Page 1 Crown copyright 2004 Unified Model Developments 2005 for EWGLAM/SRNWP Annual Meeting October 2005, Ljubljana, Slovenia Mike Bush NWP Page 2 Crown copyright Current UM configurations and future plans 2.Global model 3.Global and regional ensembles 4.NAE (North-Atlantic European) model 5.CAMMS and Africa model 6.HRTM 7.U.K 4km model Page 3 Crown copyright 2004 Global 60Km NAE 12Km UK Mes 12Km Current NWP Model Configurations CAMMs 38 levels UK 4km Africa 20km Trial ensemble Global 90km & Regional 24km Page 4 Crown copyright 2004 Global 40Km NAE 12Km 2006: NWP Model Configurations CAMMs 70 levels UK 4km Africa 20km Trial ensemble Global 90km & Regional 24km Page 5 Crown copyright 2004 Supercomputers for NWP and Climate NEC SX6 Operational since April 2004 Twin 15 node system 1.86 TFlop April 2005 Upgrade Additional 4 SX6 nodes Plus 16 node NEC SX8 4.08 TFlop Will allow the running of ensembles and increased resolution models including those used in climate research Page 6 Crown copyright Current UM configurations and future plans 2.Global model 3.Global and regional ensembles 4.NAE (North-Atlantic European) model 5.CAMMS and Africa model 6.HRTM 7.U.K 4km model Page 7 Crown copyright 2004 Global model developments G33 5 th October 2004 Introduction of 4D-VAR. G34 18 th January 2005 HadGEM physics upgrade G35 8 th February 2005 Data Assimilation upgrade. G36 14 th June 2005 DA and satellite upgrade. G37 17 th August 2005 Implementation of a soil moisture nudging scheme. Page 8 Crown copyright 2004 Global model cycle G34 18 th Jan 2005 Introduction of HadGEM physics 3C Large Scale precipitation scheme (replacing 3B). 8B Boundary Layer (replacing 8A). Increase in Saharan surface albedos. Benefits Improved tropical performance o Increased (Reduced) Precipitation over land (Ocean). o Improved tropical circulation & winds. Reduced low cloud (Iraq); Improved 1.5m T. Improved surface T and circulation over Sahara. Drawbacks Increase existing warm bias in extratropics Page 9 Crown copyright 2004 Systematic Errors in Tropical Precipitation Page 10 Crown copyright 2004 Impact of 30min CAPE closure Page 11 Crown copyright 2004 Global model cycle G37 17 th Aug 2005 Implementation of a soil moisture nudging scheme Replaces the weekly resetting to climatology. Errors in the 6-hour forecasts of screen temperature and humidity are used to infer corrections to the soil moisture field. The scheme derives these from the physics of the land- surface model. Summer trials showed improvements to surface and boundary-layer temperature forecasts. Winter results were close to neutral. Page 12 Crown copyright 2004 Planned Global Changes (2005-6) 1.4D-Var upgrade better incremental physics, less obs thinning (ATOVS) 2.Increased Resolution (phase 1) ~ 40 km, ~50 level 3.Better use of Satellite Data SSMI-S, Microwave Cloudy radiances, MSG winds (Meteosat 7 -> 8) 4.Convection and Boundary Layer tuning 5.Increased Resolution (phase 2) -> 70 levels 2005Q3 2005Q4 2006Q1 2006Q Page 13 Crown copyright Current UM configurations and future plans 2.Global model 3.Global and regional ensembles 4.NAE (North-Atlantic European) model 5.CAMMS and Africa model 6.HRTM 7.U.K 4km model Page 14 Crown copyright 2004 Introduction of Ensembles 1.GEPS1 14 th June 2005 24 member Global Ensemble at N144 (~90km) resolution twice per day (00Z, 12Z) to T+72 hours. ETKF perturbations, stochastic physics Initially there will be a one year trial in which forecasters can view output on the internal web 2.EPS1 17 th August 2005 24 member North Atlantic/European Ensemble at 24km resolution twice per day (06Z, 18Z) to T+36 hours IC perturbations taken directly from global model Nested within global ensemble for LBCs 3.Plans to engage in multi-model ensembles with USA and Canada (THORPEX). Proof of concept by March 2006 Page 15 Crown copyright 2004 MOGREPS Spaghetti chart Page 16 Crown copyright 2004 MOGREPS Probability map Page 17 Crown copyright Current UM configurations and future plans 2.Global model 3.Global and regional ensembles 4.NAE (North-Atlantic European) model 5.CAMMS and Africa model 6.HRTM 7.U.K 4km model Page 18 Crown copyright 2004 NAE model developments E5 18 th January 2005 Change in domain E6 22 nd February 2005 Horizontal resolution increased from 20km to 12km. E7 14 th June 2005 New surface soil moisture analysis. E8 17 th August 2005 Removal of truncation of vertical modes in VAR from 21 to full 38. Page 19 Crown copyright 2004 Planned NAE Changes (2005-6) 1.Use of modified Global covariances 2.Introduction of HadGEM physics 3.Introduction of 4D-Var 4.More new satellite data Full resolution AMSU-B, Assimilation of GPS data, MODIS winds etc. 5.Increased Resolution 70 levels 2005Q3 2005Q4 2006Q1 2006Q Page 20 Crown copyright 2004 NAE model cycle E9 12 th Oct 2005 Use of modified Global covariances Generated using the NMC method Replaces the use of U.K Mes covariances. Global covariances fit less closely to obs but the horizontal length scales are longer. Large improvements to the performance of the model Ideally would use NAE covariances, but forecast differences are dominated by the use of different lateral boundary conditions. Page 21 Crown copyright 2004 NAE PMSL bias and RMSE Page 22 Crown copyright 2004 NAE 10m wind speed bias and RMS Vector Error Page 23 Crown copyright 2004 NAE Screen level temperature bias and RMSE Page 24 Crown copyright 2004 NAE performance issues The NAE model (12km resolution) covers the North Atlantic it is unusual for a LAM to cover such a large sea area. Rationale is that by modelling the North Atlantic at high resolution, forecasts for Europe will be better than if a smaller domain over Europe was chosen. Choice of covariances of crucial importance to the model performance (must do a good job over both sea and land). The Global model does a good job at synoptic scales and the NAE has struggled to do a better job than it at these scales (lateral boundary conditions dont help either). LAMs are good at adding detail to Global model output. Page 25 Crown copyright Current UM configurations and future plans 2.Global model 3.Global and regional ensembles 4.NAE (North-Atlantic European) model 5.CAMMS and Africa model 6.HRTM 7.U.K 4km model Page 26 Crown copyright 2004 Current Operational CAMM configurations Southern Asia CAMM Southern Asia (17km) Falklands (12km) Page 27 Crown copyright 2004 Bay of Bengal CAMM (Tsunami Aid effort) Bay of Bengal CAMM 17km 00z and 12z T x levels Requested Tuesday 4 th Jan Delivered to Operations Thursday 6 th Jan Operational Monday 10 th Jan Page 28 Crown copyright 2004 USA CAMM: Hurricane Rita Global Model (60km)USA CAMM (17km) 70kt 10m wind, 962mb Global model central pressure: 992mb USA CAMM central pressure: 972mb NHC advisory (estimate): 929mb Page 29 Crown copyright 2004 USA CAMM: Hurricane Rita Global Model (60km)USA CAMM (17km) 70kt 10m wind, 962mb USA CAMM has track slightly west of the Global model Page 30 Crown copyright 2004 African LAM Met Office vision: increased focus on assisting developing countries / disaster mitigation Introduced into the Operational Suite on 13 th April 2005 Currently one forecast a day (00Z) to T+48 20km horizontal resolution Contains HadGEM physics Introduction of data assimilation (6 hour cycle) in Winter 2005/2006 Increased vertical resolution (2006) Page 31 Crown copyright 2004 African LAM Page 32 Crown copyright 2004 Africa LAM rainfall on 16th April 2005 TRMM =Tropical Rainfall Measurement Mission satellite Page 33 Crown copyright Current UM configurations and future plans 2.Global model 3.Global and regional ensembles 4.NAE (North-Atlantic European) model 5.CAMMS and Africa model 6.HRTM 7.U.K 4km model Page 34 Crown copyright 2004 HRTM Model Centred Over the Chilbolton Radar (High Resolution observational data for evaluation and validation) HRTM 4 km nested in operational UK-MES. Used for research and to provide lateral boundary conditions to the HRTM 1 km Over two years in development Basis for the now operational UK4 model Continued development High Resolution Trial Model Page 35 Crown copyright 2004 HRTM Scientific Options Dynamics: Non hydrostatic, Semi-Lagrangian advection and Semi-Implicit time integration (New Dynamics). Boundary Layer: 1 st order non-local K scheme with explicit entrainment. Horizontal diffusion: Del-4 operator in U, V, Q, and Theta. Microphysics: Mixed phase scheme + 3D advection of precipitation products. Radiation: Two stream scheme with 5 spectral bands for short wave and 5 for long wave Page 36 Crown copyright 2004 HRTM Scientific Options (Convection) Deep convection: explicitly resolved Shallow convection: parametrised Solution based on the operational mass flux scheme with CAPE closure CAPE reduction timescale dependent on CAPE. Large values of CAPE: CAPE reduction timescale increases. Activity of convection scheme reduced and deep convection is explicitly resolved. Small CAPE: Minimum value of CAPE timescale fixed. Shallow convection processes are taken into account. Delay in the onset of convection as the convection scheme is made less active. Page 37 Crown copyright 2004 HRTM Scientific Options (Convection) Function chosen: linear with CAPE for large CAPE values and exponential for small CAPE values min governs activity of convection scheme for small CAPE values min / CAPE min governs the asymptotic slope of the function and is related to the limit to the cloud base mass flux Page 38 Crown copyright 2004 HRTM Tests: Effect of lateral boundary updating frequency 60 minutes 30 minutes 15 minutes Chosen frequency: 30 minutes Page 39 Crown copyright Current UM configurations and future plans 2.Global model 3.Global and regional ensembles 4.NAE (North-Atlantic European) model 5.CAMMS and Africa model 6.HRTM 7.U.K 4km model Page 40 Crown copyright 2004 UK4 Model 320 rows by 288 columns degrees gridlength (4 km aprox.) 38 Levels (13 in boundary layer) 100 seconds timestep Same scientific settings as HRTM Page 41 Crown copyright 2004 UK4 Model (Pre-operational tests) 21 Case studies: Coverage of all main weather regimes, although biased towards severe weather events. Nested in UK-MES (12 km) Continuous trial 1 st of March to 1 st of April 2005, at 00 and 12 UTC Varied weather through the period Nested in operational NAE (12 km) Testing strategy Page 42 Crown copyright 2004 Case study 11/08/04 18Z Organised convection Banded structure in the 6hr ppn accumulation compares well with radar. Page 43 Crown copyright 2004 Case study 11/08/04 18Z Organised convection However the banded structure persists in the 24hr accumulation while the radar image is smooth. Better agreement when averaged to a 12km grid. Page 44 Crown copyright 2004 UK4 Model (Pre-operational tests) Borders Grid Point Storm (03/08/ Z, T+13) Page 45 Crown copyright 2004 UK4 Model (Pre-operational tests) Page 46 Crown copyright 2004 UK4 Model Pre-operational tests summary Very robust Small structure of precipitation too persistent Unrealistically high single row/point precipitation rates (grid point storms) Better forecast of fog than coarser resolution operational models Negative cloud bias (operational models use a cloud enhancement scheme) Diurnal cycle in screen temperature bias due to cloud bias PMSL errors strongly linked to errors in the driving model Page 47 Crown copyright 2004 Introduction into operations of the UK4 Model U th April 2005 One forecast per day to T+36 at 00Z U th June 2005 Extra T+36 forecast at 12Z added No operational failures. Negative cloud bias confirmed. Feedback from forecasters: Positive overall. Number of false alarms of heavy precipitation events. Excessive precipitation rates and organisation of ppn. Too much light precipitation was observed, as statistics for longer periods were available. Page 48 Crown copyright 2004 UK4 Operational (North Yorkshire floods) Rye Valley floods. 19/06/2005 Good guidance at T+17 in intensities, time and locationBut false alarm over South Wales at T+9 12-18Z Radar 12Z 6 hr rainfall MES 12Z 6 hr rainfall4 km 12Z avg 6 hr rainfall Error scale (km) Rainfall threshold (mm) 19 June 2005 Flash flooding caused by thunderstorms over North Yorkshire Page 50 Crown copyright 2004 UK4 model cycle U4.03 12 th Oct 2005 Upgrade of convection scheme to current operational version. Keeping the CAPE dependent CAPE closure modification. Substitute horizontal diffusion of moisture by targeted diffusion of moisture. Include cloud enhancement scheme. Tune microphysics parameters to reduce excessive light precipitation Page 51 Crown copyright 2004 UK4 Operational (Next upgrade) Page 52 Crown copyright 2004 Planned UK4 changes December 2005: Introduce 3D VAR assimilation system (plus Analysis Correction scheme for cloud and precipitation). Introduce orographic wave drag parametrisation. Introduce anthropogenic urban heat source. Introduce daily initialisation of soil moisture 2006: Increase vertical resolution. Introduce seasonal variability in Leaf Area Index Split urban tile type in rooftops and street canyons Review convection scheme Page 53 Crown copyright 2004 Questions?