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Le projet CRTI: d é veloppement d’un syst è me de mod é lisation à l’ é chelle urbaine

Le projet CRTI: d é veloppement d’un syst è me de mod é lisation à l’ é chelle urbaine. Jocelyn Mailhot Stéphane Bélair Mario Benjamin Najat Benbouta Bernard Bilodeau Gilbert Brunet Frédéric Chagnon Michel Desgagné Jean-Philippe Gauthier Bruno Harvey Richard Hogue. Michel Jean

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Le projet CRTI: d é veloppement d’un syst è me de mod é lisation à l’ é chelle urbaine

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  1. Le projet CRTI: développement d’un système de modélisation à l’échelle urbaine Jocelyn Mailhot Stéphane Bélair Mario Benjamin Najat Benbouta Bernard Bilodeau Gilbert Brunet Frédéric Chagnon Michel Desgagné Jean-Philippe Gauthier Bruno Harvey Richard Hogue Michel Jean Aude Lemonsu Alexandre Leroux Gilles Morneau Radenko Pavlovic Pierre Pellerin Claude Pelletier Lubos Spacek Linying Tong Serge Trudel Yufei Zhu RPN / CMC / Région du Québec Séminaire CMC / RPN – 24 février 2006

  2. Objectives and Context • Improve the representation of cities in Canadian meteorological models: • accurate prediction of urban flows and atmospheric dispersion over major North American cities. • improve urban surfaces and urban boundary layer in meso--scale and micro--scale (~ 20km down to 200m) atmospheric models • Part of a larger-scale project within CRTI: • development of an integrated multi-scale modeling system • to provide decision making framework to minimize consequences • injuries, casualties, and contamination • prototype for Environmental Emergency Response Division in 2007 • Project partners: • R&D Defence Canada, AECL • Universities of Waterloo and Calgary • CFD microscale models (at street- and building-scales) • Lagrangian stochastic dispersion models

  3. Urban Modeling System Off-line surface modeling At 100-200 m « Urbanized » Regional-15 km GEM-variable Built areas are parameterized, i.e., we need • TEB • Urban surfaces IC + LBC 1D (vertical) turbulence is sufficient • TEB • Urban surface databases • Anthropogenic heat sources « Urbanized » Meso--scale 2.5 km GEM-LAM Operational IC + LBC Prototype « Urbanized » Micro--scale 250 m MC2-LAM 3D turbulence is required interface still TBD IC + LBC High-res Microscale (CFD) Partners Built areas are resolved

  4. WORK BREAKDOWN STRUCTURE High-level management (Jean, Hogue) Scientific management (Mailhot, Bélair) MEASUREMENTS and OBSERVATIONS MODELING DATABASES TRANSFERS Meso- and off-line TEB Surface fields MUSE-1 Anthropo. heat sources 3D-turbulence MUSE-2 Regional NWP CFD

  5. List of Activities

  6. Urban Modeling System • Main features of the new urban modeling system: • High-resolution capability for micro-α scale applications (down to ~250m) • Urban processes with Town Energy Balance (TEB) scheme (Masson, 2000) • Generation of fields characterizing urban type covers (Lemonsu et al., 2006) • 3D LES-type turbulent diffusion scheme. • First validation of the urban modeling system: • Impact of urban processes on structure of urban boundary layer • Comparison against observations from the Joint Urban 2003 experimental campaign in Oklahoma City in July 2003 (Allwine et al., 2004) • Comparison against observations from MUSE-1 (March-April 2005) for cold conditions and snow melt period.

  7. roof wall wall road TEB urban surface scheme Town Energy Balance (Masson, 2000) • Urban canopy model parameterizing water and energy exchanges between canopy and atmosphere (based on urban canyon concept of Oke 1987) • Model specifically dedicated to the built-up covers • Three-dimensional geometry • Radiative trapping and shadow effect • Heat storage • Wind, temperature and humidity inside the street • Water and snow • Idealized urban geometry • Mean urban canyon: 1 roof, 2 identical walls, 1 road • Isotropy of the street orientations • No crossing streets W abld zbld

  8. Water Sea ice Urban Soil/Vegetation Glaciers Coupling with MC2 and GEM To couple TEB with MC2 and GEM requires : • Implementing a new type of surface in the physics package in order to take into account the urban areas • Developing urban land-cover databases to document the spatial distribution and spatial variability of urban areas • Defining the heat and humidity releases due to human activities (Anthropogenic sources)

  9. Urban Land-Cover Classification Methodology: • Based on joint analysis of satellite imagery (ASTER, Landsat-7) and digital elevation models (SRTM-DEM, NED, CDED1) • Produce 60-m resolution urban land-use land-covers • Methodology applied to major North American cities Classification: • Horizontal resolution adapted to micro-α-scale modeling • Number of urban classes (12) allowing the representation of urban variability Interest of the method: • Semi-automatic treatment • Limited number of data sources • Large availability of the databases

  10. Methodology Surface element identification ASTER satellite image 15 m database Building height estimation SRTM-DEM - NED 1/3 10 m database • Water • Trees • Low vegetation • Grass • Bare soil and rocks • Roofs • Roads and parkings • Asphalt roads • Residential mixing • Veg/road mixing • Building height • Built fraction with elevation Classification criteria to describe the urban landscapes and identify urban classes Aggregation at a lower resolution to compute the statistics of selected criteria on the new grid Decision tree Regrouping pixels whose criteria are similar and identification of urban classes Attribution of descriptive parameters Town Energy Balance input data

  11. High buildings Mid-high buildings Low buildings Very low buildings Sparse buildings Industrial areas N Roads and parkings Road mix Dense residential Mid-density residential Low-density residential Mix of nature and built Soils Crops Short grass Mixed forest Mixed shurbs Water Excluded Urban classification OKC 60-m resolution classification Including 12 new urban classes

  12. N N High buildings Mid-high buildings Low buildings Very low buildings Sparse buildings Industrial areas Roads and parkings Road mix Dense residential Mid-density residential Low-density residential Mix of nature and built Zoom Montreal 60-m resolution classification Vancouver 60-m resolution classification

  13. Inclusion of Anthropogenic Heating Anthropogenic sources: • importance of heat and humidity releases, especially during wintertime • based on estimates for a typical US city: • ~60% due to traffic • ~40% due to residential/industrial activities • a few % due to metabolism (neglected)

  14. Anthropogenic Heating: Production of a database for Canada & USA Current TEB: • uses constant forcing of fluxes due to traffic and industrial activities Methodology: • under development for more realistic representation of anthropogenic fluxes • based on “top-down” approach of Sailor and Lu (2004) • estimates of diurnal, weekly and seasonal cycles • prototype and validation for Montreal • generalize to major North American cities

  15. Evaluation Of Anthropogenic Heating Top-down approach (D. J. Sailor, USA, 2004) Daily total energy released by 1 vehicle • ρpop(t) Population density [person/km2] • FV(t) Non-dimensional vehicle traffic profile • EVVehicle energy used per kilometer [Wkm-1] • DVD Distance traveled per person [km] • Analysis at the city scale • Hourly non-dimensional profile functions per capita • Spatial refinement through the hourly density of population profile

  16. Anthropogenic Heating: Top-Down Approach, Vehicle Traffic Profile Hourly fractional traffic profiles – fv(t) for various US cities and states (Sailor and Lu, 2004).

  17. Anthropogenic Heating: Top down approach Production of a database for Canada & USA • Plan: • Search for data sources • Analysis of the data • Definition of the anthropogenic profiles per sector • Building of the anthropogenic heating database • Validation of the approach with detailed high resolution data

  18. Implementing 3D Turbulence • Current 1D (vertical) turbulent diffusion scheme parametrizes effects of large eddies in PBL • High-resolution models (< 1km) partly resolve large eddies • Adjustments needed to avoid “double-counting” of diffusion processes • Must also include XY contributions as grid resolution increases and move toward LES (quasi-isotropic 3D diffusion) • Cascade to LES-type model resolution (Large-eddy simulation - i.e. 10-50m) with Smagorinsky-Lilly approach • Smooth transition of diffusion intensity as function of model resolution

  19. Implementing 3D Turbulence • Included all XY components of the dynamic Reynolds stress tensor • Added TKE gradient terms • Horizontal corrections introduced in all remaining transport equations • Finite difference discretization on Arakawa-C grid and Charney-Phillips vertical staggering • Modified operator splitting technique used by TKE solver • Modified appropriate scale-dependent mixing length

  20. Vertical heat flux: published LES results • 30 m resolution • SB1 and SB2: strong shear + moderate convection • SGS (sub-grid-scale parameterization) model mostly active: • - lower levels (near surface) • -top of PBL (entrainment zone) Moeng et al., J. Atmos.,Sci., 1994

  21. Vertical heat flux: resolved and subgrid scales (OKC 16:00 CDT) 40 m 200 m

  22. TKE resolved and subgrid scales (OKC 16:00 CDT) 40 m 200 m

  23. 1D vs. 3D TKE profiles (OKC 16:00 CDT) - “double-counting” problem - 40 m 200 m

  24. Modeling objectives Current studies : • Offline modeling over OKC (Joint Urban 2003) to evaluate TEB over North American cities • 3D modeling over OKC (Joint Urban 2003) to study the impact of the urban parameterization on the boundary layer Future works : • Offline modeling over Montreal (MUSE period) to evaluate TEB under winter condition and to improve the snow parameterization

  25. In collaboration with our CRTI partners (U. of Waterloo, Defence R&D Canada) The Joint Urban 2003 Experiment Atmospheric dispersion study 28 June to 31 July 2003 • Include the following meteorological measurements: • 22 surface met stations • 6 surface energy budget stations • 2 CTI windtracer lidars • 2 radiosonde systems • 4 wind profiler/RASS systems • 1 FM-CW radar • 3 ceilometers • 9 sodars • + Oklahoma mesonet • + NEXRAD radars of the US weather service

  26. Modeling configuration • Preliminary results based on Joint Urban 2003 • IOP 3 (16 July 2003) - Clear sky / southerly winds • Cascade of grid nesting down to 1-km resolution GEM/LAM 250 m GEM/LAM 1 km GEM/LAM 2.5 km

  27. Observations Simul CROPS Simul URBAN Observations Simul CROPS Simul URBAN Evaluation on Joint Urban 2003 • Sensitivity tests conducted with 2 model simulations at 1-km: • CROPS = no TEB (city is replaced by crops resolved by ISBA) • URBAN = with TEB + urban land-cover classification (12 urban classes) • Rural sites (7 MESONET stations around OKC): • good agreement on day 1 between observations and model runs • model slightly too warm during nighttime and day 2 • minor impact of TEB in rural areas (as expected) • Suburbs (PNNL stations) and urban sites (13 PWIDS stations in CBD): • marked positive impact of TEB during nighttime • significant overestimate during daytime with TEB (examination is underway)

  28. 1500 LST 1200 LST Evaluation on Joint Urban 2003 • At 1200 LST well-mixed BL (with θ ~ 34°C) to about 1300 m at upwind site (PNNL south of OKC), with strong inversion. A few km downwind (ANL site), UBL is colder (by about 1°C) and reaches height of 1200 m. • The 1-km model run indicates a relatively good agreement, except at upper levels: too much mixing in the entrainment zone! • BL warms up in afternoon (~ 36°C). While the upwind BL stays relatively steady, the UBL top rises to 1650 m at the ANL site, likely as a result of the urban heat island plume. • The 1-km model run does not capture well this evolution of the BL structure. • Work underway to improve simulations with: • Higher horizontal (250 m) and vertical resolutions (especially in entrainment zone); • More appropriate vertical diffusion scheme (3D LES-type) Evolution of the Urban Boundary Layer

  29. Preliminary results of the 2005Montreal Urban Snow Experiment (MUSE-2005) Objectives of MUSE-1 • Document the evolution of surface characteristics and energy budgets in a dense urban area during the winter-spring transition • Evolution of snow cover from ~100% to 0% in an urban environment • Impact of snow on the surface energy and water budgets • Quantify anthropogenic fluxes in late winter and spring conditions • Evaluate TEB in reproducing the surface characteristics and budgets in these conditions (aspect not well examined so far) • Gain expertise in urban measurements • Prepare for a wider effort to be submitted to CFCAS

  30. Continuous measurements17 March to 14 April 2005 20 m tower Radiative surface temperatures IR camera in heated case Incoming and outgoing radiation CNR1 radiometer Kipp & Zonen Turbulent fluxes by eddy covariance 10Hz 3D sonic anemometer CSAT3 H2O/CO2 analyzer Li-Cor 7500 Fine wire thermocouple ASPTC Air temperature and humidity in canyons Radiative temperature of walls

  31. Intensive observation periods Evolution of snow cover • Clear skies and southwest winds • Four 26-hour IOPs (March 17-18, 22-23, 30-31, April 5-6) • Measurements: • Hourly radiative surface temperatures using IR thermometer • Albedo (5 daytime measurements) • Snow depth and density (5 daytime measurements) • Pictures to document snow cover, snow melt, wet fraction March 22nd March 17th March 30th April 5th 100 % 50 % 10 % 95 %

  32. Energy balance summary Daily average in W/m² 1st sequence With snow 2nd sequence Without snow Residual term = Radiative balance – (sensible heat + latent heat)

  33. The MUSE-2005 team Project management: Michel Jean, Operations Branch, CMC, Dorval Jocelyn Mailhot, MRB, Dorval Mario Benjamin, Quebec Region - MSC Field work (installation and observations): Bruno Harvey, Frédéric Chagnon, Stavros Antonopoulos, Najat Benbouta, Mario Benjamin, Olivier Gagnon, Aude Lemonsu, Gilles Morneau, Radenko Pavlovic Modelling team: Stéphane Bélair, Aude Lemonsu, Claude Pelletier External contributions from: Prof Sue Grimmond, Indiana University Prof Tim R. Oke, University of British Columbia Prof James A. Voogt, University of Western Ontario Sarah M. Roberts This project was funded by CBRN Research and Technology Initiative as project # 02-0093RD

  34. Outlook • MUSE-2: follow-up • 10 February until end March 2006 • Wintertime conditions • Similar location (Rosemont/Petite-Patrie) and instrumentation • Longer-term wider effort in Canada: • Development of a national observation network • Urban sites for surface and upper-air profiles • Monitoring of the urban boundary layer • Partnership with various organizations across Canada • Seek funding by CFCAS (Canadian Foundation for Climate and Atmospheric Sciences)

  35. CFCAS Urban Proposal Network Grant Proposal to the Canadian Foundation for Climate and Atmospheric Sciences “FORECASTING WEATHER FOR CANADIAN CITIES” Co-Principal Investigators: J.A. Voogt (The University of Western Ontario) T.R. Oke (The University of British Columbia) Total requested Budget: $1,447,000 February 10th, 2006

  36. CFCAS Urban Proposal Table 1. Proposal participants. * Obs:field observation acquisition and analysis, Mod: numerical modeling, RS: remote sensing, TEB: TEB-ISBA use.

  37. Forecasting Weather for Canadian Cities5 Major Objectives Forecasting Weather for Canadian Cities 5 Major Objectives • Field observations (Montreal + Vancouver: urban / suburban / rural sites) • Oke, Benjamin, Strachan, Grimmond, Voogt • Detailed urban heat and water balances (continuous 2-year measurements) • Canadian optimized version of TEB-ISBA • Bélair, Lemonsu, Mailhot, Oke • Specifics of Canadian cities: building materials, vegetation, snow and cold winter conditions • Modeling studies of the urban boundary layer • Mailhot, Bélair, Lemonsu, Masson, Zawadzki • Impact of TEB on UBL and clouds/precipitation/types; urban-induced circulations • Urban component of off-line modeling system • Bélair, Lemonsu • Urban remote sensing • Voogt, Coops, Wang, Bélair, Lemonsu

  38. Presentations at conferences • Recently: • 39th Annual CMOS Congress: June 2005 in Vancouver (5 presentations) • Royal Met Society 2005 Conference: September 2006 in Exeter UK (1 presentation) • 6th Symposium on Urban Environment / AMS Annual Meeting: Jan. 2006 in Atlanta, GA (5 presentations) • Upcoming: • 17th Symposium on Boundary Layers and Turbulence: May 2006 in San Diego, CA (1 presentation) • 6th International Conference on Urban Climate: June 2006 in Göteborg, Sweden (4 presentations)

  39. Funding through… CRTI Project # 02-0093RD Advanced Emergency Response Systemfor CBRN Hazard Prediction and Assessment for the Urban Environment

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