July 15. Zhang, Y., 2008, 3-D Air Quality and Climate Modeling: Tools, Progress, and Challenges, invited seminar at the Department of Environmental Science & Engineering, Fudan University, Shanghai, China, April 16.
- Zhang, Y., 2008, Air Quality Research at North Carolina State University and beyond, invited seminar at Shanghai Jiaotong University, Shanghai, China, April 16.
- Wang, K. and Y. Zhang, 2013, 3-D agricultural air quality modeling: impacts of gas-phase reactions involving NH3/H2S and bidirectional exchange of NH3, Atmos. Environ., in preparation.
- Wang, K. and Y. Zhang, 2013, Bidirectional exchanges of NH3: Box model intercomparisons and evaluation using field experimental data, Atmos. Environ., in preparation.
- Zhang, Y., D. Loughlin, and R. L. Leung, 2013, Future emission projections and their impact on air quality, J. Geophys. Res., in preparation.
- Zhang, Y., K. Wang, P. Livingstone, C. K. Chan, and S.-C. Yu, 2013, Evaluation of Inorganic Aerosol Thermodynamic Equilibrium Modules for Simulating Gas/Particle Partitioning, Atmos. Environ., in preparation.
- Penrod, A., Y. Zhang, K. Wang, S.-Y. Wu, and R. L. Leung, 2013, Impact of Future Climate Predictions and Emissions on Air Quality Over the U.S.: Application, Evaluation, and Sensitivity Study, J. Geophys. Res., in preparation.
- Wang, W., S.-Y. Wu, K. Wang, Y. Zhang, H. Minoura, and Z. Wang, 2012, Impact of Updated Emission Inventories on Source Apportionment of Fine Particle and Ozone over the southeastern U.S., oral presentation at the 31th AAAR annual conference, October 8-12, Minneapolis, Minnesota, USA.
- Penrod, A., K. Wang, and Y. Zhang, 2012, Future Air Quality: Degradation or Improvement due to Climate and Emissions Poster presentation at the 7th Annual NC State University Graduate Student Research Symposium, March 20, 2012, McKimmon Center, NCSU, Raleigh, NC.
- Zhang, Y., 2011, Modeling Transport, Chemistry, and Climatic Impacts of Particulate Matter at Regional and Global Scales: Model Capabilities, Deficiencies, and Uncertainties, invited keynote speech at the 2011 Bouyoucos Conference on Synchrotrons for Soils, Estes Park, CO, August 1 -2.
- Zhang, Y., A. Penrod, and K. Wang, 2011, Impact of Regional Climate/Emission Changes on Air Quality over U.S.: Concentration, Deposition, and Visibility, invited presentation at the 8th International Conference on Acid Deposition (Acid Rain 2011), Beijing, China, June 15-18.
- Zhang, Y., K. Wang, Penrod, A., W. Robarge, and J. Walk, 2011, 3-D Agricultural Air Quality Modeling: The State Of The Science, Fine-Scale Applications, and Policy Implications. Part I. Impacts of Bidirectional Exchange of NH3 and Reactions involving NH3/H2S, poster presentation at the 2011 USDA Air Quality Project Directors Meeting, June 7, Washington D.C.
- Penrod, A., K. Wang, Zhang, Y., 2011, 3-D Agricultural Air Quality Modeling: The State Of The Science, Fine-Scale Applications, and Policy Implications. Part II. Impacts of Future Climate and Emissions on Air Quality, poster presentation at the 2011 USDA Air Quality Project Directors Meeting, June 7, Washington D.C.
- Zhang, Y., K. Wang, W. Robarge, and J. Walker, 2010, Agricultural Air Quality Modeling: Impact of Revised Modules and Future Climate Change, oral presentation at the 2010 AFRI Air Quality Project Directors (PD) Meeting, Amarillo, TX, August 23-24.
- Wu, S.-Y., Y. Zhang, K. Wang, and Ruby Leung, 2010, Impact of Projected Future Climate Change on Regional Air Quality in the U.S., poster presentation at the 2010 Western Pacific Geophysics Meeting, 22-25 June 2010, Taipei, Taiwan.
- Zhang, Y., 2010, Combat Air Pollution in a Changing Climate: Sciences, Modeling Tools, and Strategies, oral presentation at the 3rd International Conference on Environmental Technology and Knowledge Transfer (3rd ICET), May 13-14, 2010, Hefei, Anhui Province, China.
- Zhang, Y. and S.-Y., Wu, 2013, Understanding of the Fate of Atmospheric Pollutants using a Process Analysis Tool in a 3-D Regional Air Quality Model at a Fine Grid Scale, Atmospheric and Climate Sciences, 3 (1), 18-30.
- Wang, W., S.-Y. Wu, K. Wang, Y. Zhang, H. Minoura, and Z.-F. Wang, 2013, Impact of Updated Emission Inventories on Source Apportionment of Fine Particle and Ozone over the southeastern U.S., Atmos. Environ., in preparation.
- Burr, M. and Y. Zhang, 2010, Evaluation of Source Apportionment and Source Sensitivity of Fine Particulate Matter, oral presentation at the 12th conference on Atmospheric Chemistry of the 2010 AMS Annual Meeting, January 17-21, 2010, Atlanta, GA.
- Zhang, Y., Y.-S. Chen, P. Pillai, and X.-Y. Dong, 2009, Sensitivity of Simulated Aerosol and Cloud Properties to Nucleation Parameterizations in 3-D Regional and Global Models, poster presentation at the 28th Annual Meeting of AAAR, October 26-30, Minneapolis, MN.
- Olsen, K.M., Y. Zhang, J. Walker, and W. Robarge, 2009, Assessing the Impacts of Reduced SO2, NOx, and Agricultural Livestock NH3 Emissions on Air Quality in the Southeastern U.S., poster presentation at the 8th annual CMAS meeting, October 19-21, Chapel Hill, NC.
- Dong, X.-Y. and Y. Zhang, 2009, Simulating Transport and Fate of Agriculturally-Emitted Species using CMAQ, poster presentation at the 8th annual CMAS meeting, October 19-21, 2009, Chapel Hill, NC.
- Zhang, Y., K. M. Olsen, X.-H. Liu, W. Robarge, J. Walker, 2009, Agricultural Air Quality Application of CMAQ and CAMx at a Fine Scale, oral presentation at the 2009 Joint Annual Meeting of the National Research Initiative Air Quality Project Directors: Improving the Sustainability of Livestock and Poultry Production in the United States (S-1032) and Systems for Controlling Air Pollutant Emissions and Indoor Environments of Poultry, Swine, and Dairy Facilities (S-1025), Kansas City, MO, June 2-4.
- Zhang, Y., K. M. Olsen, and X.-H. Liu, 2009, Agricultural Air Quality Applications of CMAQ: Fine Scale Simulation, Evaluation, and Policy Implications, poster presentation at the 30th NATO/SPS International Technical Meeting on Air Pollution Modelling and its Application, 18-22 May 2009, San Francisco, CA.
- Liu, X.-H., K. M. Olsen, Y. Zhang, and W.-X. Wang, 2009, Simulating Air Quality in the Southeastern U.S.: Process Analyses and Responses to Future-Year Emissions, poster presentation at the 11th Conference on Atmospheric Chemistry/the 89th AMS Annual Meeting, Phoenix, AZ, January 11-15, 2009.
- Liu, X.-H., Y. Zhang, S.-Y. Wu, and W.-X. Wang, 2008, The Impact of Emission Reductions on Future Air Quality over North Carolina, poster presentation at the 27th Annual Meeting of American Association for Aerosol Research, Orlando, FL October 20-24.
- Olsen, K., Zhang, Y., Walker, J., and Robarge, W. 2008. Impact of Reduced Nitrogen on Air Quality: Fine Scale Simulation, Evaluation, and Sensitivity Study, extended abstract in Conference Proceedings and oral presentation at the 7th Annual CMAS Conference, Chapel Hill, NC, October 6-8, http://www.cmascenter.org/conference/2008/agenda.cfm
- Liu, X.-H., Zhang, Y., Walker, J., Robarge, W., and Wang, W.-X. 2008. Simulating Gas/Particle Partitioning of Total Nitrate and Reduced Nitrogen over North Carolina using Three Inorganic Aerosol Thermodynamic Modules, poster presentation at the CSREES, USDA, National Research Initiative, NRI 28.0 Air Quality, Annual Program Directors Meeting, Research Triangle Park, NC, July 23-24.
- Olsen, K. and Zhang, Y. 2008. Modeling the Fate and Impact of Reduced Nitrogen over the Southeastern United States, poster presentation at the CSREES, USDA, National Research Initiative, NRI 28.0 Air Quality, Annual Program Directors Meeting, Research Triangle Park, NC, July 23-24.
- Olsen, K. M., Wu, S.-Y., Frazier, E., and Zhang, Y. 2008. Fine-scale Modeling of Air Quality Using Two Air Quality Models Over the Southeastern United States, poster presentation at the 2008 NCSU Graduate Student Research Symposium, McKimmon Center, NCSU, Raleigh, NC, March 19.
- Zhang, Y., 2012, 3-D Air Quality and Climate Modeling using CMAQ and WRF/Chem, invited seminar at the University of Tokyo, Tokyo, Japan, August 20.
- Zhang, Y., 2012, 3-D Air Quality Modeling: Sciences, Tools, and Policy Implications, invited seminar at the Central Research Institute of Electric Power Industry, Tokyo, Japan, August 15.
- Zhang, Y., 2012, Recent Advances in Secondary Organic Aerosol Modeling, invited seminar at the School of Environment, Tsinghua University, Beijing, China, August 8.
- Zhang, Y., 2012, Recent Progress in Regional Air Quality Modeling, invited seminar at the School of Human Settlement and Civil Engineering, Xi an Jiaotong University, Xi an, China, August 3.
- Zhang, Y., 2012, Three-dimensional Air Quality Modeling: Gas-Phase Chemistry and Aerosol Treatments, invited seminar at the College of Environmental Sciences and Engineering, Peking University, Beijing China, July 25.
- Zhang, Y., 2011, Regional Air Quality Modeling: Development, Application, and Evaluation, invited seminar at the Department of Environmental Science, Sun Yat-sen University, Guangzhou, China, June 27.
- Zhang, Y., 2011, A Comparative Review of Nucleation Parameterizations for New Particle Formation, Part II: 3-D Model Application and Evaluation, invited seminar at the Department of Environmental Science and Engineering, Tsinghua University, Beijing, China, June 14.
- Zhang, Y., 2011, A Comparative Review of Nucleation Parameterizations for New Particle Formation, Part I: Box Model Examination and Evaluation, invited seminar at the Department of Environmental Science and Engineering, Tsinghua University, Beijing, China, June 14.
- Zhang, Y., 2011, Regional Air Quality Modeling with WRF/Chem, WRF/CMAQ, and MM5/CMAQ, invited seminar at the University of Hertfordshire, College Lane, Hatfield, UK, April 8.
- Zhang, Y., 2010, Nucleation Parameterizations for New Particle Formation: A Comparative Review, invited seminar at the Max Planck Institute for Chemistry, Mainz, Germany, November 5.
- Liu, X.-H., Y. Zhang, K. Olsen, W.-X. Wang, B. Do, and G. Bridgers, 2010, Responses of Future Air Quality to Emission Controls over North Carolina, Part I: Model Evaluation for Current-Year Simulations, Atmos. Environ., 44(23), 2443-2456.
- Zhang, Y., X.-H. Liu, K. Olsen, W.-X. Wang, B. Do, and G. Bridgers, 2010, Responses of Future Air Quality to Emission Controls over North Carolina, Part II: Analyses of Future-Year Predictions and Their Policy Implications, Atmos. Environ., 44 (23), 2767-2779.
- Zhang, Y., P. McMurry, F. Yu, and M.Z. Jacobson, 2010, A Comparative Study of Homogeneous Nucleation Parameterizations, Part I. Examination and Evaluation of the Formulations, J. Geophys. Res., 115, D20212, doi:10.1029/2010JD014150.
- Zhang, Y., P. Liu, X.-H. Liu, M.Z. Jacobson, P. McMurry, F. Yu, S.-C. Yu, and K. Schere, 2010, A Comparative Study of Homogeneous Nucleation Parameterizations, Part II. 3-D Model Application and Evaluation, J. Geophys. Res., 115, D20213, doi:10.1029/2010JD014151.
- Burr, M.B. and Y. Zhang, 2011, Source Apportionment of PM2.5 over the Eastern U.S. using CMAQ, Part II: Source Apportionment Simulations using CAMx/PSAT and Comparisons with CMAQ Source Sensitivity Simulations, Atmospheric Pollution Research, 2, 318-336.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: 3-D Model Application Activities and Products (1) Five sets of final sensitivity simulations using CMAQv4.7 have been conducted at a 12-km horizontal resolution for January and July 2002 to evaluate the importance of several model treatments including inline dry deposition calculation, new reactions of NH3 and H2S, and bidirectional exchange treatment. (2) Five additional sensitivity simulations using CMAQv4.7 have been conducted at a 12-km horizontal resolution for July 2002 to evaluate the sensitivity of the model predictions to three important parameters in the bidirectional exchange of NH3 treatment (3) We conducted our final production simulations using the latest version of CMAQ released in Feb., 2012, i.e., CMAQ v5.0. WRF/CMAQ5.0 simulations over continental U.S. were conducted for five current (2001-2005) and five future years (2026-2030) winter and summer. For future year simulations, we consider changes in both climate and emissions (including anthropogenic and biogenic emissions). Results from NCAR's global climate model CCSM are used to initiate WRF simulations to provide meteorological inputs needed for CMAQ simulations. (4) we conducted one sensitivity simulation of WRF/CMAQ over the hottest summer during 2029 with the projected climate change and biogenic emissions that depend on climate change. PARTICIPANTS: Dr. Yang Zhang, Project Director, NCSU, overseeing the project, conducting nucleation module intercomparison, advising students on model development, application, and evaluation tasks. Dr. Wayne Robarge, co-PD, NCSU, providing measurement data for model validation and review conference presentations. Dr. John Walker, co-PD, the U.S. EPA, providing measurement data for model validation and review conference presentations. Mr. Kai Wang, PhD student during Jan. 1- Sept. 14, 2011 and post-D during Sept. 15-Dec. 31, 2011, NCSU, conducting MM5/CMAQ baseline and sensitivity simulations at 12-km. Ms. Ashley Penrod, conduct WRF/CMAQ simulations at 36-km for 2001-2005 and 2026-2030. Mr. Wei Wang, assist in the installation of the model evaluation tool and post-processing results. Collaborators: Dr. Ruby Leung, Pacific Northwest National laboratory, provided CCSM post-processed files to initialize WRF simulations Ms. Shiang-Yuh Wu, Department of Air Quality & Environmental Management, Clark County, NV, assisted in model evaluation tool and post-processing results. TARGET AUDIENCES: Students (undergraduate and graduate), post-D research fellows, researchers in scientific community, external organizations and stakeholder groups including the NCDAQ, the NC Pork Council, the National Pork Board, River Keepers. PROJECT MODIFICATIONS: No major modifications except that we used the latest version of CMAQ v5.0 which contains more advanced model treatments than the older version (CMAQ v4.7) for future climate change impact simulations
Impacts
(1) Inline dry deposition for all gases and NH3/H2S reactions have limited effects on SO2, SO42-, and PM2.5. Bidirectional exchange of NH3 can have much larger effects on predicted species concentrations. It can also affect nitrogen deposition, conversion of NH3 to NH4+, and the indicator for PM formation regimes (e.g., change from NH3-poor to NH3-rich in some areas). (2) The model results are highly sensitive to the apoplastic ratio ([NH4+]/[H+] and the empirical constants (A and B) in the calculation of the stomatal compensation point in the bidirectional exchange of NH3 treatment. The use of the default set of the apoplastic ratios (sens4) or the lower bound of the apoplastic ratios (sens5) in CMAQv5.0 decreases the stomatal compensation point, which leads to lower concentrations of NH3, NHx, total nitrogen (TN), NH4NO3, and PM2.5 and lower wet deposition of TN but higher concentrations of HNO3, O3, dry deposition of TN, and total deposition of TN. In contrast, the use of the upper bound and mean values of the apoplastic ratios (sens6 and sens7) leads to the opposite changes for those concentrations and deposition fluxes. The impact of different empirical constants on model predictions is similar to that of the use of lower bound apoplastic ratios, because they decrease the stomatal compensation point. (3) Based on our latest simulations using WRF/CMAQv5.0, the O3 concentrations will decrease over most of the U.S. in summer and the western U.S. in winter due to reduced emissions of precursors (e.g., NOx), and the slight increase in the eastern U.S. in winter may be due to increased T2 and atmospheric stability. The PM2.5 concentrations will decrease in summer and winter over most of the U.S., due mainly to decreases in emissions of precursors (e.g., SO2, primary PM2.5) in both seasons and increased precipitation in winter. The concentrations of secondary organic aerosols will increase over most of the U.S. in the summer and some areas in the eastern U.S. due to increased biogenic emissions resulted from increased T2. In winter, SOA level decreases over a large area due to decreases in biogenic emissions over the northwestern U.S. and decreases in its precursor level in these areas resulted from increased T2. Wet deposition of total nitrogen will change in either direction. The increases (e.g., the southeastern U.S.) are due to increased precipitation and scavenging as well as increased ammonia emissions. The decreases (e.g., the northeastern U.S.) are due to decreased precipitation. (4) Improvements in AQ due to emission reductions may be offset by degradation due to climate change in some regions (e.g., the Midwest and the Gulf Coast for O3 and the western U.S. for PM2.5). Policy makers need to recognize the degradation of AQ caused by adverse climate changes, and enforced even more drastic emission reductions. In addition, areas with reduced PM2.5 level may have increased SOA driven by climate warming, which in turn affects climate via serving as cloud condensation nuclei.
Publications
- Burr, M.B. and Y. Zhang, 2011, Source Apportionment of PM2.5 over the Eastern U.S. using CMAQ, Part II: Source Apportionment Simulations using CAMx/PSAT and Comparisons with CMAQ Source Sensitivity Simulations, Atmospheric Pollution Research, 2, 318‐336. Penrod, A., K. Wang, and Y. Zhang, 2012, Future Air Quality: Degradation or Improvement due to Climate and Emissions Poster presentation at the 7th Annual NC State University Graduate Student Research Symposium, March 20, 2012, McKimmon Center, NCSU, Raleigh, NC. Zhang, Y., 2011, Modeling Transport, Chemistry, and Climatic Impacts of Particulate Matter at Regional and Global Scales: Model Capabilities, Deficiencies, and Uncertainties, invited keynote speech at the 2011 Bouyoucos Conference on Synchrotrons for Soils, Estes Park, CO, August 1 -2. Zhang, Y., A. Penrod, and K. Wang, 2011, Impact of Regional Climate/Emission Changes on Air Quality over U.S.: Concentration, Deposition, and Visibility, invited presentation at the 8th International Conference on Acid Deposition (Acid Rain 2011), Beijing, China, June 15-18. Zhang, Y., K. Wang, Penrod, A., W. Robarge, and J. Walk, 2011, 3-D Agricultural Air Quality Modeling: The State Of The Science, Fine-Scale Applications, and Policy Implications. Part I. Impacts of Bidirectional Exchange of NH3 and Reactions involving NH3/H2S, poster presentation at the 2011 USDA Air Quality Project Directors Meeting, June 7, Washington D.C. Penrod, A., K. Wang, Zhang, Y., 2011, 3-D Agricultural Air Quality Modeling: The State Of The Science, Fine-Scale Applications, and Policy Implications. Part II. Impacts of Future Climate and Emissions on Air Quality, poster presentation at the 2011 USDA Air Quality Project Directors Meeting, June 7, Washington D.C. Penrod, A., 2012, Examining the Impacts of Future Climate and Emissions on Regional Air Quality Using WRF/CMAQ: Application, Evaluation, and Sensitivity Study, MS Thesis, NCSU, Raleigh, NC, July, 2012.
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: 3-D Model Application Activities and Products (1) Four sets of sensitivity simulations using CMAQ have been conducted at a 12-km horizontal resolution for January and July 2002 to evaluate the importance of several model treatments including inline dry deposition calculation, new reactions of NH3 and H2S, and bidirectional exchange treatment: a. A simulation with default CMAQ using the Asymmetric Convective Model, version 2, (ACM2) mixing scheme (base acm2) b. A simulation with default CMAQ using the acm2inline scheme and no NH3 bidirectional exchange treatment (base acm2inline) c. A simulation with revised CMAQ (with addition of 19 new gas-phase reactions of NH3 and H2S and 1 aqueous-phase reaction of NH3) using acm2inline and no NH3 bidirection exchange treatment (sens1) d. A simulation with revised CMAQ using the acm2inline scheme and with NH3 bidirectional exchange treatment (sens2). We are analyzing those results to understand the impact of inline dry deposition calculation, new reactions involving NH3 and H2S and NH3 bidirectional exchange on model predictions. Note that those simulations are initial tests, we are set up final production simulations. (2) We applied two approaches to identify major source categories leading to PM2.5 formation. One based on brute force method (BFM) using 3-D CMAQ in which we shut off emissions from one source category and compare results from baseline simulation (referred to as CMAQ/BFM). The other based on PM Source Apportionment (PSAT) method embedded in 3-D CAMx (referred to as CAMx/BFM). (3) We conducted WRF/CMAQ simulations over continental U.S. for one current year (2002) and five future years (2026-2030). For future year simulations, we consider changes in both climate and emissions (including anthropogenic and biogenic emissions). Results from NCAR's global climate model CCSM are used to initiate WRF simulations to provide meteorological inputs needed for CMAQ simulations. PARTICIPANTS: Participants: Dr. Yang Zhang, Project Director, NCSU, overseeing the project, conducting nucleation module intercomparison, advising students on model development, application, and evaluation tasks. Dr. Wayne Robarge, co-PD, NCSU, providing measurement data for model validation. Dr. John Walker, co-PD, the U.S. EPA, providing measurement data for model validation. Mr. Kai Wang, PhD student, NCSU, conducting MM5/CMAQ simulations at 12-km. Mr. Xinyi Dong, PhD student, improving gas-phase chemistry involving NH3 and H2S of MM5/CMAQ and testing a module for bidirectional exchange of NH3. Mr. Mike Burr, conducted source apportionment simulations using CMAQ/BFM and CAMx/PSAT Ms. Ashley Penrod, conduct WRF/CMAQ simulations at 36-km for 2002 and 2026-2030. Collaborators: Dr. Ruby Leung, Pacific Northwest National laboratory, provided CCSM post-processed files to initialize WRF simulations Ms. Shiang-Yuh Wu, Department of Air Quality & Environmental Management, Clark County, NV, initiate WRF/CMAQ future year simulations using CCSM outputs TARGET AUDIENCES: students (undergraduate and graduate), post-D research fellows, researchers in scientific community, external organizations and stakeholder groups including the NCDAQ, the NC Pork Council, the National Pork Board, River Keepers. PROJECT MODIFICATIONS: No major modifications
Impacts
1. Our preliminary analysis shows that the bidirectional exchange treatment for NH3 may change NH3 in both directions (e.g., decrease it by up to 0.5 ppb or increase it by up to 1.5 ppb), with increases dominating, resulting in an increased PM2.5 by up to (~8.5%) in Jan and up to ~14.8% in Jul. 2. In Jul, the new NH3/H2S reactions increase domainwide concentrations of SO2 by up to 11.8%, and reduce those of NH3 by up to 9.2%, which slightly increase domainwide concentrations of NH4+, SO42-, and PM2.5 by up to 3.5%, 4.3%, and 3%, respectively. Smaller effects are found in January. 3. Source appointment results show that the top three sources for PM2.5 concentrations domainwide in January are identified to be coal combustion (with a monthly-mean contribution of 14.0%), biomass burning (11.3%) and other mobile sources (6.8%) by CAMx/PSAT but biomass burning (13.7%), miscellaneous area sources (11.8%), and coal combustion (10.8%) by CMAQ/BFM. Both agree that coal combustion, industrial processes, and miscellaneous area sources are the top three sources in July, though they differ in the magnitude of contributions. Among these sources, miscellaneous area sources contain largely emissions of NH3 from agricultural activities, which contribute significantly to PM2.5 formation in both months. 4. WRF predicts a future climate with higher surface temperature and relative humidity in most areas in both summer and winter. Wind speed at 10-m may change in either directions. Boundary layer height will be lower over most areas in summer and in central and eastern U.S. in winter. Precipitation will be lower in northern U.S. in summer but higher over most areas in winter. 5. Anthropogenic emissions of SO2, NOx, and primary PM2.5 in future years are projected to decrease by 75%, 28%, and 10-20%, respectively, from the levels of 2002, due to emission control efforts. Those of NH3 and HCHO will increase by 34% and 14%, respectively, reflecting growths in certain sectors such as agriculture. Biogenic emissions will increase by > 100% domainwide in summer and winter, due to higher surface temperature. 6. Several changes may occur in responses to a changing climate and projected emissions: a. Max 8-hr avg O3 level will increase by a few ppb (by 5-10%) in most areas in northern U.S. in summer and eastern U.S. in winter, due to increased isoprene and formaldehye; b. PM2.5 level will increase by a few ug m-3 (< 50%) in western U.S. in summer and northeastern U.S. in winter, due to increases in inorganic and organic PM driven by higher temperatures; c. Similar increases occur in secondary organic aerosol due to higher biogenic emissions and primary OM due to a more stable atmosphere that offsets reduced emissions and concentrations in the remaining regions. However, such increases are compensated by decreased inorganic aerosols resulted from emission control, leading to decreased PM2.5 concentrations; d. Changes in visibility correspond to changes in PM2.5, with a worse visibility in western U.S. in summer and northeastern U.S. in winter; e. Total nitrogen deposition will increase in most domain in summer and winter, driven by increased NH3, NH4+ and NO3-.
Publications
- Burr, M.B. and Y. Zhang, 2011, Source Apportionment of PM2.5 over the Eastern U.S. using CMAQ, Part II: Source Apportionment Simulations using CAMx/PSAT and Comparisons with CMAQ Source Sensitivity Simulations, Atmospheric Pollution Research, in press.
- Zhang, Y., P. Liu, X.-H. Liu, M.Z. Jacobson, P. McMurry, F. Yu, S.-C. Yu, and K. Schere, 2010, A Comparative Study of Homogeneous Nucleation Parameterizations, Part II. 3-D Model Application and Evaluation, J. Geophys. Res., 115, D20213, doi:10.1029/2010JD014151.
- Liu, X.-H., Y. Zhang, K. Olsen, W.-X. Wang, B. Do, and G. Bridgers, 2010, Responses of Future Air Quality to Emission Controls over North Carolina, Part I: Model Evaluation for Current-Year Simulations, Atmos. Environ., 44(23), 2443-2456.
- Zhang, Y., P. McMurry, F. Yu, and M.Z. Jacobson, 2010, A Comparative Study of Homogeneous Nucleation Parameterizations, Part I. Examination and Evaluation of the Formulations, J. Geophys. Res., 115, D20212, doi:10.1029/2010JD014150.
- Zhang, Y., X.-H. Liu, K. Olsen, W.-X. Wang, B. Do, and G. Bridgers, 2010, Responses of Future Air Quality to Emission Controls over North Carolina, Part II: Analyses of Future-Year Predictions and Their Policy Implications, Atmos. Environ., 44 (23), 2767-2779.
- Zhang, Y., K. Wang, W. Robarge, and J. Walker, 2010, Agricultural Air Quality Modeling: Impact of Revised Modules and Future Climate Change, oral presentation at the 2010 AFRI Air Quality Project Directors (PD) Meeting, Amarillo, TX, August 23-24.
- Wu, S.Y., Y. Zhang, K. Wang, and Ruby Leung, 2010,Impact of Projected Future Climate Change on Regional Air Quality in the U.S., poster at the 2010 Western Pacific Geophysics Meeting, June 22-25, Taiwan.
- Zhang, Y., 2010, Combat Air Pollution in a Changing Climate: Sciences, Modeling Tools, and Strategies, oral presentation at the 3rd International Conference on Environmental Technology and Knowledge Transfer (3rd ICET), May 13-14, 2010, Hefei, Anhui Province, China.
- Burr, M. and Y. Zhang, 2010, Evaluation of Source Apportionment and Source Sensitivity of Fine Particulate Matter, oral presentation at the 12th conference on Atmospheric Chemistry of the 2010 AMS Annual Meeting, January 17-21, 2010, Atlanta, GA.
- Zhang, Y., 2010, Nucleation Parameterizations for New Particle Formation: A Comparative Review, invited seminar at the Max Planck Institute for Chemistry, Mainz, Germany, November 5.
- Zhang, Y., 2010, Recent Progress and Major Challenges of Air Quality/Climate Modeling, invited seminar at the Shanghai Chinese Academy of Sciences, Shanghai, China, August 10.
- Zhang, Y., 2010, A Comparative Study of Nucleation Parameterizations using box and 3-D models, invited seminar at the Institute of Environmental Sciences and Engineering, Peking University, Beijing, China, July 21.
- Mike Burr, 2010 Source Apportionment of PM2.5 using Three-Dimensional Air Quality Models: Analysis and Inter-Comparison of Two Source Apportionment Methods, MS Thesis, NCSU, Raleigh, NC, July, 2010, advised by Yang Zhang.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Model/Module Development/Evaluation Activities and Products (1) We revised the box model containing the default gas-phase chemistry used in CMAQ by including more reactions involving agriculturally-emitted species. A total of 26 new reactions involving NH3, H2S, CH4, and N2O in the gas-phase and one reaction of NH3 with dissolved O3 in the aqueous-phase have been added. (2) Several binary, ternary, and power-law nucleation modules have been evaluated in CMAQ. Two manuscripts were completed and submitted to JGR-atmosphere for publication. (3) A newer version of inorganic aerosol thermodynamic module, ISORROPIA II, has been incorporated into CMAQ v4.7. Compared to ISORROIPA, ISORROPIA II treats additional salts involving crustal material such as K+, Ca2+, Mg2+, which are often associated with coarse particles emitted from agricultural and other sources. 3-D Model Application Activities and Products (1) Evaluation of baseline simulations using MM5/CMAQ at 4-km is being completed using all available observations for Jan., Apr., Jul., Aug., and Oct. over the southeastern U.S. The detailed process analysis is being conducted. For Jan. and Jul., simulations with a second air quality model, CAMx, have also been completed and compared with CMAQ. (2) Test simulations using CMAQ at 12-km with 19 new gas-phase reactions of NH3 and H2S and 1 aqueous-phase reaction of NH3 have been conducted for July 2002 to evaluate the importance of these reactions. (3) Two episodes were used to evaluate various nucleation modules. For the June 15-28 1999 SOS episode, CMAQ v4.4 simulations with 11 nucleation parameterizations were conducted. For the August 2002 episode, CMAQ v4.7 simulations with 4 nucleation parameterizations were conducted. These results were evaluated against observed particle number and size distributions and nucleation rates at an urban site in Atlanta in June 1999 and August 2002. (4) A sensitivity simulation using CAMx with 10 size sections at 4-km over the southeastern U.S. in July has been completed. The results are being compared with those with two size sections to evaluate the sensitivity of model predictions to particle size resolution. (5) CMAQ simulations with and without bidirectional exchange of NH3 have been conducted at 4-km. The impact of bidirectional exchange of NH3 on model predictions is evaluated. The above results have been disseminated at the following conferences, symposium, and workshops: 1. the 11th Conference on Atmospheric Chemistry/the 89th AMS Annual Meeting, Phoenix, AZ, January 11-15, 2009 2. the 30th NATO/SPS International Technical Meeting on Air Pollution Modelling and its Application, 18 - 22 May 2009, San Francisco, CA 3. the 2009 Joint Annual Meeting of the National Research Initiative Air Quality Project Directors: Improving the Sustainability of Livestock and Poultry Production in the United States (S-1032) and Systems for Controlling Air Pollutant Emissions and Indoor Environments of Poultry, Swine, and Dairy Facilities (S-1025), Kansas City, MO, June 2-4 4. the 8th annual CMAS meeting, October 19-21, 2009, Chapel Hill, NC 5. the 28th Annual Meeting of AAAR, October 26-30, 2009, Minneapolis, MN PARTICIPANTS: Individuals:Dr. Yang Zhang, Project Director, NCSU, overseeing the project, conducting nucleation module intercomparison, advising students on model development, application, and evaluation tasks. Dr. Wayne Robarge, co-PD, NCSU, providing measurement data for model validation. Dr. John Walker, co-PD, the U.S. EPA, providing measurement data for model validation. Dr. Ming-Tung Chuang, post-D, NCSU, conducting literature survey and initial module setup for NH3 dry deposition testing. Mr. Xinyi Dong, PhD student, improving gas-phase chemistry involving NH3 and H2S of CMAQ and testing a module for bidirectional exchange of NH3. Ms. Kristen Olsen, performing baseline MM5, CMAQ, and CAMx model application and evaluation at 4- and 1.33 km and sensitivity simulations under various emission reduction scenarios for Jan. and Jul 2002. Ms. Xiaohuan Liu, performing baseline MM5, CMAQ, and CAMx model application and evaluation at 4-km for Apr, Aug., and Oct. 2002 and CMAQ simulations for Jan., Apr, Aug., and Oct. 2018; aerosol thermodynamic module intercomparison; process analysis for Jan., Apr, Aug., and Oct. 2002. Collaborators: Dr. Jonathan Pleim, the U.S. EPA, providing a bidirectional exchange of NH3 parameterization implemented in CMAQ for box model study. Dr. YiWua Wu, the NWS/NCEP/NOAA, providing a multi-layer canopy resistance model of bi-directional NH3 exchange for box model study. TARGET AUDIENCES: students (undergraduate and graduate), post-D research fellows, researchers in scientific community, external organizations such as the US EPA and NCDAQ. Efforts: Science-based knowledge were delivered to people through formal classroom instruction, computer laboratory instruction, conferences and workshops, journal publications, and extension and outreach. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Major Findings and Impacts 1. The evaluation at 4-km show that both CMAQ and CAMx overpredict O3 and fine PM in Jan. and underpredict them in Jul. Compared with CMAQ, CAMx gives similar conversion rates of NH3 to NH4+ in Jan., but higher rates in Jul., possibly due to differences in vertical mixing, deposition, and aerosol treatments. The fate and transport of NH3 are assessed, with CAMx simulating larger areas of NH3-rich conditions in both months due to lower simulated total N. 2. Combined reduction of emissions of all three species (AL_NH3, NOx, and SO2) by 50% gives the largest reductions for PM2.5 by up to 19% and 18% and for N total deposition (dry + wet) by up to -42.5% and -48.5% in Jan. and Jul., respectively. These results indicate that reducing AL-NH3 emissions in conjunction with the projected SO2 and NOx reductions could reduce PM2.5 more than reductions in SO2 and NOx alone, particularly in Jan. 3. CMAQ test simulations for July 2002 show that the new NH3 and H2S reactions increase the domainwide concentration of SO2 by up to 9.7% , and reduce those of NH3 by up to 19.5%, which slightly increase (< 2.6%) the concentrations of NH4+ , SO42-, and PM2.5. The concentrations of NH4+, NO3-, SO42- , EC, OM, and PM2.5 remain underpredicted. Possible reasons may include uncertainties in emissions, inaccuracies in meteorological predictions, insufficient gas-to-particle conversion, and overpredicted wet deposition for SO42-. 4. Our studies show that none of the current ternary homogeneous nucleation parameterizations (THN) (i.e., Napari et al. (2002), Yu (2006), and Merikanto et al. (2007)) can accurately simulate the ternary nucleation rates. Among them, the THN of Napari et al. (2002) should not be used because it grossly overpredicts the observed nucleation rates, often exceeding the upper limit dimer or new particle formation rates, and giving an enhancement factor due to the presence of NH3 and a dependence on relative humidity that are inconsistent with laboratory measurements. 5. The crustal species associated with dust particles may potentially change the gas/particle partitioning processes. Our preliminary test simulations over continental U.S. in April 2001 show that the inclusion of these crustal species can decrease NH4+ by up to 0.65 g m-3 and increase NO3- by up to 0.5 g m-3 and NH3 by up to 1 ppb. This can be explained by the charge balance effect in which the dissolution of crustal cations will displace some NH4+ to neutralize ions (thus forcing some NH4+ to evaporate as NH3) and more dissolved ions are needed for neutralization. 6. Our preliminary test simulations using CMAQ at 4-km show that the bidirectional exchange treatment for NH3 may change NH3 in both directions (e.g., decrease it by up to 11.6 ppb (~84%) and increase it by up to 4.2 ppb), with increases dominating downmain-wide change. The net effect is an increase in PM2.5 concentrations by up to 0.8 g m-3 (~12%) through increasing NH4+, SO42-, and NO3-.
Publications
- Journal Publications: Xiao-Huan Liu, X.-Y. Dong, and Y. Zhang, 2010, Understanding of the Formation Mechanisms of Ozone and Particulate Matter at a fine scale over the Southeastern U.S.: Process Analyses and Responses to Future-Year Emissions, Atmos. Environ., in preparation. Olsen, K., Y. Zhang, S.-Y. Wu, W. Robarge, and J. Walker, 2010, Fine Scale Modeling of Agricultural Air Quality over the Southeastern United States, Part I. Application and Evaluation of Two Air Quality Models, Atmos. Environ., in preparation. Olsen, K., Y. Zhang, J. Walker, and W. Robarge, 2010, Fine Scale Modeling of Agricultural Air Quality over the Southeastern United States, Part II. Sensitivity Studies and Policy Implications, Atmos. Environ., in preparation. Zhang, Y., P. McMurry, F. Yu, and M.Z. Jacobson, 2010, A Comparative Study of Homogeneous Nucleation Parameterizations, Part I. Examination and Evaluation of the Formulations, J. Geophys. Res., in review. Zhang, Y., P. Liu, X.-H. Liu, M.Z. Jacobson, P. McMurry, F. Yu, S.-C. Yu, and K. Schere, 2010, A Comparative Study of Homogeneous Nucleation Parameterizations, Part II. 3-D Model Application and Evaluation, J. Geophys. Res., in review. Liu, X.-H., Y. Zhang, K. Olsen, W.-X. Wang, B. Do, and G. Bridgers, 2010, Responses of Future Air Quality to Emission Controls over North Carolina, Part I: Model Evaluation for Current-Year Simulations, Atmos. Environ., in review. Zhang, Y., X.-H. Liu, K. Olsen, W.-X. Wang, B. Do, and G. Bridgers, 2010, Responses of Future Air Quality to Emission Controls over North Carolina, Part II: Analyses of Future-Year Predictions and Their Policy Implications, Atmos. Environ., in press.
- Conference Proceeding Papers/Presentations: Zhang, Y., Y.-S. Chen, P. Pillai, and X.-Y. Dong, 2009, Sensitivity of Simulated Aerosol and Cloud Properties to Nucleation Parameterizations in 3-D Regional and Global Models, poster presentation at the 28th Annual Meeting of AAAR, October 26-30, Minneapolis, MN. Olsen, K.M., Y. Zhang, J. Walker, and W. Robarge, Assessing the Impacts of Reduced SO2, NOx, and Agricultural Livestock NH3 Emissions on Air Quality in the Southeastern U.S., poster presentation at the 8th annual CMAS meeting, October 19-21, Chapel Hill, NC. Dong, X.-Y. and Y. Zhang, 2009, Simulating Transport and Fate of Agriculturally-Emitted Species using CMAQ, poster presentation at the 8th annual CMAS meeting, October 19-21, Chapel Hill, NC. Zhang, Y., K. M. Olsen, X.-H. Liu, W. Robarge, J. Walker, 2009, Agricultural Air Quality Application of CMAQ and CAMx at a Fine Scale, oral presentation at the 2009 Joint Annual Meeting of the National Research Initiative Air Quality Project Directors:, Kansas City, MO, June 2-4. Zhang, Y., K. M. Olsen, and X.-H. Liu, 2009, Agricultural Air Quality Applications of CMAQ: Fine Scale Simulation, Evaluation, and Policy Implications, poster presentation at the 30th NATO/SPS International Technical Meeting on Air Pollution Modelling and its Application, May 18-22, San Francisco, CA. Liu, X.-H., K. M. Olsen, Y. Zhang, and W.-X. Wang, 2009, Simulating Air Quality in the Southeastern U.S.: Process Analyses and Responses to Future-Year Emissions, poster presentation at the 11th Conference on Atmospheric Chemistry/the 89th AMS Annual Meeting, Phoenix, AZ, January 11-15.
- Thesis: Kristen Olsen, 2009, Fine Scale Modeling of Agricultural Air Quality over the Southeastern United States: Application and Evaluation of Two Air Quality Models, MS Thesis, NCSU, Raleigh, NC, May.
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Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: Model/Module Development/Evaluation Activities and Products (1) A box model containing the default gas-phase chemistry used in CMAQ was developed. 15 additional reactions involving NH3, H2S, CH4, and N2O were added and their individual and combined impacts on gas-phase predictions are being examined. (2) Several binary and ternary nucleation modules are being tested in CMAQ for the June 15-28 1999 SOS episode. (3) Several dry deposition modules of NH3 including two bidirectional exchange schemes are being tested using flux measurements over soybean and corn provided by Dr. John Walker. (4) Three inorganic aerosol thermodynamic modules: ISORROPIA, EQUISOLV II, and AIM2, were tested using observations provided by Drs. Robarge and Walker to evaluate their performance in reproducing gas/particle partitioning. 3-D Model Application Activities and Products (1) Baseline model simulations using MM5 and default CMAQ were completed for 5 months: Jan., Apr., Jul., Aug., and Oct. at a horizontal grid spacing of 4-km over the southeastern U.S. While results from Jan., Apr., Jul. and Oct. provide seasonal contrast, the results of August will be used to evaluate various nucleation modules using observations in August 2002. These simulations include detailed process analysis that provides relative contribution of individual processes (e.g., transport, gas-phase chemistry, aerosol processes) to the concentration of key pollutants, as well as dominant reactions. For Jan. and Jul., a second air quality model, CAMx, has also been used to perform simulations and inter-compare with CMAQ. These results are being evaluated using available observational data. (2) Additional CMAQ and CAMx simulations at 1.33-km over the eastern North Carolina for Jan. and Jul. were also completed. These results will be used to study the role of NHx in PM2.5 formation at a local scale that is commensurate to the scales of agricultural operations and emissions. They, coupled with results at 4- and 12-km, are used to study the influence of grid resolution on model predictions. (3) Sensitivity simulations have been conducted for Jan. and Jul. 2002 with 4 emission control scenarios: 50% reductions in emissions of agricultural-livestock (AL) NH3, NOx, and SO2, one at one time, and in emissions of all these three species in one simulation. These results are being used to evaluate effectiveness of various emission control scenarios in controlling PM2.5. (4) CMAQ simulations of future year (2018) were completed for four months: Jan., Apr., Jul., and Oct using projected emission controls. These results are being analyzed with a focus on the new role of NH3 emissions in PM2.5 formation with projected reductions of NOx and SO2 emissions. Event Participation The above results have been disseminated at the following conferences, symposium, and workshops: 1. The 2008 NCSU Graduate Student Research Symposium, McKimmon Center, NCSU, Raleigh, NC, March 19, 2008 2. The CSREES, USDA, National Research Initiative, NRI 28.0 Air Quality, Annual Program Directors Meeting, Research Triangle Park, NC, July 23-24, 2008 3. The 7th Annual CMAS Conference, Chapel Hill, NC, October 6-8, 2008 PARTICIPANTS: Individuals: Dr. Yang Zhang, Project Director, NCSU, overseeing the project and conducting nucleation module intercomparison. Dr. Wayne Robarge, co-PD, NCSU, providing measurement data for model validation. Dr. John Walker, co-PD, the U.S. EPA, providing measurement data for model validation. Dr. Xiaoming Hu, post-D, NCSU, conducting literature survey and initial module setup for NH3 dry deposition testing. Mr. Xinyi Dong, PhD student, improving gas-phase chemistry of CMAQ. Ms. Kristen Olsen, performing baseline MM5, CMAQ, and CAMx model application and evaluation at 4- and 1.33 km and sensitivity simulations under various emission reduction scenarios for Jan. and Jul 2002. Ms. Xiaohuan Liu, performing baseline MM5, CMAQ, and CAMx model application and evaluation at 4- km for Apr, Aug., and Oct. 2002 and CMAQ simulations for Jan., Apr, Aug., and Oct. 2018; aerosol thermodynamic module intercomparison; process analysis for Jan., Apr, Aug., and Oct. 2002. Collaborators: Dr. Jonathan Pleim, the U.S. EPA, providing a bidirectional exchange of NH3 parameterization implemented in CMAQ for box model study. Dr. YiWua Wu, the NWS/NCEP/NOAA, providing a multi-layer canopy resistance model of bi-directional NH3 exchange for box model study. Training or professional development: This project provides training and professional development for three graduate students and 1 post-doctoral fellow to conduct research tasks and present their results at national/international conferences. TARGET AUDIENCES: Target audiences: students (undergraduate and graduate), post-D research fellows, researchers in scientific community. Efforts: Science-based knowledge were delivered to people through formal classroom instruction, computer laboratory instruction, and conferences and workshops. PROJECT MODIFICATIONS: A post-D hired in July 2008 resigned in Oct., 2008 unexpectedly. A new post-D was hired in March, 2009. This has set back the project progress in year 1, particularly in model development. However, with the new post-D in place, we hope to catch up in year 2.
Impacts
Major Findings and Impacts 1. The oxidation of NH3 by OH radicals may deplete NH3 by ~5% under typical ambient conditions ranging from remote to agricultural regions and could be higher under extreme conditions with massive NH3 emissions. Simulating this reaction in 3-D model can help improve accuracy of NH3 predictions. 2. ISORROPIA, EQUILSOLV II, and AIM2 modules reproduce well the gas/particle partitioning of total ammonium under all conditions. They give more TNO3 in the gas-phase than observations. Simulated TNO3 partitioning agrees better with observations under sulfate-poor and nighttime conditions. The preliminary box model results suggest that reducing total ammonium concentration is effective for cold season and sulfate-rich condition. 3. The preliminary 3-D model results show that the performance of CMAQ and CAMx is generally consistent with other 3-D air quality models. Compared with CMAQ, CAMx gives similar conversion rates of NH3 to NH4+ in Jan., but higher rates in Jul., possibly due to differences in vertical mixing, deposition, and aerosol treatments. 4. AL-NH3 reductions alone result in the largest decrease in January at up to 16%, dominated by a reduction in NH4NO3. The largest reductions of PM2.5 in both months occur when the emissions of all three species (AL_NH3, NOx, and SO2) are reduced by 50%, which results in a decrease of PM2.5 by up to 19% in January and 18% in July. These results indicate that reducing AL-NH3 emissions in conjunction with the projected SO2 and NOx reductions could act to reduce PM2.5 concentrations more than reductions in SO2 and NOx alone, particularly in winter. 5. The use of 4- and 1.33-km resolutions without adequate NH3 treatments does not significantly improve model performance. Further improvements in NH3 emissions, dispersion, chemistry, and dry/wet deposition as well as land use data are needed to improve model performance at a fine scale.
Publications
- Olsen, K., Zhang, Y., Walker, J., and Robarge, W. 2008. Impact of Reduced Nitrogen on Air Quality: Fine Scale Simulation, Evaluation, and Sensitivity Study, extended abstract in Conference Proceedings and oral presentation at the 7th Annual CMAS Conference, Chapel Hill, NC, October 6-8, http://www.cmascenter.org/conference/2008/agenda.cfm
- Liu, X.-H., Zhang, Y., Walker, J., Robarge, W., and Wang, W.-X. 2008. Simulating Gas/Particle Partitioning of Total Nitrate and Reduced Nitrogen over North Carolina using Three Inorganic Aerosol Thermodynamic Modules, poster presentation at the CSREES, USDA, National Research Initiative, NRI 28.0 Air Quality, Annual Program Directors Meeting, Research Triangle Park, NC, July 23-24.
- Olsen, K. and Zhang, Y. 2008. Modeling the Fate and Impact of Reduced Nitrogen over the Southeastern United States, poster presentation at the CSREES, USDA, National Research Initiative, NRI 28.0 Air Quality, Annual Program Directors Meeting, Research Triangle Park, NC, July 23-24.
- Olsen, K. M., Wu, S.-Y., Frazier, E., and Zhang, Y. 2008. Fine-scale Modeling of Air Quality Using Two Air Quality Models Over the Southeastern United States, poster presentation at the 2008 NCSU Graduate Student Research Symposium, McKimmon Center, NCSU, Raleigh, NC, March 19.
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