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Urban Modelling 1 03/2003 © Crown copyright Urban Scale NWP with the Met Office's Unified Model Peter Clark Mesoscale Modelling Group Met Office Joint Centre for Mesoscale Meteorology University of Reading
Urban Modelling 2 03/2003 © Crown copyright Why Mesoscale Models? Mesoscale variation of boundary layer structure due to: –Changes in surface characteristics. »Urban/rural »Land/sea »Soil moisture/surface temperature –Orography. Mesoscale flows induced by above. –Land/sea breeze. –Drainage flows. Mesoscale structure in synoptic meteorology –Fronts –Convective storms Air Quality Weather Forecasting
Urban Modelling 3 03/2003 © Crown copyright Why the Unified Model (UM)? Non-hydrostatic, fully compressible, deep atmosphere. Suitable for use at very high spatial resolution. The UM surface exchange scheme treats urban areas and is being improved. Data assimilation is a powerful tool; makes UM data a major resource. UM availability and improvements. –Available to and adopted by NERC community. –Portable UM 5 released VERY soon. –SLICE: A Semi-Lagrangian Inherently Conserving and Efficient scheme for transport problems Operational Plans: –UK ~4 km –1 km ~ for v short range.
Urban Modelling 4 03/2003 © Crown copyright Example results from High Resolution Trial Model Visibility (m) 12 km 4 km1 km
Urban Modelling 5 03/2003 © Crown copyright Blending Height Surface UM Tile surface exchange Treats heterogeneous surfaces using blending height techniques. Nine surface types, –Broad Leaf Trees –Needle Leaf Trees –C3 Grass –C4 Grass –Shrub –Urban –Water –Soil –Ice Each tile has fixed characteristics. 4 layer soil temperature and moisture.
Urban Modelling 6 03/2003 © Crown copyright s T s 4 g T g 4 H E s T s 4 G RNRN Urban Tiles Each tile has a full surface energy balance. This includes a radiatively coupled canopy. In the urban case this has high thermal inertia to simulate wall effects. Work in progress (Reading) to improve representaion, especially of radiative effects.
Urban Modelling 7 03/2003 © Crown copyright 12 km 4 km 1 km Model Configuration Met Office non-hydrostatic semi- implicit, semi-Lagrangian Unified Model, 38 levels on stretched height based terrain following grid. One-way nested –Global (~60km) 20 min timestep –~12 km (146X182) 5 min timestep –~4 km (300x300) 2 min timestep –~1 km (300x300) 0.5 min timestep 12 km down to 1 km run from operational 3D VAR mesoscale analysis at 12Z 10th May 2001 Tiled land surface scheme using CEH 25 m Landsat based land-use including urban fraction. Model ignores man-made heat sources
Urban Modelling 8 03/2003 © Crown copyright Example 1 km domain Orography Urban Fraction in Land Use Grass Fraction in Land Use
Urban Modelling 9 03/2003 © Crown copyright Formation of the night time urban heat island Light Wind 00Z 11/05/2001 Urban-No-Urban Near surface temperature difference
Urban Modelling 10 03/2003 © Crown copyright Urban fraction Point 1: 1 % Point 2: 97 % Point 3: 50 % Point 4: 1 % Urban Fraction and contours of Urban Impact on 20 m Temperature Z 11/05/2001
Urban Modelling 11 03/2003 © Crown copyright Point 2 Point 3 Point 1 Point 4 Point 1: Upstream Point 2: Central London Point 3: Downstream Suburbs Point 4: Downstream Rural Evolution of vertical structure over London
Urban Modelling 12 03/2003 © Crown copyright Impact on vertical mixing. Urban Area produces 200 m near neutral boundary layer Central London
Urban Modelling 13 03/2003 © Crown copyright Tracer release broadly reflecting smoothed emissions Afternoon deep convection brings down clean air Night time stabilization Blocking of flow by North Downs Arbitrary Units Predictable? Unpredictable!
Urban Modelling 14 03/2003 © Crown copyright Regional tropospheric data assimilation of tracers/chemistry? Ambitious, but shouldnt we be? 3D VAR stratospheric chemistry, tropospheric 'aerosol' already a reality. DA discipline forces objective analysis of model error, observation error and representativity/covariance. 4D VAR of tracers has potential to improve model transport as well as provide concentration fields. Tracer assimilation straightforward using model dynamics. Conceivable using alternative dispersion if incorporated into UM. DARC
Urban Modelling 15 03/2003 © Crown copyright Towards a Modelling Strategy Based on the Unified Model Provision of higher resolution UM output to drive offline transport/dispersion (NAME + Others). Use of UM in NERC community to validate/improve meteorology. –Benefits of using operational analyses including sub-surface. Closer coupling of transport/chemistry with UM. –Using UM transport OR alternative (NAME, parcel, Eulerian) –Consistent physics –Shorter updating interval for winds Start thinking in a data assimilation framework –Model error covariances –Observation representativity defined with respect to model. Eventual implementation of multiscale DA of quasi-conserved species.
© Crown copyright Met Office Regional climate model formulation PRECIS Workshop, Reading University, 23 rd – 27 th April 2012.
The University of Reading Helen Dacre AMS 2010 Air Quality Forecasting using a Numerical Weather Prediction Model ETEX Surface Measurement Sites.
The University of Reading Helen Dacre UM user 2009 Forecasting the transport of pollution using a NWP model ETEX Surface Measurement Sites.
Regional Models Lake Victoria Model Prepared by C. Tubbs, P. Davies, Met Office UK Revised, delivered by P. Chen, WMO Secretariat SWFDP-Eastern Africa.
Page 1© Crown copyright 2005 Use of EPS at the Met Office Ken Mylne and Tim Legg.
The University of Reading Helen Dacre AGU Dec 2008 Boundary Layer Ventilation by Convection and Coastal Processes Helen Dacre, Sue Gray, Stephen Belcher.
Regional Modelling Prepared by C. Tubbs, P. Davies, Met Office UK Revised, delivered by P. Chen, WMO Secretariat SWFDP-Eastern Africa Training Workshop.
13 th SRNWP / 28 th EWGLAM Meeting Zürich, 9 – 12 Oct current status long-term strategy mid-term strategy some ongoing.
Page 1© Crown copyright Some Strengths and Weaknesses of ECMWF Forecasts for the UK Tim Hewson 15 th June 2006 Contributors include: Eleanor Crompton,
Peter Cox (Met Office) Martin Heimann, Wolfgang Knorr (MPI-BGC) Tony Hollingsworth, Richard Engelen (ECMWF) Philippe Ciais, Philippe Peylin (LSCE) Alain.
Integrated Systems for Forecasting Urban Meteorology, Air Pollution and Population Exposure (FUMAPEX ) Integrated Systems for Forecasting Urban Meteorology,
ECMWF DA/SAT Training Course, May The Operational Data Assimilation System Lars Isaksen, Data Assimilation, ECMWF Overview of the operational data.
Training Data assimilation and Satellite Data – Johannes Flemming Modelling and Assimilation of Atmospheric Chemistry
© Crown copyright Met Office Development of NWP-based Nowcasting at the Met Office -The Nowcasting Demonstration Project Workshop on Use of NWP for Nowcasting.
Training Course 2009 – NWP-DA: Operational and Research Activities at ECMWF 1/44 Operational and Research Activities at ECMWF Renate Hagedorn European.
ECMWF Governing Equations 1 Slide 1 Governing Equations I: reference equations at the scale of the continuum by Sylvie Malardel (room 10a; ext. 2414) after.
Training Course 2009 – NWP-NM: Operational and Research Activities at ECMWF 1/46 Operational and Research Activities at ECMWF Renate Hagedorn European.
Training Course 2009 – NWP-PR: Operational and Research Activities at ECMWF 1/45 Operational and Research Activities at ECMWF Renate Hagedorn European.
Global Earth-system Monitoring using Space & in-situ data, A.Hollingsworth ECMWF Seminar Sept 2003 Slide 1 GEMS Global Earth-system Monitoring using Space.
An Overview of Numerical Weather Prediction Models.
Page 1© Crown copyright Operational Use of ECMWF products at the Met Office: Current practice, Verification and Ideas for the future Tim Hewson 17 th June.
Problems With Model Physics in Mesoscale Models Clifford F. Mass, University of Washington, Seattle, WA.
1 PV Generation in the Boundary Layer Robert Plant 18th February 2003 (With thanks to S. Belcher)
DYMECS: Dynamical and Microphysical Evolution of Convective Storms (NERC Standard Grant) University of Reading: Robin Hogan, Bob Plant, Thorwald Stein,
Laura Davies, University of Reading, UK. Supervisors: Bob Plant, Steve Derbyshire (Met Office)
The equations of motion and their numerical solutions I by Nils Wedi (2006) contributions by Mike Cullen and Piotr Smolarkiewicz.
Philip N. Schumacher 11 December 2007 This talk is based on work done with Dr. Martin Baxter of Central Michigan University and Josh Boustead of WFO OAX.
Gettelman: November 2006 An Introduction to Climate Modeling Andrew Gettelman National Center for Atmospheric Research Boulder, Colorado USA Assistance.
Plans for "Sochi-2014 Olympic and Paralimpic Games (February 8-23 and March 7-16, 2014) Dmitry Kiktev, Hydrometcentre of.
1 00/XXXX © Crown copyright Carol Roadnight, Peter Clark Met Office, JCMM Halliwell Representing convection in convective scale NWP models : An idealised.
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