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Lectures course Meteorology applied to Meteorology applied to Urban Air Pollution Urban Air Pollution Problems ProblemsAlexander Baklanov, Danish Meteorological Institute Young Scientists School on Computational Information Technologies for Environmental Sciences: “CITES-2005” Novosibirsk, Russia, March 13-19, 2005

Meteorology applied to Urban Air Pollution Problems Lectures course “Meteorology applied to Urban Air Pollution Problems” Alexander Baklanov, Danish Meteorological.

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Meteorology applied to Urban Air Pollution Problems Lectures course Meteorology applied to Urban Air Pollution Problems Alexander Baklanov, Danish Meteorological Institute Young Scientists School on Computational Information Technologies for Environmental Sciences: CITES-2005 Novosibirsk, Russia, March 13-19, 2005 Slide 2 Meteorology applied to Urban Air Pollution Problems: Lecture schedule . 17 2005 11:00 13:00 (/ ) 2. Meteorology applied to Urban Air Pollution Problems. Alexander Baklanov (Danish Meteorological Institute, Denmark) 13:00 14:30 14:30 15:30 - 3. Meteorology applied to Urban Air Pollution Problems. Alexander Baklanov (Danish Meteorological Institute, Denmark) 15:30 - ( , ) . 18 2005 9:00 13:15 (/ ) 1. Meteorology applied to Urban Air Pollution Problems. Alexander Baklanov (Danish Meteorological Institute, Denmark) 11:00 11:15 - 2. Meteorology applied to Urban Air Pollution Problems. Alexander Baklanov (Danish Meteorological Institute, Denmark) 13:15 14:30 Slide 3 Structure of the Lectures I.Introduction to European research (COST Actions 710, 715, 728, 732, SATURN/EUROTRAC, CLEAR cluster, ACCENT, etc.) II.Structure of the urban boundary layer III.Modification of flow and turbulence structure over urban areas IV.The surface energy balance in urban areas V.The mixing height and inversions in urban areas VI.Evaluation and analysis of European peak pollution episodes VII.European urban experiments (Copenhagen, ESCOMPTE, BUBBLE, etc.) VIII.Preparation of meteorological input data for urban air pollution models IX.Integrated modelling : Forecasting Urban Meteorology, Air Pollution and Population EXposure (FUMAPEX) and COST 728 X.Summary of achievements, gaps in knowledge, recommendations for further research Slide 4 Why Urban Meteorology Now? Technological Advances Remote sensing and other platforms Computer models Homeland Security Atmospheric Transport and Diffusion (ATD) models Health and Safety High impact weather Air quality Slide 5 Why do we have to consider the urban effects? What kind of effects? Slide 6 Local-scale inhomogeneties, sharp changes of roughness and heat fluxes, Wind velocity reduce effect due to buildings, Redistribution of eddies due to buildings, large => small, Trapping of radiation in street canyons, Effect of urban soil structure, diffusivities heat and water vapour, Anthropogenic heat fluxes, urban heat island, Internal urban boundary layers (IBL), urban Mixing Height, Effects of pollutants (aerosols) on urban meteorology and climate, Urban effects on clouds, precipitation and thunderstorms. Urban BL features: Slide 7 At small scale in the urban canopy, the built environment can induce negative effects: A city can be considered as a protect area for meso scale atmospheric events : Urban heat island has a positive influence in the winter outdoor thermal comfort and the energy consumption Urban roughness mitigates wind speed actions on tall buildings above the mean roof level But over speed area around buildings low diffusion of pollutants in street canyon Lack of ventilation for indoor and outdoor comfort Slide 8 Buildings located downwind of small roughness (sea and open country) had more damages on structure Wind effects on structure urban suburbs Open country sea % of damages Example: effects of storm Lothar (1999) Slide 9 The Urban System (EU 5FP City of Tomorrow) Interactions between the city, human environment and biophysical environment INPUTS EnergyMoney Food Information WaterRaw Materials Manufactured goods HUMANTHE CITYBIOPHYSICALENVIRONMENT PeoplePhysical StructureAtmosphere & Energy Flows EthnicityBuilding TypeHydrological Cycle PoliticsLayoutSoils, Vegetation, Fauna TechnologyGeology & Landforms OUTPUTS WastesEmployment Liquids Wealth SolidsManufactured Goods GasesDegraded Energy LINKS TOUrban Systems OTHERRural Systems Regions Transport Communication From Bridgman et al. (1996) Slide 10 Introduction to European research COST Actions 710, 715, 728, 732, SATURN/EUROTRAC/TRAPOS, CLEAR cluster, FUMAPEX project, ACCENT Network of Excellence, ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ WMO GURME project US EPA/NOAA projects Slide 11 Harmonisation in the pre-processing of meteorological data for dispersion models COST710 In the framework of COST, there has been an international action, COST 710, aimed at Harmonisation in the pre-processing of meteorological data for dispersion models. COST 710 has been followed by a related action, COST 715, concerning Urban Meteorology applied to Air Pollution Problems. A somewhat related action, COST 732, will be carried out from 2005 onwards. COST 732 is entitled Quality Assurance and Improvement of Microscale Meteorological Models. Meteorology applied to Urban Air Pollution Problems - COST 715 In the framework of COST, an international action has been conducted aimed at increasing knowledge of, and the accessibility to, the main meteorological parameters which determine urban pollution levels. The action was designated initiated COST 715. COST 715 follows a previous action, COST 710. COST - European Co-operation in the field of Scientific and Technical Research ( Domain: Meteorology Slide 12 Working Group 1:Urban wind field Working Group 2: Energy Budget and the Mixing height in Urban Areas Working Group 3: Meteorology during peak pollution episodes Working Group 4: Input Data for Urban Air Pollution Models Meteorology applied to Urban Air Pollution Problems - COST 715 (1998 2004) Slide 13 Working Group 1: Urban wind field Goals Review and evaluate methods to describe and parameterise the wind field over urban areas from routine meteorological observations: near-surface conditions (roughness sublayer) profile throughout the UBL possibly: distinction between different locations within a city recommendations on what /how Met. Services (and others) should measure in urban areas Methods Review existing methods (theories) for the specific goals above identify existing data sets for the specific goals above identify new data sets develop general semi-empirical relationships for the description of the UWF and related parameters Plans In the longer term, seeking new directions for developing a theory for the urban wind profile Evaluation of the role of alternative tools such as numerical models or remote sensing techniques Slide 14 Working Group 2: The Surface Energy Budget and the Mixing height in Urban Areas Background Urban pollution meteorology is characterised by a number of fundamental parameters and their evolution in time, which all have specific problems as to their monitoring, representativeness, parameterisation and modelling. Within COST-715, WG2 addresses the specific problems in describing the surface energy balance and the mixing height. The surface energy balance and the surface temperature and heat fluxes determine the hydrostatic stability conditions in the lower atmosphere and regulate its strength for mixing pollutants, the mixing height parameter determines the available volume for pollutants mixing. The activities of WG2: To review theoretical concepts of the structure of the urban boundary layer. To review and assess pre-processors, schemes and models for determining the mixing height, the surface energy budget and the stability that are available to the participants. Cases of strong stability and/or windless conditions are of special interest. To review theoretical models together with available field measurements and LES for calculation of the minimum friction velocity and the heat transfer coefficient. Conditions of shear free convection over high roughness are of main importance To identify and review suitable data sets within and outside the group that could be used to test and validate the pre- processors and models. To carry out intercomparisons and to summarise comparisons of different schemes against each other and against data under specific conditions. To assess the influence of the model outputs of certain specific effects such as complex topography, strong heterogeneity, slope effects and canopy trapping on radiative fluxes. To assess the suitability of remote sensing tools to estimate canopy characteristics and surface fluxes. To provide recommendations for the improvement of existing pre-processors and models and for the development of new schemes. To provide recommendations for planning and conducting field campaigns in order to fill the important existing gaps for empirical data of key parameters for urban air pollution. To promote co-ordination of related activities in Europe of presently scattered works, objectives, and responsibilities. Slide 15 Working Group 3: Meteorology during peak pollution episodes During air pollution episodes pollutant concentrations are highest, and the related adverse health impact on the public should therefore be reliably evaluated. The meteorological conditions prevailing in the course of episodes are at the same time commonly the most difficult to model with the computing tools presently available. European Union nevertheless requires practical measures to be taken, if air quality limit values are exceeded. Slide 16 Coordinator: Prof. Ranjeet S Sokhi Atmospheric Science Research Group (ASRG) University of Hertfordshire, UK Scientific Officer: Viorel Vulturescu European Commission, DG Research Launched: December 2002 CLEAR Cluster of European Air Quality Research Slide 17 Aim of CLEAR Threefold aim: To improve our scientific understanding of atmospheric processes, composition and pollution variabilities on local to regional scales To provide next generation tools for end users and stakeholders for managing air pollution and responding to its impact To help create a critical mass of expertise and ambition to address future research needs in the areas of air pollution, its impact and response strategies. Slide 18 Eleven Participating Projects FP5, EESD, City of Tomorrow ATREUS (Coordinator: Dr Agis Papadopoulos, University of Thessaloniki) Human Potential Research network - Advanced Tools for Rational Energy Use towards Sustainability with emphasis on microclimatic issues in urban applications OSCAR (Coordinator: Professor Ranjeet S Sokhi, University of Hertfordshire) -Optimised Expert System for Conducting Environmental Assessment of Urban Road Traffic FUMAPEX (Coordinator: Dr Alexander Baklanov, DMI) Integrated Systems for Forecasting Urban Meteorology, Air Pollution and Population Exposure ISHTAR (Prof Emanuele Negrenti, ENEA) - Integrated Software for Health, Transport efficiency and Artistic heritage Recovery Slide 19 Eleven Participating Projects FP5, EESD, City of Tomorrow SAPPHIRE (Coordinator: Dr Stuart Harrad, University of Birmingham) - Source Apportionment of Airborne Particulate Matter and Polycyclic Aromatic Hydrocarbons in Urban Regions of Europe URBAN AEROSOL (Professor Mihalis Lazaridis, Technical University of Crete) Characterisation of Urban Air Quality Indoor/Outdoor Particulate Matter Chemical Characteristics and Source-to-Inhaled Dose Relationships URBAN EXPOSURE (Dr Trond Bohler, NILU) Integrated Exposure Management Tool Characterising Air Pollution Relevant Human Exposure in Urban Environment Slide 20 Eleven Participating Projects FP5, EESD, City of Tomorrow BOND (Coordinator: Professor John Bartzis, NCSRD) Biogenic Aerosols and Air Quality in the Mediterranean Area MERLIN (Coordinator: Professor Rainer Friedrich, University of Stuttgart) Multi-pollutant, Multi-Effect Assessment of European Air Pollution Control Strategies: an Integrated Approach AIR4EU (Coordinator: Professor Peter Biltjes, TNO) FP6 Project -Air Quality Assessment for Europe: Local to Continental Scales INTEGAIRE (Coordinator: Dr Eva Banos, EUROCITIES) - Integrated Urban Governance and Air Quality Management in Europe Slide 21 CLEAR 20 Partner Countries Slide 22 FUMAPEX: Integrated Systems for Forecasting Urban Meteorology, Air Pollution and Population Exposure FUMAPEX: Integrated Systems for Forecasting Urban Meteorology, Air Pollution and Population Exposure Project objectives: (i)the improvement of meteorological forecasts for urban areas, (ii)the connection of NWP models to urban air quality (UAQ) and population exposure (PE) models, (iii)the building of improved Urban Air Quality Information and Forecasting Systems (UAQIFS), and (iv)their application in cities in various European climates. Slide 23 UAQIFS: Scheme of the suggested improvements of meteorological forecasts (NWP) in urban areas, interfaces to and integration with UAP and PE models Slide 24 FUMAPEX target cities for improved UAQIFS implementation #1 Oslo, Norway #2 Turin, Italy #3 Helsinki, Finland #4 Valencia/Castellon, Spain #5 Bologna, Italy #6 Copenhagen, Denmark Different ways of the UAQIFS implementation: (i)urban air quality forecasting mode, (ii) urban management and planning mode, (iii) public health assessment and exposure prediction mode, (iv) urban emergency preparedness system. Slide 25 FUMAPEX: Forecast procedure in Oslo Slide 26 COST 728: Enhancing meso-scale meteorological modelling capabilities for air pollution and dispersion applications (2004-2009) The Action will encourage the advance of the science in terms of parametrisation schemes, integration methodologies/strategies, air pollution and other dispersion applications as well as developing model evaluation methods. In terms of air pollution applications it is recognised that chemical mechanisms and emissions pre-processing are vital components. Four working groups (WG): WG1Meteorological parameterisation/applications WG2 Integrated systems of MetM and CTM: strategy, interfaces and module unification WG3 Mesoscale models for air pollution and dispersion applications WG4Development of evaluation tools and methodologies Slide 27 The overall aim of WG2 will be to identify the requirements for the unification of MetM and CTM/ADM modules and to propose recommendations for a European strategy for integrated mesoscale modelling capability. WG2 activities will include: Forecasting models Assessment models WG2: Integrated systems of MetM and CTM/ADM: strategy, interfaces and module unification Slide 28 Meteorology and Air Pollution: as a joint problem Meteorology is a main source of uncertainty in APMs => needs for NWP model improvements Complex & combined effects of meteo- and pollution components (e.g., Paris, Summer 2003) Effects of pollutants/aerosols on meteo&climate (precipitation, thunderstorms, etc) Three main stones for Atmospheric Environment modelling: 1.Meteorology / ABL, 2.Chemistry, => Integrated Approach 3.Aerosol/pollutant dynamics (chemical weather forecasting) 4.Effects and Feedbacks Slide 29 Why we need to build the European integration strategy? European mesoscale MetM/NWP communities: ECMWF HIRLAM COSMO ALADIN/AROME UM --------- WRF MM5 RAMS European CTM/ADMs: a big number problem oriented not harmonised (??) .. NWP models are not primarily developed for CTM/ADMs and there is no tradition for strong co-operation between the groups for meso/local-scale the conventional concepts of meso- and urban-scale AQ forecasting need revision along the lines of integration of MetM and CTM US example (The models 3, WRF-Chem) A number of European models A universal modelling system (like ECMWF in EU or WRF-Chem in US) ??? an open integrated system with fixed architecture (module interface structure) Slide 30 ACCENT's goals are to promote a common European strategy for research on atmospheric composition change, to develop and maintain durable means of communication and collaboration within the European scientific community, to facilitate this research and to optimise two-way interaction with policy-makers and the general public. Changes in atmospheric composition directly affect many aspects of life, determining climate, air quality and atmospheric inputs to ecosystems. In turn, these changes affect the fundamental necessities for human existence: human health, food production, ecosystem health and water. Atmospheric composition change research is therefore fundamental for the future orientation of Europe's Sustainable Development strategy. Slide 31 Slide 32 Part II: Structure of the urban boundary layer Vertical structure Horizontal non- homogeneity Temporal variability Slide 33 The atmospheric boundary layer Lowest layer of the atmosphere Interactions with the earths surface are important Diurnal evolution is complicated Turbulence generation by shear and buoyancy is important Fluxes of energy, momentum, and moisture to/from the surface Slide 34 Problems in defining the boundary layer Complicated vertical structure Sub-layers grow and decay over the diurnal cycle Turbulence is often intermittent, complicating the classification of stability Boundary layer top is not necessarily at inversion Slide 35 The structure of the urban boundary layer - meteorological view after T. Oke (1988) Slide 36 Slide 37 Scales in an Urban Environment Slide 38 Diurnal evolution of the PBL Slide 39 Diurnal evolution of urban BL day night Slide 40 Boundary layer characteristics Daytime: Deep mixed layer from surface heating Turbulent eddies on the scale of BL depth Thermally driven flows can develop from spatial variations in surface heating Nighttime: Surface inversion develops from radiational cooling Mixed layer can persist above inversion Turbulence can be intermittent and mix down faster and warmer air Slide 41 Part III: Ways to resolve the UBL structure 1. Obstacles-resolved numerical models - CFD => turbulent closure, bc, geometry, etc. - LES, , DNS - simple box models 2. Parameterization of sub-grid processes - theoretical - experimental - numerical 3. Downscaling of models / Nesting techniques - NWP-local-scale meteorological models - Mesoscale models CFD tools - Mesoscale models Parameterized models Slide 42 Key parameters for urban models of different scales (COST715) Slide 43 One example of the first way (CFD) Scheme of the building complex and 6 m height horizontal wind field (after Mastryukov et al.) Slide 44 High-resolution mapping of urban areas CORINE and PELCOM data up to 250 m resolution Land-use database with the resolution 25 x 25 meters (DMU) GIS databases of urban structure (BlomInfo A/S) Slide 45 Slide 46 Momentum equations for urban canopy model Slide 47 1.Modifying the existing non-urban (e.g. MOST) approaches for urban areas by finding proper values for the effective roughness lengths, displacement height, and heat fluxes (adding the anthropogenic heat flux, heat storage capacity and albedo change). In this case, the lowest model level is close to the top of the urban canopy (displacement height), and a new analytical model is suggested for the Urban Roughness Sublayer which is a critical region where pollutants are emitted and where people live. 2.Alternatively, source and sink terms are added in the momentum, energy and turbulent kinetic energy equation to take into account the buildings. Different parameterizations (Masson, 2000; Kusaka et al., 2001; Martilli et al., 2002) had been developed to estimate the radiation balance (shading and trapping effect of the buildings), the heat, the momentum and the turbulent fluxes inside the urban canopy, taking into account a simple geometry of buildings and streets (3 surface types: roof, wall and road). Two approaches to parameterise the urban canopy effect: Slide 48 Slide 49 Wind tunnel data for urban canopy Slide 50 Review: theories relating to urban wind profiles (WG1 COS715) Theories will be required for various aspects of the UWF: Roughness sublayer (RS): profile of Reynolds stress & local scaling within RS wind profile no theory, but good results; parameterisation exists for Reynolds stress profile (to be extended to more data sets) Required: friction velocity of inertial sublayer (IS), ; z * and d Stability effects? (profile of sensible heat flux? WG2) Urban canopy (part of RS) Little variation within canopy [height and position] Sharp transition from canopy to above roof region Similar to plant canopies: Theory? (Raupach et al., 1996) Possible approach: match the canopy and the RS profiles for 0