Development, evaluation, and application of mesoscale meteorological-models (WRF, MM5, and RAMS) to urban environmental problems Professor Robert Bornstein Highly urbanized mesoscale meterological models have been applied at SJSU to studies of urban climate, weather, climate change, and air quality in a variety of cities, e.g., Houston, New York, San Francisco, Atlanta, Los Angeles, and Jerusalem. Urbanization of the surface energy balance equations; analytical surface boundary layer (SBL) formulations; and the prognostic finite-differenced momentum, energy, and TKE equations leads to more accurate simulations of urban: heat islands, planetary boundary layer transport characteristics, impacts on precipitation processes, air quality, and climate change patterns. This presentation reviews the development of these urbanization schemes, as well as their: evaluation against observations; linkages with larger scale models to provide initial and boundary conditions; and still existing problems in their formulation, use, and initialization. A procedure is presented that describes a method to sequentially evaluate their inputs and outputs to produce more accurate simulation results. The above points are illustrated with results from simulations in coastal zones of urban impacts on winter cyclone precipitation, as well as on summer: UHIs, urban wind flow patterns, thunderstorms, ozone transport patterns, and decadal temperature-trends.
Fine scale meteorology and air quality models as urban forecasting, planning and assessment tools Dr. Jason Ching Weather and air quality models are powerful tools for air quality forecasting, planning and assessment applications in urban areas especially when employed at increasingly finer grid meshes. In this regard, we review current understandings of grid size dependent model issues, emerging new urban canopy physics parameterizations and its specialized data inputs for fine grid mesh mesoscale and urban scale simulations with illustrations from sensitivity study simulations based on the WRF and CMAQ modeling systems as applied to the Houston Texas area. Also, we note from observations the presence and persistence of quasi-stationary mesoscale structures of mixed layer origins for weakly forced flows, a situation that provide an important context for examining model requirements and performance for urban applications. In addition and to take advantage of increasing experiences and capabilities to model at fine scales, a conceptual framework is described that can provide sub-grid scale weather and pollutant concentration distributions (or parameterizations) for coarser grid operational meteorological and air quality modeling applications. References Byun, D.W., and J.K.S. Ching (Eds.): Science algorithms of the EPA Models-3 Community Multiscale Air Quality (CMAQ) modeling system. EPA-600/R-99/030, National Exposure Research Laboratory, U.S., Environmental Protection Agency. Research Triangle Park, NC (1999). Byun D., and Schere, K.L., 2006: Review of the governing equations, computational algorithms and other components of the Models-3 Community Multiscale Air Quality (CMAQ) modeling system. Applied Mechanics Reviews (59) 51-57. Chen F, Kusaka H, Bornstein R, Ching J, Grimmond CSB, Grossman-Clarke S, Loridan T, Manning KW, Martilli A, Miao S, Sailor D, Salamanca FP, Taha H, Tewari M, Wang X, Wyszogrodzki A.A, Zhang C. 2011. The integrated WRF/urban modeling system: development, evaluation, and applications to urban environmental problems. International Journal of Climatology 31: 273 288. DOI: 10.1002/joc.2158. Ching, Jason, J. Herwehe and J. Swall, 2006b: On joint deterministic grid modeling and sub-grid Variability conceptual framework for model evaluation, Atmospheric Environment, 40 (2006) 4935-4945. Ching, J., Brown, M., Burian, S., Chen, F., Cionco, R., Hanna, A., Hultgren, T., McPherson, T., Sailor, D., Taha, H., and Williams, D., 2009. National urban database and access portal tool, NUDAPT. Bulletin of the American Meteorological Society (BAMS) doi:10.1175/2009bams2675.1 Dupont S., Otte T., Ching J., 2004. Simulation of meteorological fields within and above urban and rural canopies with a mesoscale model (MM5). Boundary-Layer Meteorology 113, 111-158. Martilli, A., A. Clappier and M.W. Rotach, 2002: An urban surface exchange parameterization for mesoscale models. Boundary-Layer Meteorol., 104, 261-304. Taha, H., 2008a. Meso-urban meteorological and photo-chemical modeling of heat island mitigation. Atmospheric Environment, 42, 8795-8809. doi:10.1016/j.atmosenv.2008.06.036 http://www.wrf-model.org/index.php
2-way Coupled WRF-CMAQ Modeling for Hemispheric to Mesoscale to Urban Scale Air Quality Modeling Professor Jonathan Pleim Interactions of chemical, physical, and dynamical processes are most faithfully represented using coupled meteorology and chemical transport modeling systems such as the new 2-way coupled meteorology and air quality model composed of the Weather Research and Forecasting (WRF) model and the Community Multiscale Air Quality (CMAQ) model being developed and tested at the USEPA. Advantages of the coupled model over traditional sequential meteorology and air quality model systems include: 1) more efficient frequent data exchange for high resolution (down to 1 km grid cell size) simulations that are needed for urban-scale modeling studies, 2) includes feedback of gases and aerosols from CMAQ to WRF where they can affect radiation and microphysics processes, 3) allows for more integrated treatment of chemical and physical processes. The 2-way coupled WRF-CMAQ system has been tested for a hemispheric modeling domain, where aerosol direct effects on SW radiation and resultant effects on air temperature and PBL height over large areas of South and East Asia have been demonstrated. Mesoscale modeling of an outbreak of wildfires in California similarly demonstrated large effects of aerosol loads on meteorology and air pollution concentrations. Recently, the 2-way coupled WRF-CMAQ system has been applied at high resolution for the Houston, TX area where the impacts of both direct and indirect aerosol effects are being studied.
Modelling Urban Air Quality using the Street Scale Resolution Atmospheric Dispersion Model ADMS-Urban Dr. David Caruthers The urban version of the atmospheric dispersion modelling system (ADMS) comprises a Gaussian type model for local impacts nested within a grid based model for urban scale or regional impacts. In addition to point and area sources the model explicitly models transport sources including the impacts of road traffic, rail, shipping and aircraft/airports. Features of the model specific for the urban and built environment include allowance for street canyons and other complex features such as cuttings and flyovers, and the impact of the urban environment on the atmospheric boundary layer. The presentation will include a detailed description of the model features together with its application to a diverse range of urban locations across the world including London and Beijing. It will also include recent studies in which ADMS is nested within numerical models such as CMAQ. References Carruthers D, McHugh C, Jackson M and Johnson K, (2011): Developments in ADMS Airport to take account of near field dispersion and applications to Heathrow Airport. International Journal of Environment and Pollution, vol. 44, No.1/2/3/4 pp. 332 341, DOI: 10.1504/ijep.2011.038434. Athanassiadou A, Baker J, Carruthers DJ, Collins W, Girnary S, Hassel D, Hort M, Johnson C, Johnson K, Jones R, Thomson D, Trought N and Witham C,(2010): An assessment of the impact of climate change on air quality at two UK sites.atmospheric Environment, vol. 44, issue 15, pp. 1877 1886, DOI: 10.1016/jatmosenv.2010.02.024. Stocker JR, Carruthers DJ, Ellis K and Rogers L,(2005):The non-linear relationship between road traffic emissions and pollutant concentrations.10 th International Conference on Harmonisation, Crete, Greece, October 2005. See http://www.harmo.org/ Carruthers DJ, Johnson KL, Stidworthy AL and Blair JW,(2004): Modelling air quality scenarios in London, are the EU limit values for NO 2 and PM 10 achievable?9 th International Conference on Harmonisation, Garmisch-Partenkirchen, Germany, June 2004. See http://www.harmo.org/ Hunt,J C R, D J Carruthers, R E Britter, N C Daish Dispersion from Accidental Releases in Urban Areas (2002): A report prepared for ADMLC,Cambridge Environmental Consultants. http://www.admlc.org.uk/documents/admlc20023_000.pdf Colvile RN, Woodfield NK, Carruthers DJ, Fisher BEA, Rickard A, Neville S and Hughes A,(2002): Uncertainty in dispersion modelling and urban air quality mapping. Environmental Science & Policy, vol. 5, issue 3, pp. 207-220
Impact of Global Climate Change on Urban Air Constituents Professor Wilhelm Kuttler On the basis of projections made by the IPCC (2007), global climate change, especially in large cities, will lead to higher temperatures, more frequent heat waves and rising CO2 concentrations in comparison with the undeveloped surrounding countryside. The effects of these factors on the concentration of selected air constituents which occur in higher concentrations especially in cities is investigated taking central European data as an example. The analysis is conducted for the trace substances ozone, nitrogen dioxide, particulate matter and pollen, of which certain types can cause allergies among human sufferers. It is shown that both higher temperatures and CO2 concentration have an impact on concentration distribution. Ozone and pollen concentrations increase in a warmer climate, while there is no clear relationship between higher temperatures and nitrogen dioxide and particulate matter concentrations. The reasons for the different behaviour of trace substances with reference to temperature are discussed. The target of this lecture is to provide an overview of the influence of increasing global temperature on the distribution and concentration of both gaseous/solid air constituents and pollen in the urban scale which harm directly or indirectly human health. References: JACOB, D. J. and D. A. WINNER (2009): Effect of climate change on air quality.- Atm. Environment 43, 51-63 KUTTLER, W. (2008): The Urban Climate - Basic and Applied Aspects. In: MARZLUFF, J.M., E. SHULENBERGER,, W. ENDLICHER, M. ALBERTI, G. BRADLEY, C. RYAN, U. SIMON, C. ZUMBRUNNEN (editors.): Urban Ecology - An International Perspective on the Interaction between Humans and Nature, Springer, pp. 233-248. KUTTLER, W. (2011): Klimawandel im urbanen Bereich, Teil 1, Wirkungen; Climate change in urban areas, Part 1, Effects. - In: Environmental Sciences Europe (ESEU), Springer open, DOI: 10.1186/2190-4715-23-11, S. 1-12. KUTTLER, W. (2011): Klimawandel im urbanen Bereich, Teil 2, Maßnahmen; Climate change in urban areas, Part 2, Measures. - In: Environmental Sciences Europe (ESEU), Springer open, Doi: 10.1186/2190-4715-23-21, S. 1-15. ZISKA, L.H.; GEBHARD, D.E.; FRENZ, D.A.; FAULKNER, S., SINGE, B.D.; STRAKA, J.G. (2003): Cities as harbingers of climate change: common ragweed, urbanisation and public health.- Journal of Allergy and Clinical Immunology, 111, 290-295
Dispersion in Urban Areas Professor Stephen Belcher Issues of urban air quality and response to emergencies demand methods for predicting dispersion of airborne material in urban areas. In this lecture I will review the special processes that control dispersion in urban areas. I will then show how the main features of the dispersion can be captured using a simplified "network model". The dispersion is treated as moving through the network of streets whilst being exchanged with the atmospheric boundary layer above. This approach is shown to capture the main processes at work.