High Resolution Earth System Models at Decadal and Regional Scales: Seeking Sustainable Solutions for Rapidly Expanding Urban Areas Professor Alex Mahalov Wilhoit Foundation Dean's Distinguished Professor School of Mathematical and Statistical Sciences Arizona State University, U.S.

Abstract Challenges associated with a rapidly rising global population – an increase of more than 2.5 billion new urban inhabitants is projected by 2050, relative to 2011 – require high resolution physics-based, coupled, dynamic, and predictive capabilities that not only characterize current multi-scale environmental and socio-economic interactions but also enable the prediction of future impacts within growing cities. There is considerable evidence that models, predictions and mitigations strategies developed for temperate systems do not apply well to tropical/subtropical and arid climates. Feedback loops and nonlinear interactions interconnect physical and human processes. Understanding of emergent regional climate modifiers (urbanization, energy, agriculture) on decadal scales cannot be realized simply by studying these components in isolation. We discuss development of next-generation predictive modeling capabilities for linked agricultural and urban climate dynamics on decadal and regional scales. The advanced physics-based predictive analytics and statistical modeling tools are utilized to conduct ensemble-based regional hydro climate simulations, focusing on a set of rapidly urbanizing megapolitan areas across multiple climate zones. Novel computational methods to accelerate and improve accuracy of multi-scale nested models and data analytics are implemented to examine scale dependency of simulated outcomes. Scenario-based analysis and modeling techniques serve as a new paradigm for integrated studies of regional and urban climate systems on decadal timescales, which are critically important for policy makers. Strategic adaptation plans require development to increase production of agricultural commodities, maximize energy and land-use efficiency, enhance community engagement, reduce transportation costs while enhancing profitability, and mitigate adverse impacts such as the urban heat island effect and anthropogenic heating of the urban environment due to air conditioning. Development and refinement of physics based predictive modeling and assessment tools used at fine spatial resolution is necessary to effectively quantify co-benefits and reveal trade-offs prior to any strategy deployment. Several case studies will be presented. For example, changes to the world’s electrical power systems and grids threaten to require massive infrastructure investment and cost to power utilities, especially increasing population, built environment and electrical energy demands during peak summertime air conditioning loads, and mismatches between timing of supply and demand due to increases in renewable energy and/or large demands from new technologies. Brownouts and other grid failures are projected to become more common as peak demands approach grid capacities, with negative economic and public health consequences resulting. Meanwhile a financial barrier exists for the financing of grid improvements because utility revenues are proportional to total power sales, whereas utility costs are driven largely by capital and maintenance for the fixed infrastructure.

Pre-readings Salamanca, F., Georgescu, M., Mahalov, A., Moustaoui, M. and Wang, M. (2014). Anthropogenic heating of the urban environment due to air conditioning, Journal of Geophysical Research: Atmospheres, American Geophysical Union, 119(10), 5949–5965. 2014. http://onlinelibrary.wiley.com/doi/10.1002/2013JD021225/full Li, J., Georgescu, M., Hyde, P., Mahalov, A. and Moustaoui, M. (2015). Regional-scale transport of air pollutants: impacts of Southern California emissions on Phoenix ground-level ozone concentrations, Atmospheric Chemistry and Physics, 15, 9345–9360. http://www.atmos-chem-phys.net/15/9345/2015/acp-15-9345-2015.html Ruddell, B. L., Salamanca, F. and Mahalov, A. (2014). Reducing a semiarid city’s peak electrical demand using distributed cold thermal energy storage, Applied Energy, 134, 35–44. http://www.sciencedirect.com/science/article/pii/S0306261914007879

Urban Temperatures and Urban Heat Islands Professor James Voogt Associate Professor Department of Geography University of Western Ontario

Abstract

Cities provide a complex three-dimensional surface that is an interface to the atmosphere above and the substrate below. In the urban environment we can define surface temperatures, subsurface temperatures and air temperatures in both the urban canopy layer and urban boundary layer. How are each of these temperatures relevant to urban living? How do we observe and model these temperatures? What processes act to control the temperatures – recognizing that these processes are also the basis for mitigation and adaptation measures that may be applied to improve urban living conditions in a changing urban climate. When we compare urban temperatures with a non-urban reference we can define an urban heat island for each of the urban temperatures. These heat islands provide a measure of the environmental impact of cities. What is the conceptual basis for defining these heat islands and how are they operationalized? What processes are important for heat island formation and how do the heat islands vary in space and time? Finally, in the context of large scale climate change, how might urban temperatures and heat islands change in the future and how can we plan to monitor these changes?

Pre-readings

Lowry, W. P. (1977). Empirical estimation of urban effects on climate: a problem analysis. J. Appl. Meteorol., 16: 129–135. Oke, T. R. (1982). The energetic basis of the urban heat island, Quarterly Journal Royal Meteorological Society, 108: 1–24. Oke, T. R., Johnson, G. T., Steyn, D. G. and Watson, I. D. (1991). Simulation of surface urban heat islands under 'ideal' conditions at night. Part 2: Diagnosis of causation. Boundary-Layer Meteorology, 56, 339–358. McCarthy, M. P., Best, M. J., and Betts, R. A. (2010). Climate change in cities due to global warming and urban effects, Geophysical Research Letters 37, L09705. doi: 10.1029/2010GL042845.

Urban Climate and the Broader Challenge of Urban Sustainability: Definition, Measurement and Modelling Professor Darren Robinson Chair in Building and Urban Physics Department of Architecture and Built Environment University of Nottingham, U.K.

Abstract Sustainability has become a byword. Whilst it is understood that we are now mainly an urban species, that the overwhelming majority of economic activity and associated resource use takes place in cities, some surprisingly basic questions remain unanswered: How do we define city sustainability? How do we then measure it to determine how sustainable a city is? Which are the most effective strategies and policy measures to bring about positive change? How do we model them to evaluate their effectiveness? How do we then implement them? These are some of the questions currently being tackled by the Laboratory of Urban Complexity and Sustainability (LUCAS) at Nottingham. Positioned within this landscape, I will focus in this talk on the challenges we face in developing a platform for modelling the principle urban resource flows, in a sufficiently spatially resolved manner to support the testing of scenarios to minimise these flows (or some measure(s) of them) in the future. In this I will also explain the need to model the urban climate as well as urban radiative exchanges as well as candidate strategies for and complications in achieving this.

Pre-readings Robinson, D. (2011). Computer modelling for sustainable urban design: physical principles, methods and their applications. London: Earthscan (now Taylor & Francis). ISBN: 9781844076796. Arisona, S. M., Aschwanden, G., Halatsch, J. and Wonka, P. (2012). (eds.) Digital urban modelling and simulation. Heidelberg: Springer-Verlad. ISBN: 97836422975788. Batty, M. (2005). Cities and complexity. Cambridge: MIT Press. ISBN: 0262025833

Modeling Urban Environmental Risks Under Future Climate Change

Dr. Fei Chen Senior Scientist Research Applications Laboratory (RAL) National Center For Atmospheric Research (NCAR), U.S.

Abstract Today’s changing climate poses two formidable challenges: 1) the projected climate change by IPCC will lead to more frequent occurrences of heat waves, severe weather, and floods, and 2) the current trend of population increase and urban expansion is expected to continue. The combined effect of global climate change and rapid urban growth, accompanied with economic and industrial development, will inevitably make people living in cities more vulnerable to a number of the urban environmental problems. It is imperative to employ integrated modeling systems to assess such problems. First, we will introduce an NCAR effort, in collaboration with international research groups, in developing integrated urban modeling capabilities coupled to the Weather Research and Forecast (WRF) model (Chen et al., 2011a) as a community-modeling tool to address urban environmental issues. We will summarize the main features of the coupled WRF-Urban regional climate and weather prediction modeling system: 1) three methods with different degrees of freedom to parameterize urban surface processes, 2) coupling to fine-scale Computational Fluid Dynamic and Large-Eddy Simulation models for Transport and Dispersion (T&D) applications, and 3) procedures to incorporate high-resolution urban land-use, building morphology, and anthropogenic heating data. Also to be discussed are recent enhancements including improved urban hydrologic models, a new mosaic approach to treat land-use heterogeneity highly urbanized regions, and urban heat-island mitigation and urban-garden modeling. Second, we will discuss examples of applying WRF-Urban to address the following urban environmental risks under current and future climate conditions: 1) evolution of atmospheric boundary layer and atmospheric transport of accidental or intentional releases of toxic materials, 2) impacts of urbanization on mesoscale circulations, precipitation, and flood, 3) effects of urbanization on regional climate, air quality, and public health, and 4) mitigation strategies.

Pre-reading Oke, T. R. (1987). Boundary Layer Climates, Routledge, Boca Raton, Fla. 435 pp. Martilli, A., Clappier, A. and Rotach, M. W. (2002). An urban surface exchange parameterization for mesoscale models. Boundary-Layer Meteorology, 104: 261–304. Kusaka, H. and Kimura, F. (2004). Coupling a single-layer urban canopy model with a simple atmospheric model: impact on urban heat island simulation for an idealized case. Journal of the Meteorological Society of Japan, 82: 67–80. Liu, Y., Chen, F., Warner, T. and Basara, J. (2006). Verification of a Mesoscale Data-Assimilation and Forecasting System for the Oklahoma City Area During the Joint Urban 2003 Field Project. J. Appl. Meteorol., 45: 912–929. Lo, J.C.F., Lau, A.K.H., Chen, F., Fung, J.C.H. and Leung, K.K.M. (2007) Urban Modification in a Mesoscale Model and the Effects on the Local Circulation in the Pearl River Delta Region. J. Appl. Meteorol. Climatol., 46: 457–476. Jiang, X.Y., Wiedinmyer, C., Chen, F., Yang, Z.L. and Lo, J. C. F. (2008): Predicted Impacts of Climate and Land-Use Change on Surface Ozone in the Houston, Texas, Area. J. Geophys. Res., 113, D20312, doi:10.1029/2008JD009820. Lin, C-Y, Chen, F., Huang, J.C., Chen, W-C., Liou, Y.-A., Chen, W.-N. and Liu, Shaw-C. (2008). Urban Heat Island effect and its impact on boundary layer development and land-sea circulation over northern Taiwan, Atmospheric Environment, 42: 5635–5649. Miao, S., and Chen, F. (2008). Formation of horizontal convective rolls in urban areas. Atm. Res., 89: 298–304. 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. Bull. Amer. Meteor. Soc., 90: 1157–1168.

Miao, S., Chen, F., LeMone, M. A., Tewari, M., Li, Q. and Wang, Y. (2009). An Observational and Modeling Study of Characteristics of Urban Heat Island and Boundary Layer Structures in Beijing. J. Appl. Meteor. Climatol., 48: 484–501. Wang, X.M., Chen, F., Wu, Z., Zhang, M., Tewari, M., Guenther, A., Wiedinmyer, C. (2009). Impacts of weather conditions modified by urban expansion on surface ozone over the Pearl River Delta and Yangtze River Delta regions, China. Adv. Atmos. Sci., 26(5): 962–972. doi: 10.1007/s00376-009-8001-2. Zhang, C.-L., Chen, F., Miao, S.-G., Li, Q.-C., Xia, X.-A. and Xuan, C.-Y. (2009). Impacts of Urban Expansion and Future Green-Planting on Summer Precipitation in the Beijing Metropolitan Area. J. Geophys. Res., 114, D02116. doi: 10.1029/2008JD010328. Tewari, M., Kusaka, H., Chen, F., Coirier, W. J., Kim, S., Wyszogrodzki, A. A. and Warner, T. T. (2010) Impact of coupling a Microscale Computational Fluid Dynamics Model with a Mesoscale Model on Urban Scale Contaminant Transport and Dispersion. Atm. Res., 96: 656–664. Grimmond, C.S.B., et al. (2010). The International Urban Energy Balance Models Comparison Project: First results from Phase 1. J Appl. Meteorol. Climatol., 49: 1268–92. doi: 10.1175/2010JAMC2354.1. Chen, F., Kusaka, H., Bornstain, R., Ching, J., Grimmond, C. S. B., Grossman-Clarke, S., Loridan, T., Manning, K., Martilli, A., Miao, S., Sailor, D., Salamanca, F., Taha, H., Tewari, M., Wang, X., Wyszogrodzki, A. and Zhang, C. (2011a). 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. Chen, F., Miao, S., Tewari, M., Bao, J-W. and Kusaka, H. (2011b). A Numerical Study of Interactions Between Surface Forcing and Sea-Breeze Circulations and their Effects on Stagnant Winds in the Greater Houston Area. J. Geophys. Res. doi: 10.1029/2010JD015533. Miao, S., Chen, F., Li, Q. and Fan, S. (2011). Impacts of Urban Processes and Urbanization on Summer Precipitation: A Case Study of Heavy Rainfall in Beijing on 1 August 2006. J Appl. Meteorol. Climatol., 50 (4): 806-825 DOI: 10.1175/2010JAMC2513.1. Salamanca, F., Martilli, A., Tewari, M. and Chen, F. (2011): A study of the urban boundary layer using different urban parameterizations and high-resolution urban canopy parameters with WRF. J. Appl. Meteor. Climatol., 50: 1107–

1128.doi: 10.1175/2010JAMC2538.1. Zhang, D. L., Shou, Y. X., Dickerson, R. and Chen F. (2011). Impact of Upstream Urbanization on the Urban Heat Island Effects along the Washington-Baltimore Corridor. J Appl. Meteorol. Climatol., 50(10): 2012–2029. Niyogi, D., Pyle, P., Lei, M., Arya, S. P., Kishtawal, C. H., Shepherd, M., Chen, F. and Wolfe, B. (2011). Urban modification of thunderstorms - An Observational Storm Climatology and Model Case Study for the Indianapolis Urban Region J. Appl. Meteorol. Climatol., 50: 1129–1144. Kusaka, H., Chen, F., Tewari, M., Dudhia, J., Gill, D., Duda, M. G., Wang, W. and Miya, Y. (2012). Numerical Simulation of Urban Heat Island Effect by the WRF Model with 4-km Grid Increment: An Inter-Comparison Study between the Urban Canopy Model and Slab Model. J Met Soc Japan, 90B: 33–46. Chen, F., Bornstein, R., Grimmond, S., Li, J., Liang, X., Martilli, A., Miao, S., Voogt, J. and Wang, Y. (2012): Research priorities in observing and modeling urban weather and climate. Bull. Amer. Meteor. Soc., 93: 1725–1728. Wyszogrodzki, A., Miao, S., Chen, F. (2012) Evaluation of the coupling between mesoscale-WRF and LES-EULAG models for the fine-scale urban dispersion. Atm. Res., 118: 324–345. Li, D., Bou-Zeid, E., Barlage, M., Chen, F. and Smith, J. A. (2013). Development and evaluation of a mosaic approach in the WRF-Noah framework. J. Geophys. Res., 118, 11,918–11,935, doi:10.1002/2013JD020657.

Giovannini, L., Zardi, D., de Franceschi, M. and Chen, F. (2014). Numerical simulations of boundary-layer processes and urban-induced alterations in an Alpine valley. International Journal of Climatology, doi: 10.1002/joc.3750. Miao, S. and Chen, F. (2014). Enhanced modeling of latent heat flux from urban surfaces in the Noah/single-layer urban canopy coupled model. Science China Earth Sciences, doi: 10.1007/s11430-014-4829-0 Yates, D, Luna, B. Q., Rasmussen, R., Bratcher, D., Garrè, L., Chen, F., Tewari, M. and Friis-Hansen, P. (2014). Assessing climate change hazards to electric power infrastructure: A Sandy Case Study. IEEE Special Issue on Climate Change Adaptation. DOI:10.1109/MPE.2014.2331901. Yang, J., Wang, Z.-H, Chen, F., Miao, S., Tewari, M., Voogt, J. A. and Myint, S. (2015). Enhancing hydrologic modeling in the coupled WRF-urban modeling system. Boundary Layer Meteorol., 155: 87–109. DOI 10.1007/s10546-014-9991-6.

The Breathing City – Ventilation Processes from Building to City

Professor Janet Barlow Professor of Environmental Physics Department of Meteorology University of Reading, U.K.

Abstract

Fresh air is essential for our health and everyday well-being. Within urban areas, the air we breathe may be polluted and stale due to emissions of noxious pollutants, and a slow rate of exchange with cleaner air from outside the city due to lower wind speeds. Ventilation can be defined as the exchange of stale, polluted air for clean air, and it can happen on the scale of a person, room, building, neighbourhood or city. This talk will review the processes controlling ventilation at these different scales, and how the way we design our buildings and cities can improve ventilation rates, and help our cities to breathe more easily. Reference will be made to latest research findings and relevant policy or engineering guidelines. At the scale of people, the breathing zone will be described. At the scale of buildings, processes causing natural ventilation and typical mechanical ventilation systems will be described. Then consideration will be made of the neighbourhood surrounding a building, and how microclimate can affect ventilation rates within a building. Pollution dispersion mechanisms at the neighbourhood scale will be highlighted and how they can have a strong dependence on building morphology. Finally, at the scale of a city, urban boundary layer processes leading to ventilation will be described and how these are modified by surrounding hills, valleys and coastal flows.

Pre-readings

Awbi, H. (2003). Ventilation of Buildings. London: Taylor and Francis, pp328. Barlow, J. F. (2014). Progress in understanding and modelling the urban boundary layer. Urban Climate, 10: 216–240. Britter, R. E., & Hanna, S. R. (2003). Flow and dispersion in urban areas. Annu. Rev. Fluid Mech., 35(1): 469–496. Hiyama, K. and Kato, S. (2012). Chapter 6: Legal regulations for urban ventilation, in S. Kato and K. Hiyama (eds.), Ventilating Cities, Dordrecht: Springer, 135–149. Linden, P. (1999). The fluid mechanics of natural ventilation, Annu. Rev. Fluid Mech., 31: 201–238. Roth, M. (2000). Review of atmospheric turbulence over cities, Q. J. R. Meteorol. Soc., 126: 941–990.

Outdoor Thermal Comfort: Instruments, methods, standards and value ranges for the

tropics

Prof. Rohinton Emmanuel Professor of Sustainable Design and Construction Centre for Built Environment Asset Management Glasgow Caledonian University, U.K.

Abstract

Outdoor thermal comfort studies have proliferated globally in the last two decades and there is an upsurge in the tropics as well. Given the rapid rates of urbanization, the need for standardized measurement and reporting of thermal comfort information is all the more urgent in the tropics. Yet, wide variations in methods, instrumentation, measurement protocols, indices and reporting exist that seriously undermines inter-comparison and trend analysis. In this talk I will present evidence and explore potential causes for some of these discrepancies and explore the key issues that are often overlooked and/or misreported. Based on these, I will present some of the early works that some members of the International Association for Urban Climate (IAUC) have recently begun to ‘standardise’ outdoor thermal comfort studies and contextualise this to the rapidly urbanizing tropical cities. These will take the form of advice regarding the choice of measurement sites, type and positioning of instruments, appropriate methods to determine the mean radiant temperature, questionnaire design, suitable thermal comfort indices and advice on reporting.

Pre-readings

Chen L, Ng E. 2012. Outdoor thermal comfort and outdoor activities: a review of research in the past decade, Cities, 29 pp.

118–125

Johansson E, Thorsson S, Emmanuel R, Krüger E. 2014. Instruments and methods in outdoor thermal comfort studies – The

need for standardization, Urban Climate, 10(2), pp. 346-366

Rupp RF, Vásquez NG, Lamberts R, 2015. A review of human thermal comfort in the built environment, Energy and

Buildings, 105, pp 178-205

Thorsson S, Lindberg F, Eliasson I, Holmer B. 2007. Different methods for estimating the mean radiant temperature in an

outdoor urban setting. Int. J. Climatol. 27, 1893–1983

Thermal Counterpoint in Urban Climate

Professor Richard de Dear Professor Faculty of Architecture, Design and Planning The University of Sydney, Australia

Abstract

The mental state of thermal comfort is assumed to result from the thermo-physiological state of the body, which, in

turn, results from the delicate balance between heat generating process of metabolism on the one hand, and heat

exchanges with our thermal environment on the other. The “accepted wisdom” about thermal comfort is premised

on this deterministic chain of cause-and-effect relationships; physics -> physiology -> psychology. In these lectures we

will review some of the basic bodies of knowledge underpinning deterministic view of thermal comfort, including the

concepts of the body heat-balance, the physiological processes that manage that heat balance, then how they are all

represented in contemporary numerical models and thermal comfort indices.

The vast majority of research on the topic of thermal comfort has been performed in indoor settings, and the under-

researched topic of outdoor thermal comfort has been premised, to date, on the assumption that the deterministic

sequence described above; physics -> physiology -> psychology, applies equally well to the outdoor context as it does

to indoors. This assumption is implicit in all contemporary outdoor comfort models and indices such as OUT_SET, PET,

and UTCI which are direct derivatives of steady-state indoor comfort models.

After spending the first half of the lecture laying the foundations of contemporary outdoor thermal comfort tools, in

the second half of the lecture we start dismantling it because of its inadequacy at representing how the outdoor

thermal environment truly feels. The missing phenomenological dimension in contemporary thermal comfort tools is

affect i.e. whether we like or dislike the incoming thermal sensory information about our body’s thermal state. Steady-

state comfort models and indices presume that the thermally neutral mental state in which we feel neither warm nor

cool, is indeed the ideal or preferred state. This assumption is questionable - neutral does not always equal ideal, and

thermal stimulation from the environment can, in certain circumstances, be a source of delight (far from

neutrality). Our experience of the thermal environment, particularly in outdoor meteorological contexts, is rarely in

steady state, and very rarely isothermal. These temporal dynamics and spatial variations in the outdoor microclimates

underpin our feelings of thermal pleasure (or displeasure) and the mechanisms are summarised in a physiological

hypothesis called alliesthesia. Alliesthesia explains the physiological role of thermal pleasure and my lectures

conclude with a discussion of how alliesthesia can bring us to a deeper, more nuanced understanding of the way

humans perceive outdoor microclimates than possible with contemporary models of steady-state, isothermal heat–

balance comfort.

Pre-readings

ASHRAE, I. (2013). CHAPTER 8. ASHRAE HANDBOOK of Fundamentals (ASHRAE Inc., Atlanta GA). Cabanac, M. (1971). Physiological role of pleasure. Science, 173(4002): 1103-1107. de Dear, R. (2011). Revisiting an old hypothesis of human thermal perception: alliesthesia. Building Research & Information, 39(2): 108-117. de Dear, R., et al. (2013). "Progress in thermal comfort research over the last twenty years." Indoor air, 23(6): 442-461. Fanger, P. O. (1970). Thermal comfort. Analysis and applications in environmental engineering. Lyngby: Technical Press of Denmark.

Gagge, A. P. (1971). An effective temperature scale based on a simple model of human physiological regulatory response. ASHRAE Trans. 77: 247-262. Gagge, A. P. et al. (1986). A standard predictive index of human response to the thermal environment. ASHRAE Trans, 92 2B, 709-731. Höppe, P. (1999). The physiological equivalent temperature – A universal index for the biometeorological assessment of the thermal environment. International journal of biometeorology, 43(2): 71-75. Jendritzky, G. et al. (2012). UTCI—Why another thermal index? International journal of biometeorology, 56(3): 421-428. Mayer, H. and Höppe, P. (1987). Thermal comfort of man in different urban environments. Theoretical and Applied Climatology, 38(1): 43-49. Nishi, Y. and Gagge, A. (1977). Effective temperature scale useful for hypo-and hyperbaric environments. Aviation, space, and environmental medicine, 48(2): 97-107. Pickup, J. and de Dear, R. (2000). An outdoor thermal comfort index (OUT_SET*)-part I-the model and its assumptions. Biometeorology and urban climatology at the turn of the millenium. Selected papers from the

Conference ICB-ICUC.

The Effect of Climate Change on Urban Climate and Built Environment

Professor Ryozo Ooka Professor Institute of Industrial Science The University of Tokyo, Japan

Abstract Climate change phenomena, such as global warming and urban heat island effects, cause serious problems. Mitigation and adaptation are the two approaches used when dealing with global warming. The adaptation of building designs with regard to climate change is needed to continue building comfortable indoor environments in the future. During the design process, energy simulations are often used to evaluate the indoor thermal environment and energy consumption of buildings. In these simulations, it is common to use regional weather data known as design weather data, which is usually based on current or past weather events. However, most buildings have been used for several decades during which climate conditions have gradually changed. Therefore, the development of weather data for the future and the assessment of climate change impact on buildings have become very important for both mitigation and adaptation. In this study, we attempt to construct near-future design weather data for architectural design using numerical meteorological models. Climate data that is predicted by Global Climate Models (GCMs) is available. The future weather data produced by this method is expected to exhibit global climate change and local phenomena such as urban heat islands. We employ the Model for Interdisciplinary Research on Climate version 4 (MIROC4h) as the GCM and the Weather Research and Forecasting (WRF) model as the RCM. Correcting the selected weather data with observations to reduce bias of both regional climate models (RCMs) and global climate models (GCMs), we constructed a prototype of the near-future design weather data of the 2030s. We conducted building energy simulations using the prototype of design weather data to assess the impact of climate change on energy consumption of a two-story detached house in Tokyo. Under these conditions, total sensible heat load in August increased 26%, and the latent heat load increased 10%.

Evaluation of the Effects of Greening and Highly Reflective Materials from Three Perspective –Mitigation of Global Warming, Mitigation of UHIs, and Adaptation to Urban Warming Professor Akashi Mochida Professor, Department of Architecture and Building Science, Graduate School of Engineering, Tohoku University, Japan

Abstract In recent years, various countermeasures against urban warming have been developed. Most studies that compared the effects of several countermeasures techniques were aimed towards a single perspective: either that of energy savings, the suppression of effluent sensible heat, or the improvement of the thermal environment in pedestrian spaces. However, these aims often conflict with one another. Thus, great difficulties still remain when policymakers and urban planners attempt to select proper countermeasure techniques. To overcome the difficulties, the purposes of countermeasures should be considered. Firstly, there are two aspects to these countermeasures: mitigation and adaptation. Secondly, ongoing urban warming is being caused by both global warming and the creation of urban heat islands (UHIs). Global warming is caused by the rising concentration of greenhouse gases, whereas a UHI is caused by a modification in land-use from a natural environment into a built environment with the intensive energy consumption resulting in anthropogenic heat release. Thus, the energy savings resulting in CO2 emission reductions are essential for mitigating global warming, and the suppression of effluent sensible heat from urban surfaces is essential for mitigating UHIs. Different countermeasures are needed to mitigate these two phenomena, global warming and UHIs, and to adapt to urban warming. However, the distinctions between countermeasures used (1) to mitigate global warming, (2) to mitigate UHIs, and (3) to adapt to urban warming remain vague. To assess the effects of countermeasures used to mitigate global warming, mitigate UHIs, and adapt to urban warming simultaneously, a new assessment system was proposed. In this lecture, the results of two simulations are reported: one is the evaluation of the effects of greening and highly reflective material applied to vertical walls and another is the evaluation of the effects of roadside trees in an actual urban area.

Pre-readings

Yumino, S., Uchida, T., Sasaki, K., Kobayashi, H. and Mochida A. (2015). Total assessment for various environmentally conscious techniques from three perspectives: mitigation of global warming, mitigation of UHIs, and adaptation to urban warming, Sustainable cities and society (accepted). http://dx.doi.org/10.1016/j.scs.2015.05.010 Yumino, S., Uchida, T., Mochida, A., Kobayashi, H. and Sasaki, K. (2015). Evaluation of greening and highly reflective materials from three perspectives, Proceedings of 9th International Conference on Urban Climate jointly with 12th Symposium on the Urban Environment. https://www.conftool.com/icuc9/index.php?page=browseSessions&form_session=113#paperID4

Evaluation of the health hazard risk in urban pedestrian space based on the total analysis

of mesoscale and microscale climates

Professor Akashi Mochida

Professor, Department of Architecture and Building Science,

Graduate School of Engineering, Tohoku University, Japan

Abstract Health hazards of extremely hot summer conditions (e.g., heatstroke) have increased rapidly in recent years. In this study, the increase in the number of heatstroke patients caused by extremely hot summer conditions was regarded as a disaster, and a new evaluation method for outdoor thermal environment based on the concept of risk evaluation was developed. The thermal environment inside an urban area is formed by a combined influence of weather conditions above the urban area and urban structure, e.g., the building shape and arrangement, the green cover ratio, the intensity of anthropogenic heat release, etc. Inside an urban area, the thermal environment is often severer than that above it owing to the effect of the urban structure. In other words, inappropriate urban planning and building design can amplify threats caused by weather conditions. In this study, to distinguish between hazards that cannot be controlled by humans and those that can be controlled by modification of urban structures, “natural hazard” and “actual hazard” were defined, respectively. Specifically, a natural hazard is an uncontrollable hazard, which can be estimated from weather conditions above an urban area, while an actual hazard is a hazard that pedestrians are exposed to because of the thermal environment inside the urban area. A “hazard increment” is a component of hazard and is the increase in threat caused by inappropriate urban planning and building design. An actual hazard is a combination of a natural hazard and hazard increment. The spatial distribution of actual hazard values inside urban areas and the health risk value were estimated from the results of a microscale climate analysis using the result of a mesoscale climate analysis as boundary conditions for the central region of Sendai. Roadside trees reduced the health risk by providing shade under the conditions assumed in this study.

Pre-readings

Yumino, S., Mochida, A., Hamada, N. and Ohno S. (2015). Method for evaluating the health risk in urban pedestrian space in extremely hot summer conditions based on the total analysis of mesoscale and microscale climates, Proceedings of 9th International Conference on Urban Climate jointly with 12th Symposium on the Urban Environment. https://www.conftool.com/icuc9/index.php?page=browseSessions&form_session=38#paperID440

Designing responsively: Pedestrian thermal stress in hotter and drier cities

Professor David Pearlmutter

Associate Professor and Department Chairperson

Bona Terra Department of Man in the Desert

The Swiss Institute for Dryland Environmental & Energy Research

The Jacob Blaustein Institute for Desert Research

Ben Gurion University of the Negev, Isarel

Abstract Cities are susceptible to warming due to the compound effects of local heat islands and global climate trends. The latter may also introduce drier conditions in regions of the world which have large urban populations, and these hot-dry conditions can have serious implications for the thermal comfort and well-being of pedestrians in urban open spaces. This can in turn amplify their reliance on air-conditioned buildings and vehicles, further increasing the emissions which contribute to local and global warming in the first place. In this session we will draw upon research and real-world experience from urban areas in arid regions, to examine how the thermal stress encountered by dwellers of hot-arid cities can be mitigated through urban design. In the first part we will review the microclimatic processes which contribute to physiological stress and the perception of thermal discomfort, and in the second part we will look at design strategies – in principle and in practice – for improving the thermal environment of urban spaces. 1. Understanding pedestrian thermal stress

Thermal exchanges between the human body and the urban environment through radiation, convection and evaporation, and their quantification using indices of thermal stress

Influences of the urban environment on direct and indirect solar radiation, surface temperature and long-wave radiation, wind speed, air temperature and humidity

The relation between biophysical stress and subjective thermal sensation, considering physical activity and behavioral variables

2. Urban design strategies for enhancing pedestrian thermal comfort

The role of three-dimensional urban geometry (canyon aspect ratio/sky view factor, axis orientation)

The "efficient" use of trees and ground-cover vegetation for moderating thermal stress in hot-arid cities, weighing the benefits obtained in terms of cooling vs. the costs in terms of the irrigation water required

Examples of actual climate-responsive urban design projects

Pre-readings Erell, E., Pearlmutter, D. and Williamson, T. (2011). Urban Microclimate: Designing the Spaces between Buildings. London: Earthscan.

Chapter 1 – Scales of Climatic Study (pp. 15-26)

Chapter 5 – The Energy Balance of a Human Being in an Urban Space (pp.109-124) Chapter 8 – Microclimate Design Strategies in Urban Space (pp. 145-163)