The THORPEX Interactive Grand Global Ensemble

1. The THORPEX Interactive Grand Global Ensemble David Richardson Met Office, Exeter

2. Contents The presentation covers the following sections • Global Interactive Forecast System concept • The THORPEX Interactive Grand Global Ensemble (TIGGE) • 1st TIGGE Workshop • Future plans • Links to Pacific Experiment

3. Traditional forecast system observations Assimilation Forecast users

4. Global Interactive Forecast System Forecaster runs ‘sensitive area’ prediction Initial risk from medium-range global ensemble Forecaster requests observations in sensitive area Forecaster requests high resolution regional ensemble Initiate and maintain links with civil protection agencies

5. Global Interactive Forecast System (GIFS) A concept for future weather prediction Global • Global participation, global application, global and regional models Interactive • observation-assimilation-forecast-user: all parts of system integrated, adaptive, interactive. Changes according to situation and user needs. We cannot say now what a future Global Interactive Forecast System will be – a goal of THORPEX is to determine this The development, evaluation and testing of a future GIFS will depend on results from all four components of THORPEX

6. THORPEX Interactive Grand Global Ensemble (TIGGE) • Framework for international collaboration in development and testing of ensemble prediction systems • Resource for THORPEX research projects • Component of THORPEX Forecast Demonstration Projects (FDPs) • A prototype future Global Interactive Forecast System • Initially develop database of available ensembles, collected in near-real time • Co-ordinate research using this multi-model ensemble data, including interactive aspects

7. TIGGE Workshop • Workshop: 1-3 March 2005, ECMWF • Address strategy to achieve TIGGE objectives • Focus on user-requirements and infrastructure needed to meet these • Produce outline plan and timetable • 60 participants from operational centres and universities worldwide • Report submitted to THORPEX Executive Board and International Core Steering Committee • www.wmo.int/thorpex/publications.html

8. TIGGE Workshop: aims Predictability science Real-world applications • Aim: Define user-requirement for TIGGE data • Users • Who? • What for? • How? • When? • Requirements • What data? • Format? • How to access? • Contributors NHMS academic End user ??? EPS 1 EPS 2 EPS n

9. TIGGE infrastructure Phase 1 Predictability science Real-world applications • Data collected in near-real time (via internet ftp) at central TIGGE data archives • Can be implemented now at little cost • Can handle current data volumes within available network and storage capabilities NHMS academic End user TIGGE Centre A TIGGE Centre B EPS 1 EPS 2 EPS n

10. TIGGE infrastructure Phase 2 Predictability science Real-world applications • Data distributed over several repositories • But keep efficient and transparent user access • Flexible – minimise data transfers • Needs substantial software development • Coordination with WMO Information System • Requires additional funding NHMS academic End user Portal to distributed (virtual) archive EPS 1 EPS 2 EPS n

11. Access and use of TIGGE data Aims for TIGGE data policy: • TIGGE data available to all users for research purposes (efficient approval for data access) • User-friendly interface for access to the central archives (including for subsets of ensemble data) • Promote open-source sharing of post-processing software (calibration, combination, decision-making) to maximise benefit for both researchers and end-users • Address issue of real-time access to data, in particular for demonstration projects and field experiments

12. TIGGE Plans • Phase 1: • Central TIGGE archives: ECMWF (NCAR, CMA) • For ECMWF: funded within existing resources • Technical plan: July 2005 • Initial infrastructure development: Jan 2006 • Early 2006: TIGGE data archives will begin collecting available ensemble contributions in near-real time • 2007-08: TIGGE available for THORPEX support to demonstration projects (IPY, Beijing 2008 Olympics regional EPS, Pacific THORPEX Experiment) • Phase 2: • distributed archive • Coordinate with WMO Information System plans • ECMWF will lead bid for FP6 funding

13. TIGGE and Pacific Predictability Experiment • Predictability studies – inter-comparison of different available ensemble systems • Are all models equally poor over W N America? • Are better models still relatively worse here than elsewhere? • Are analyses relatively worse over Pacific? • Does better use of satellite data improve performance? • Is predictability intrinsically low? • How important is model error?

14. TIGGE and Pacific Predictability Experiment • Predictability studies – inter-comparison of different available ensemble systems • Field campaign support • Real-time access to global TIGGE ensemble forecasts • Advance warning of potential significant events • Sensitive area predictions incorporated in TIGGE infrastructure (some SAP also directly use TIGGE ensembles) • Regional ensembles • Boundary conditions from global TIGGE ensembles • Regional ensembles into TIGGE archives • Co-ordinated inter-comparison of performance • Global TIGGE predictions of when to run regional/mesoscale ensembles

15. Northern hemisphere 500 hPa ACC • Impact of removing most in-situ observations • COMB • operational Met Office system • BASE • All satellite data • GUAN radiosonde • GSN land stations (pressure only) • Ocean buoy data (no ships)