The DAPPLE project: Overview and wind tunnel experiments Alan Robins 1, Paul Hayden 1, Janet Barlow 2, and the DAPPLE Consortium Home Office CBRN S&T Programme 2 University of Reading, UK 1 University of Surrey, UK

Cities are collections of relatively short streets between intersections - the classical street canyon is a rarity.

Dispersion through an intersection Scaperdas, A (2000), PhD thesis, Imperial College London What is the impact of the street network on dispersion of and exposure to pollutants?

Dispersion of Air Pollutants and their Penetration into the Local Environment Surrey - project leader, wind tunnel modelling Bristol - tracer studies, analysis Cambridge - tracer studies, modelling & applications Imperial - field site management, exposure, modelling & applications Leeds - traffic movement, emissions, pollution & wind field measurement Reading - meteorology, wind field & modelling Golder Associates (UK) Ltd. (from 2006) - field site management

Support and practical outputs Additional support from GLA, APRIL, DEFRA, EA, DSTL (Porton Down), HSE, BRE, NRPB, NSCA, other UK CCs, Din Café & Restaurant. In collaboration with TfL, Westminster CC, Camden CC, UK Met Office, HSL, NERI, other UK universities and projects With approval from Met. Police, TfL, Westminster CC, HSE, UK Government Strategies to control personal exposure Guidance on the effectiveness of air quality management strategies; traffic queue and flow control Education and training material for local authorities and emergency responders

Chronology 2002 EPSRC-DAPPLE start 2003 Spring field work 2004 Spring and Autumn field work 2005 Analysis, workshops, dissemination 2006 EPSRC-DAPPLE end DAPPLE-HO start 2007 Spring/Summer field work Winter/Spring 07/08 field work Data release by Home Office end 2009 Arnold S et al. (2003) STOTEN Wood C R et al., in press BAMS

Routes used in personal exposure study

CO T15 Langan measures carbon monoxide every 10 seconds TSI P-Trak measures ultra-fine particles every second Casella Ultraflow Pump + Filter measures average PM 2.5 concentration for the route Personal Exposure Voice and video Kaur S et al. (2005, 2006) Atmospheric Environment

Field Instrumentation 7 to 11 sonic anemometers References on rooftops and at 190m on BT Tower Automatic Weather Stations, Doppler lidar and Met Office forecasts CO/NO 2 Learian Street Boxes; Instrumented Vehicle; SCOOT (traffic data) 3 PFC tracer release kits, 18 tracer sampling units people on-site (exposure measurement, tracer studies)

Wind tunnel flow visualisation

Wind tunnel research mixed basic and detailed 1:200 scale model EnFlo 20x3.5x1.5 m boundary layer wind tunnel U = 0 to 3.5 m s -1 ; inlet flow heating; surface heating and cooling

Large Eddy Simulation Flow structure at an intersection Smoke source in Gloucester Place, south of Marylebone Road; wind from the SW. Carpentieri M et al., submitted Atmospheric Environment

Tracer release examples Field tracer studies yield sets of examples drawn from ensembles in which the mean and standard deviation are of the same magnitude. Receptor at plume centre Receptor at plume edge White - ensemble average (~ 100 realisations) Red - single example Simulation of 15 minute release at full scale

Dispersion and intersections The basic mean concentration decay function, CUH 2 /Q = 12 (R/H) -2

Summary DAPPLE project – extensive UK dispersion study in urban area Short range dispersion (0 – 1km) 51 full-scale tracer experiments; point and mobile source releases Detailed wind tunnel and full-scale flow measurements Intensive fixed and mobile pollution measurements Fully integrated traffic, pollution, flow and exposure measurements For further information and data queries contact: Project leader Alan Robins