Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 9 23 2009 10.5194/acp-9-9169-2009 http://www.atmos-chem-phys.net/9/9169/2009/ http://www.atmos-chem-phys.net/9/9169/2009/acp-9-9169-2009.html http://www.atmos-chem-phys.net/9/9169/2009/acp-9-9169-2009.pdf 9169 9185 2009-12-07 A novel downscaling technique for the linkage of global and regional air quality modeling Y. F. Lam J. S. Fu jsfu@utk.edu Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN, USA Recently, downscaling global atmospheric model outputs (GCTM) for the USEPA Community Multiscale Air Quality (CMAQ) Initial (IC) and Boundary Conditions (BC) have become practical because of the rapid growth of computational technologies that allow global simulations to be completed within a reasonable time. The traditional method of generating IC/BC by profile data has lost its advocates due to the weakness of the limited horizontal and vertical variations found on the gridded boundary layers. Theoretically, high quality GCTM IC/BC should yield a better result in CMAQ. Unfortunately, several researchers have found that the outputs from GCTM IC/BC are not necessarily better than profile IC/BC due to the excessive transport of O₃ aloft in GCTM IC/BC. In this paper, we intend to investigate the effects of using profile IC/BC and global atmospheric model data. In addition, we are suggesting a novel approach to resolve the existing issue in downscaling. <br><br> In the study, we utilized the GEOS-Chem model outputs to generate time-varied and layer-varied IC/BC for year 2002 with the implementation of tropopause determining algorithm in the downscaling process (i.e., based on chemical (O₃) tropopause definition). The comparison between the implemented tropopause approach and the profile IC/BC approach is performed to demonstrate improvement of considering tropopause. It is observed that without using tropopause information in the downscaling process, unrealistic O₃ concentrations are created at the upper layers of IC/BC. This phenomenon has caused over-prediction of surface O₃ in CMAQ. In addition, the amount of over-prediction is greatly affected by temperature and latitudinal location of the study domain. With the implementation of the algorithm, we have successfully resolved the incompatibility issues in the vertical layer structure between global and regional chemistry models to yield better surface O₃ predictions than profile IC/BC for both summer and winter conditions. At the same time, it improved the vertical O₃ distribution of CMAQ outputs. It is strongly recommended that the tropopause information should be incorporated into any two-way coupled global and regional models, where the tropospheric regional model is used, to solve the vertical incompatibility that exists between global and regional models. Al-Saadi, J., Pierce, B., McQueen, J., Natarajan, M., Kuhl, D., Tang, Y. H., Schaack, T. K., and Grell, G.: Global Forecasting System (GFS) Project: Improving National chemistry forecasting and assimilation capabilities, Applications of Environmental Remote Sensing to Air Quality and Public Health, Potomac, MD, 8–9 May 2007. Bertschi, I. T., Jaffe, D. A., Jaegle, L., Price, H. U., and Dennison, J. B.: 2002 airborne observations of trans-Pacific transport of ozone, CO, volatile organic compounds, and aerosols to the northeast Pacific: Impacts of Asian anthropogenic and Siberian boreal fire emissions, J. Geophys. Res., 109, D23S12, doi:10.1029/2003JD004328, 2004. Bethan, S., Vaughan, G., and Reid, S. J.: A comparison of ozone and thermal tropopause heights and the impact of tropopause definition on quantifying the ozone content of the troposphere, Q. J. Roy. Meteor. Soc., 122, 929–944, 1996. Byun, D. and Schere, K. L.: Review of the governing equations, computational algorithms, and other components of the models-3 Community Multiscale Air Quality (CMAQ) modeling system, Appl. Mech. Rev., 59, 51–77, 2006. Byun, D. W., Moon, N. K., Jacob, D., and Park, R.: Regional transport study of air pollutants with linked global tropospheric chemistry and regional air quality models, 2nd ICAP Workshop, Research Triangle Park, NC, USA, 2004. Chin, M., Diehl, T., Ginoux, P., and Malm, W.: Intercontinental transport of pollution and dust aerosols: implications for regional air quality, Atmos. Chem. Phys., 7, 5501–5517, 2007. Collins, W. J., Derwent, R. G., Garnier, B., Johnson, C. E., Sanderson, M. G., and Stevenson, D. S.: Effect of stratosphere-troposphere exchange on the future tropospheric ozone trend, J. Geophys. Res., 108(D12), 8528, doi:10.1029/2002JD002617, 2003. Eder, B., and Yu, S. C.: A performance evaluation of the 2004 release of Models-3 CMAQ, Atmos. Environ., 40, 4811–4824, 2006. Fiore, A., Jacob, D. J., Liu, H., Yantosca, R. M., Fairlie, T. D., and Li, Q.: Variability in surface ozone background over the United States: Implications for air quality policy, J. Geophys. Res., 108(D24), 4787, doi:10.1029/2003JD003855, 2003. Fu, J. S., Jang, C. J., Streets, D. G., Li, Z. P., Kwok, R., Park, R., and Han, Z. W.: MICS-Asia II: Modeling gaseous pollutants and evaluating an advanced modeling system over East Asia, Atmos. Environ., 42, 3571–3583, 2008. Fusco, A. C. and Logan, J. A.: Analysis of 1970-1995 trends in tropospheric ozone at Northern Hemisphere midlatitudes with the GEOS-CHEM model, J. Geophys. Res., 108(D15), 4449, doi:10.1029/2002JD002742, 2003. Heald, C. L., Jacob, D. J., Fiore, A. M., Emmons, L. K., Gille, J. C., Deeter, M. N., Warner, J., Edwards, D. P., Crawford, J. H., Hamlin, A. J., Sachse, G. W., Browell, E. V., Avery, M. A., Vay, S. A., Westberg, D. J., Blake, D. R., Singh, H. B., Sandholm, S. T., Talbot, R. W., and Fuelberg, H. E.: Asian outflow and trans-Pacific transport of carbon monoxide and ozone pollution: An integrated satellite, aircraft, and model perspective, J. Geophys. Res., 108(D24), 4804, doi:10.1029/2003JD003507, 2003. Heald, C. L., Jacob, D. J., Park, R. J., Alexander, B., Fairlie, T. D., Yantosca, R. M., and Chu, D. A.: Trans-Pacific transport of Asian anthropogenic aerosols and its impact on surface air quality in the United States, J. Geophys. Res., 111, D14310, doi:10.1029/2005JD006847, 2006. Hoinka, K. P.: The tropopause: discovery, definition, and demarcation, Meteorol. Z., 6, 281–303, 1997. Holton, J. R., Haynes, P. H., McIntyre, M. E., Douglass, A. R., Rood, R. B., and Pfister, L.: Stratosphere-Troposphere Exchange, Rev. Geophys., 33, 403–439, 1995. Lam, Y. F., Fu, J. S., Gao, Y., Jacob, D., and Park, R.: Downscaling effects of GEOS-Chem as CMAQ Initial and Boundary Conditions: "Tropopause effect", The 7th Annual CMAS Conference, Chapel Hill, NC, USA, 2008. Li, Z., Fu, J. S., Jang, C., Wang, B., Mathur, R., Park, R., and Jacob, D.: Evaluation of GEOS-CHEM/CMAQ Interface Over China and US, The 2nd GEOS–Chem Users' Meeting, Cambridge, MA, USA, April, 2005. Liang, Q., Jaegle, L., Hudman, R. C., Turquety, S., Jacob, D. J., Avery, M. A., Browell, E. V., Sachse, G. W., Blake, D. R., Brune, W., Ren, X., Cohen, R. C., Dibb, J. E., Fried, A., Fuelberg, H., Porter, M., Heikes, B. G., Huey, G., Singh, H. B., and Wennberg, P. O.: Summertime influence of Asian pollution in the free troposphere over North America, J. Geophys. Res., 112, D12S11, doi:10.1029/2006JD007919, 2007. Lin, J. T., Wuebbles, D. J., and Liang, X. Z.: Effects of intercontinental transport on surface ozone over the United States: Present and future assessment with a global model, Geophys. Res. Lett., 35, L02805, doi:10.1029/2007GL031415, 2008. Liu, X., Chance, K., Sioris, C. E., Kurosu, T. P., Spurr, R. J. D., Martin, R. V., Fu, T. M., Logan, J. A., Jacob, D. J., Palmer, P. I., Newchurch, M. J., Megretskaia, I. A., and Chatfield, R. B.: First directly retrieved global distribution of tropospheric column ozone from GOME: Comparison with the GEOS-CHEM model, J. Geophys. Res., 111, D02308, doi:10.1029/2005JD006564, , 2006. Martin, R. V., Jacob, D. J., Logan, J. A., Bey, I., Yantosca, R. M., Staudt, A. C., Li, Q. B., Fiore, A. M., Duncan, B. N., Liu, H. Y., Ginoux, P., and Thouret, V.: Interpretation of TOMS observations of tropical tropospheric ozone with a global model and in situ observations, J. Geophys. Res., 107(D18), 4351, doi:10.1029/2001JD001480, 2002. Mathur, R., Lin, H. M., McKeen, S., Kang, D., and Wong, D.: Three-dimensional model studies of exchange processes in the troposphere: use of potential vorticity to specify aloft O₃ in regional models, The 7th Annual CMAS Conference, Chapel Hill, NC, USA, 2008. McPeters, R. D., Labow, G. J., and Logan, J. A.: Ozone climatological profiles for satellite retrieval algorithms, J. Geophys. Res., 112, D05308, doi:10.1029/2005JD006823, 2007. Morris, R. E., McNally, D. E., Tesche, T. W., Tonnesen, G., Boylan, J. W., and Brewer, P.: Preliminary evaluation of the community multiscale air, quality model for 2002 over the southeastern United States, J. Air Waste Manage., 55, 1694–1708, 2005. Morris, R. E., Koo, B., Tesche, T. W., Loomis, C., Stella, G., Tonnesen, G., and Wang, Z.: VISTAS Emissions and Air Quality Modeling - Phase I Task 6 Report: Modeling Protocol for the VISTAS Phase II Regional Haze Modeling, Novato, CA, USA, 2006. Newchurch, M. J., Ayoub, M. A., Oltmans, S., Johnson, B., and Schmidlin, F. J.: Vertical distribution of ozone at four sites in the United States, J. Geophys. Res., 108(D1), 4031, doi:10.1029/2002JD002059, 2003. Ordonez, C., Brunner, D., Staehelin, J., Hadjinicolaou, P., Pyle, J. A., Jonas, M., Wernli, H., and Prevot, A. S. H.: Strong influence of lowermost stratospheric ozone on lower tropospheric background ozone changes over Europe, Geophys. Res. Lett., 34, L07805, doi:10.1029/2006GL029113, 2007. Park, R. J., Jacob, D. J., Chin, M., and Martin, R. V.: Sources of carbonaceous aerosols over the United States and implications for natural visibility, J. Geophys. Res., 108(D12), 4355, doi:10.1029/2002JD003190, 2003. Park, R. J., Jacob, D. J., Field, B. D., Yantosca, R. M., and Chin, M.: Natural and transboundary pollution influences on sulfate-nitrate-ammonium aerosols in the United States: Implications for policy, J. Geophys. Res., 109, D15204, doi:10.1029/2003JD004473, 2004. Park, R. J., Jacob, D. J., Kumar, N., and Yantosca, R. M.: Regional visibility statistics in the United States: Natural and transboundary pollution influences, and implications for the Regional Haze Rule, Atmos. Environ., 40, 5405–5423, 2006. Perez, C., Jimenez, P., Jorba, O., Sicard, M., and Baldasano, J. M.: Influence of the PBL scheme on high-resolution photochemical simulations in an urban coastal area over the Western Mediterranean, Atmos. Environ., 40, 5274–5297, 2006. Song, C. K., Byun, D. W., Pierce, R. B., Alsaadi, J. A., Schaack, T. K., and Vukovich, F.: Downscale linkage of global model output for regional chemical transport modeling: Method and general performance, J. Geophys. Res., 113, D08308, doi:10.1029/2007JD008951, 2008. Stohl, A., Bonasoni, P., Cristofanelli, P., Collins, W., Feichter, J., Frank, A., Forster, C., Gerasopoulos, E., Gaggeler, H., James, P., Kentarchos, T., Kromp-Kolb, H., Kruger, B., Land, C., Meloen, J., Papayannis, A., Priller, A., Seibert, P., Sprenger, M., Roelofs, G. J., Scheel, H. E., Schnabel, C., Siegmund, P., Tobler, L., Trickl, T., Wernli, H., Wirth, V., Zanis, P., and Zerefos, C.: Stratosphere-troposphere exchange: A review, and what we have learned from STACCATO, J. Geophys. Res., 108(D12), 8516, doi:10.1029/2002JD002490, 2003. Streets, D. G., Fu, J. H. S., Jang, C. J., Hao, J. M., He, K. B., Tang, X. Y., Zhang, Y. H., Wang, Z. F., Li, Z. P., Zhang, Q., Wang, L. T., Wang, B. Y., and Yu, C.: Air quality during the 2008 Beijing Olympic Games, Atmos. Environ., 41, 480–492, 2007. Tagaris, E., Manomaiphiboon, K., Liao, K. J., Leung, L. R., Woo, J. H., He, S., Amar, P., and Russell, A. G.: Impacts of global climate change and emissions on regional ozone and fine particulate matter concentrations over the United States, J. Geophys. Res., 112, D14312, doi:10.1029/2006JD008262, 2007. Tang, Y. H., Carmichael, G. R., Thongboonchoo, N., Chai, T. F., Horowitz, L. W., Pierce, R. B., Al-Saadi, J. A., Pfister, G., Vukovich, J. M., Avery, M. A., Sachse, G. W., Ryerson, T. B., Holloway, J. S., Atlas, E. L., Flocke, F. M., Weber, R. J., Huey, L. G., Dibb, J. E., Streets, D. G., and Brune, W. H.: Influence of lateral and top boundary conditions on regional air quality prediction: A multiscale study coupling regional and global chemical transport models, J. Geophys. Res., 112, D10S18, doi:10.1029/2006JD007515, 2007. Tang, Y. H., Lee, P., Tsidulko, M., Huang, H. C., McQueen, J. T., DiMego, G. J., Emmons, L. K., Pierce, R. B., Thompson, A. M., Lin, H. M., Kang, D., Tong, D., Yu, S. C., Mathur, R., Pleim, J. E., Otte, T. L., Pouliot, G., Young, J. O., Schere, K. L., Davidson, P. M., and Stajner, I.: The impact of chemical lateral boundary conditions on CMAQ predictions of tropospheric ozone over the continental United States, Environ. Fluid Mech., 9(1), 43–58, doi:10.1007/s10652-008-9092-5, 2008. Tesche, T. W., Morris, R., Tonnesen, G., McNally, D., Boylan, J., and Brewer, P.: CMAQ/CAMx annual 2002 performance evaluation over the eastern US, Atmos. Environ., 40, 4906–4919, 2006. Vingarzan, R.: A review of surface ozone background levels and trends, Atmos. Environ., 38, 3431–3442, 2004. WMO, Atmospheric ozone, 1985: WMO Global Ozone Res. and Monit. Proj. Rep. 20, World Meteorological Organization (WMO), Geneva, Switzerland, 1986. Zangl, G., Gohm, A., and Obleitner, F.: The impact of the PBL scheme and the vertical distribution of model layers on simulations of Alpine foehn, Meteorology and Atmospheric Physics, 99, 105–128, 2008.