Presentation is loading. Please wait.

Presentation is loading. Please wait.

Page 1© Crown copyright 2004 Unified Model Developments 2004 Mike Bush NWP Met Office.

Similar presentations


Presentation on theme: "Page 1© Crown copyright 2004 Unified Model Developments 2004 Mike Bush NWP Met Office."— Presentation transcript:

1 Page 1© Crown copyright 2004 Unified Model Developments 2004 Mike Bush NWP Met Office

2 Page 2© Crown copyright 2004 Outline  Operational Unified Model (UM) configurations  Recent Global Model changes and future plans  Recent Limited Area Model changes and future plans  Problems over Greenland and the Alps  UM forecasts over the U.S.A., Spain…  Future supercomputer plans  Summary

3 Page 3© Crown copyright 2004 New Headquarters & Operations Centre

4 Page 4© Crown copyright 2004 Operational UM configurations  Global  38 levels, N216= 432x325 (~60km)  North Atlantic European (NAE)  38 levels, 0.18 deg (20km)  UK Mesoscale  38 levels, 0.11 deg (12km)  Stratospheric  50 levels 100-1hpa), N48=96x73 (~300km)  Crisis models (CAMMS)  Middle East, SW Asia

5 Page 5© Crown copyright 2004 External Users  CGAM, U.K  ICM Warsaw (University), Poland  NIWA, New Zealand  met.no, Norway  INM, Spain

6 Page 6© Crown copyright 2004 Recent changes to the Global model  G32 27 th April 2004 – Upgrade to UM6.0  G33 26 th May 2004 – Additional/better use of satellite data  High spectral resolution IR sounder data (AIRS) on Aqua  30 minute locally received ATOVS data (EARS)  ATOVS over land where elevation > 1000m  AMSU-A from Aqua (redundancy with NOAA-16)  Improved RTM (RTTOV-7) in 3D-VAR  Improved bias correction (model predictor)  G34 5 th October 2004 – Introduction of 4D-VAR

7 Page 7© Crown copyright 2004 Southern Hemisphere – 500 hPa Height Stephen English > 5% better Operations 3/44 Experiment 24/44

8 Page 8© Crown copyright 2004 Forecast tracksof Super Typhoon Nida Julian Heming

9 Page 9© Crown copyright D-VAR  Has been in the pipeline for the last 10 years  Successor to 3D-VAR  Requires 3-5 times the computing resources of 3D-VAR  Single outer loop  Effective resolution is N108 (half model resolution)  Further scope for improvement via the use of more data (less temporal thinning) in 2005

10 Page 10© Crown copyright D-VAR vs 3D-VAR: % Reduction in RMSE Rick Rawlins  Positive impact in NH, SH and Tropics  Strongest signal in SH  Satellites are the main data source in the SH  Satellite data is asynoptic and so particularly suited to 4D-VAR

11 Page 11© Crown copyright D-VAR Parallel Trial and Danielle Julian Heming T+144 PMSL VT: 00Z 23/08/2004 Blue= Trial Black= Op

12 Page 12© Crown copyright D-VAR Parallel Trial Julian Heming PMSL Analysis VT: 12Z 23/08/2004

13 Page 13© Crown copyright 2004 Global future plans 2004 – 2005 Sean Milton  Saharan Albedo - November 2004  Improved Microphysics - November 2004  Boundary Layer - revised diagnosis of K profile depths - Spring 2005?  70 levels - Summer 2005 (retirement of the Stratospheric model)  Prognostic Cloud and condensate - Summer 2005  40km horizontal resolution - Summer 2005  Soil level increments from screen level data

14 Page 14© Crown copyright 2004 Global future plans 2005 – 2006 Sean Milton  Ensembles - Summer 2005  Improvements to existing convection scheme? - Autumn 2005  Entrainment (tuning)  Smooth detrainment  Mid level convection  Downdraughts  New turbulence based convection – 2006  New spectral files for radiation  Reduced thinning of satellite data

15 Page 15© Crown copyright 2004 Saharan albedo: New soil ancillary - Control Malcolm Brooks Increase in surface albedo Decrease in Max Tstar Comparisons of clear- sky albedo and OLR (GERB observations) with UM simulations reveal discrepancies over the Saharan and Saudi deserts. Clear-sky albedo was underestimated by approximately 0.05 in July 2003, causing an overestimate of the OLR by Wm2 => overestimated surface temperatures Geostationary Earth Radiation Budget

16 Page 16© Crown copyright 2004 Improved microphysics – 1.5m Temperature Malcolm Brooks Blue = Trial Red = Control RMSE Northern Hemisphere Mean of 5 cases 12Z 20/06/ Z 06/09/2004 Bias Error against Forecast range

17 Page 17© Crown copyright 2004 Recent changes to Limited area models  U.K Mesoscale  M27 17 th February Upgrade to UM5.5  Revised convection scheme   2 Targeted moisture diffusion w>1.0 ms -1  Bug fix to PMSL diagnostic  M28 27 th April 2004 – Upgrade to UM6.0  North Atlantic European (NAE)  E3 3 rd December Upgrade to UM5.5  Revised convection scheme   2 Targeted moisture diffusion w>1.0 ms -1  E4 27 th April Upgrade to UM6.0  E5 22 nd September DA/UM upgrade

18 Page 18© Crown copyright 2004 Changes to Limited area models  Balkans model  23 rd March Withdrawn (replaced by NAE)  Middle East model  27 th April Upgrade to UM6.0  South West Asia model  27 th April Upgrade to UM6.0  Falklands model (new)  5 th October Introduction

19 Page 19© Crown copyright 2004 U.K Mesoscale UM5.5 upgrade: PMSL differences Jorge Bornemann UM5.5 UM5.3 12Z on 22/02/2003 (T+36)

20 Page 20© Crown copyright 2004 Targeted moisture diffusion  Model failures due to grid point storms can cause Operational products to be delayed  Standard procedure is to re-run the forecast using a shorter timestep (e.g. 6 mins instead of 7.5 mins for the NAE)  We could use a shorter timestep all the time but it is more costly in terms of computer resources/run time  Targeted diffusion has helped reduce grid point storm failures by 65% (comparing 2003 with 2004).

21 Page 21© Crown copyright 2004 North Atlantic-European Model (NAE)

22 Page 22© Crown copyright 2004 Greenland – Valley cooling problem  Low values of theta caused model to crash (<100K !)  Cold spots confined to certain locations (valleys) in Greenland and Northern Canada  Forced to reconfigure from Global 6 times last Winter…

23 Page 23© Crown copyright 2004 Greenland – Cross section across valleys Chris Smith, Nigel Wood  Investigations revealed that the problem was present in no physics runs  Implication: a numerical instability in the dynamics  Runaway cooling occurs when the Courant number falls below a critical threshold:  C < C_crit (N, Δh) Δh is valley depth

24 Page 24© Crown copyright 2004 Alps – Cold spot in Valle D’Aosta Sam Smith, Andy Malcolm  Similar problems were encountered in 2km resolution modelling of MAP case studies  Theta advection uses non-interpolating Semi Lagrangian in the vertical  Mod to use full 3D SL theta advection with strict monotonicity cures the problem  Overall model stability still remains an issue

25 Page 25© Crown copyright 2004 NAE upgrade 22/09/04  A clear improvement to the NAE performance as a result of a package of changes to the UM and the data assimilation system  Introduction of additional observations (MOPS, local ATOVS and Meteosat rapid scan winds).  3-hourly assimilation cycle (previously 6-hourly)  Retune of the forecast error statistics  Revised orography ancillary file  Increased Gravity Wave Drag at the surface  Operational status from 22/09/04

26 Page 26© Crown copyright 2004 ATOVS data coverage Brett Candy QY06 01/10/04 RTTOV-5 + ATOVSG RTTOV-7 + ATOVSL Blue = NOAA16 Red = NOAA15

27 Page 27© Crown copyright 2004 NAE performance relative to Global & UK Mes Wind Cloud RMSE against Lead Time 18/08/2004 – 17/09/2004 Red = NAE Green = Global Blue = UK Mes

28 Page 28© Crown copyright 2004 NAE performance relative to Global & UK Mes Jorge Bornemann

29 Page 29© Crown copyright 2004 NAE future plans  Reduced domain - Winter 2004  38 levels ozone - Winter 2004  Physics changes (Microphysics, Boundary Layer, Prognostic cloud + condensate, Convection…) as per Global - Spring 2005  Saharan Albedo - Spring 2005  Use of 9 surface tiles (currently 1) - Spring 2005  12km horizontal resolution - Spring 2005  Replace U.K Mesoscale model

30 Page 30© Crown copyright 2004 NAE future plans  Nimrod soil state model for the U.K radar area (currently reset to climatology once a week) - Spring 2005  Full resolution AMSU-B - Summer 2005  Ensembles - Summer 2005  70 levels - Summer 2005  Use of soil level increments from screen level data outside the U.K radar area - Winter 2005/2006  4DVAR (currently 3D-VAR) - Winter 2005/2006

31 Page 31© Crown copyright 2004 NAE – reduced domain from Winter 2004

32 Page 32© Crown copyright 2004 NAE LAMEPS Alberto Arribas and Neill Bowler Global  Run to T+72  N144 (~ 90 km) NAE LAMEPS  Run to T+36  20 km  Limited Area Model Ensemble Prediction System  Focus on short-range (up to 3-days)  Model run daily using the 06Z and 18Z analysis  18 members (each one paired with a Global member)  Initial Condition perturbations: ETKF (u,v,q,T,P – all levels)  Lateral Boundary Conditions from the Global  Stochastic physics

33 Page 33© Crown copyright 2004 Falklands CAMM configuration Glenn Greed  Falklands:  172x130 grid points (~12km) and 38 levels.  Assimilation of observations, INCLUDING station temperature and RH.  18z forecast run to T+48.

34 Page 34© Crown copyright 2004 U.S.A test CAMM (17km) – Hurricane Ivan Glenn Greed

35 Page 35© Crown copyright 2004 TRMM Rain 09Z, GOES-12 IR 0745Z Glenn Greed

36 Page 36© Crown copyright 2004 Hurricane Ivan – Global forecast Glenn Greed

37 Page 37© Crown copyright 2004 INM collaboration - 5 Km UM over Spain Jorge Bornemann  Resolution 0.05 degrees (~5 Km)  606x430 grid boxes  38 levels  Rotated grid

38 Page 38© Crown copyright 2004 Spain 5Km model. 10m Winds Jorge Bornemann Mistral and Levante sensibly captured 18Z 05/01/2004 (T+18)

39 Page 39© Crown copyright 2004 Supercomputing plans Paul Selwood  Currently have two sets of 15 SX6 nodes split over two computer halls  These will be combined to form a 30 node sx6  15 new SX6X nodes (a.k.a SX8) - Summer 2005  Each SX8 node is twice as powerful as a SX6 node  Double the computing power will enable the planned increases in resolution and NAE 4D-VAR to go ahead

40 Page 40© Crown copyright 2004 Summary 2004  Balkans model withdrawn  All operational models ported to the SX6 and upgraded to UM6.0 (April)  Satellite upgrade to the Global model (May)  NAE upgrade (September)  4D-VAR in Global (October)  Falklands model (October)  Reduced NAE domain (November)

41 Page 41© Crown copyright 2004 Summary of plans 2005  70 levels in all models  Withdraw Stratospheric model  40km Global model  Physics changes in all models  Introduce Global and Limited Area Ensembles  12km NAE model  Withdraw U.K Mesoscale model  Introduce 4km UK model

42 Page 42© Crown copyright 2004 Questions & Answers


Download ppt "Page 1© Crown copyright 2004 Unified Model Developments 2004 Mike Bush NWP Met Office."

Similar presentations


Ads by Google