P. Bessemoulin & J.P. Céron Météo-France Jean-Pierre.Ceron@meteo.fr

1. Technical Conference on « Changing Climate and Demands for Climate Services for Sustainable Development » Research Needs for Seasonal to Inter-annual Climate Prediction P. Bessemoulin & J.P. Céron Météo-France Jean-Pierre.Ceron@meteo.fr Susesi Hotel – Antalya – Turkey 16 –18 February 2010

2. Outline • LRF landscape • Capabilities and needs • The LRF and Application framework • How to improve Climate Products and Services ? • Improvement of Global Climate Models • Large Scale information • Regional and National level • Climate impacts on sectorial activities and decision making • Conclusion Technical Conference Antalya – 16 to 18 february 2010

3. Capabilities and Needs • - WCRP Seasonal Prediction Workshop, Barcelona Spain, 4-7 June 2007 (WCRP Position Paper on Seasonal Prediction, 2008: WCRP Informal Report No. 3/2008; Ben Kirtman and Anna Pirani, 2009: The State of the Art of Seasonal Prediction: Outcomes and Recommendations from the First WCRP Workshop on Seasonal Prediction. BAMS, Vol. 90, issue 4, pp 455–458). • World Modelling Summit for Climate Prediction, Reading, UK, May 6-9, 2008 (Workshop Report WCRP No. 131; and Palmer and Shukla (2008): Advances in Modelling and Seamless Prediction (WMO/TD-No. 1458). ) • Review of the World Climate Research Programme (WCRP) (Feb. 2009) : Report from an ICSU-WMO-IOC-IGFA Review Panel • Review of the World Climate Programme (WCP) and Climate Agenda (Feb. 2009): http://www.wmo.int/pages/prog/wcp/cca/documents/Doc5reviewWCPandclimateagenda.pdf • WMO EC-RTT Report on the Challenges and Opportunities in Research on Climate, Weather, Water and Environment (WMO/TD-No. 1496) (June 2009). • WCC-3 white papers/presentations at Sessions on   « Advancing climate prediction science » and « Seasonal-to-interannual climate variability » (Sep. 2009) Technical Conference Antalya – 16 to 18 february 2010

4. How to improve Climate products and services ? • Improvements of Global Climate models • Resolution (Horizontal and vertical) • Physics / Parameterizations • Additional sources of predictability • Soil moisture : impacts notably on intraseasonal signal and Summer season • Snow : Potential impact on Indian Summer monsoon, Winter AO/NAO, and seasonal predictability • Stratosphere : Polar stratosphere=> Influence of ENSO, QBO, blocking events over Northern Atlantic and Northern Pacific. Equatorial stratosphere (QBO) => impact on tropical and extratropical climate. TropicalStratosphere/ Troposphere interaction => impact on extratropical climate. Technical Conference Antalya – 16 to 18 february 2010

5. Modeling issues • Resolution (both vertical and horizontal) • Current resolution for operational models (GPCs) * Pretoria information not yet available Technical Conference Antalya – 16 to 18 february 2010

6. How to improve Climate products and services ? • Large Scale information • MME issues • Circulation regimes / Modes of variability • Other parameters to be investigated (TC, Number of days, SPI, Extreme Events, Psi and Khi parameters, … ) • Climate trend and Seasonal forecast • Prediction of the predictability • Intraseasonal information (including MJO, monthly desaggregation of LRF, … ) • … Technical Conference Antalya – 16 to 18 february 2010

7. MME issues • MME intiatives : • Operational MME : Euro-Sip, IRI, APCN • Lead-Centre for MME (joint initiative from KMA and NCEP under the umbrella of WMO) Technical Conference Antalya – 16 to 18 february 2010

8. MME issues • Is Multi-model approach better than Single model forecast ? Weigel et ali, , 2008, QJMRS • RPSS maps – DEMETER experiment • 1960-2001 – T2m – JJA season • model S2 b) model GS • c) MME equal weights d) MME optimal weight (IGN method) Still some work to do on the best combination (e.g. coupled, 2 tiered, all, optimal combinations) and the evaluation of MME products Which products (Large Scale, global outlook, …) ? Technical Conference Antalya – 16 to 18 february 2010

9. MME issues Weigel et ali, 2008, QJMRS • Is Multi-model approach better than Single model ? comparison of grid points RPSS : Multi-Model (IGN) against Single Models MME not necessarily the best for local applications (improvements versus operationnal constraints) Regions where MME (IGN method) outperforms single model forecasts Technical Conference Antalya – 16 to 18 february 2010

10. Atmospheric Circulation Regimes Chabot et al. – EMS-ECAC conference - 2008 Summer Regime (JJA -1st of May Initialisation – Z500) NCEP Model 1 Model 2 Atl.Low/NAO+ S-Blocking Atl.Ridge NAO- Technical Conference Antalya – 16 to 18 february 2010

11. Atmospheric Circulation Regimes • Model 1 shows a better sensitivity to ocean than Model 2 despite this is not reflected in the scores Oceanic Precursors of winter regimes Model 1 Model 2 Consistent with Greatbatch et al., 2004 NINO NINO NAO- NINA NATL Consistent with Sutton, 2001 NAO+ Consistent with Kushnir et al., 2002 Atlantic Ridge Newfoundland Pattern Consistent with Rodwell, 2002 Horse Shoes shape + NINA Blocking Horse shoes shape - NINO Favoured when : Not favoured when : Technical Conference Antalya – 16 to 18 february 2010

12. Other Large Scale Parameters New Model Diagnosis and associated evaluations (e.g. Stream function and Velocity Potential) JFM 2010 forecasts In regions where the predictability is quite low, it becomes crucial for the use of climate information to give information on the predictability of individual years or seasons (especially in mid-latitudes) and expected teleconnections Technical Conference Antalya – 16 to 18 february 2010

13. Impact of Climate Trend on the Seasonal Forecast Model 1 Model 2 JJA Trend Ensemble Mean Technical Conference Antalya – 16 to 18 february 2010

14. How to improve products and services ? • Regional and National Levels • Improving Regional Climate Modelling • Downscaling and tailoring (statistical vs dynamical) • Spatial and temporal • Best practices (software, guidance, …) • Large Scale influence at regional and national scale • … Technical Conference Antalya – 16 to 18 february 2010

15. Downscaling Methods State of the Climate system (ocean-atmosphere + Cryosphere-Biosphere) Large Scale Information GCM : Global Climate Model RCM :Regional Climate Model Statistical models Statistical models (PP or MOS) NH models User’s models User’s models Useful Forecast at smaller scales Technical Conference Antalya – 16 to 18 february 2010

16. Downscaling Methods First step : Intermediate information on SYMPOSIUM zones • Downscaling challenge for applications : from 2°5 to 8 km Evaluation and propagation of uncertainty DEMETER Precipitation Second step : downscaling Downscaling on ISBA mesh - 8km Cumulated rain in mm over March-April-May 1998 SAFRAN Reference Technical Conference Antalya – 16 to 18 february 2010

17. Time Downscaling • MJO forecasts Linkage with resolution and physics : Kang – 2007 – APCC symposium Technical Conference Antalya – 16 to 18 february 2010

18. Downscaling methods • Best Practices • Softwares (developed on best practices considerations, needs of specifications and qualification) • Guidances (joint effort of WCRP and WCP) to the benefit of RCOFs, RCCs, NMHS, NCCs, … Technical Conference Antalya – 16 to 18 february 2010

19. How to improve products and services ? • Climate influence at regional and national scales • Impact of external forcings • Circulation regimes / modes of variability • Teleconnection patterns (and their representation in GCMs) • Other parameters to predict ( Number of rain or dry days, length of the rainy season, SPI, … ) • Predicting other components of the Climate system (Hydrology notably) • … Technical Conference Antalya – 16 to 18 february 2010

20. How to improve climate products and services ? • Hydrological seasonal forecats : ensemble riverflow forecast 1 state 1 state 9 runs 9 Céron et al. – ASL 2010 – DOI: 10.1002/asl.256 Technical Conference Antalya – 16 to 18 february 2010

21. How to improve products and services ? • Hydrological seasonal forecats : ensemble riverflow forecast Ensemble mean compared to the SIM reference on the training file (period 1979-2001) – Spring period (MAM) SWI is particularly relevant for Agriculture applications and drought monitoring Correlations :Soil Wetness Index Céron et al. – ASL 2010 – DOI: 10.1002/asl.256 Technical Conference Antalya – 16 to 18 february 2010

22. How to improve products and services ? • River flow forecasts : Probabilistic / Deterministic forecast quite interesting Céron et al. – ASL 2010 – DOI: 10.1002/asl.256 Hydrological components can have a higher predictability than the atmospheric parameters (partly related to slowly varying forcings like snow cover) Scores for 4 river catchments and spring period (MAM) Technical Conference Antalya – 16 to 18 february 2010

23. How to improve products and services ? • Climate impact on sectorial activities and decision making • User oriented evaluations (e.g. use and impact of use of LRF, socio-economic benefits, …) • Use of seasonal forecasting information (decision making, evaluation, …) • Seamless use of Climate information • Communication to the users including uncertainty and vulnerability assessments • Assessment of climate impacts • Climate “awareness” • … Technical Conference Antalya – 16 to 18 february 2010

24. Forecst / Obs T- T0 T+ T- a b c O- T0 d e f O0 T+ g h i O+ F- F0 F+ User oriented evaluations User oriented evaluation(values): based on Hits and Misses and users cost functions The basic information is included within the LRF-SVS level 3 (contingency tables to be adapted ?) Close collaboration with the user sectors (economical models, …) Technical Conference Antalya – 16 to 18 february 2010

25. Use of Seasonal Forecasts Evaluation of the users Decision Making chain Julie & Céron Elements for Life - 2007 • Evaluation over the training period (1979-2000) : • energy production optimisation up to 35-40%, • artificial flood, allowing a surface of 50 000 ha for recession culture, guaranteed 4 years out of 5 compared to 1 out of 5 in natural regime • water resource saving around 10% But in the real life ? Technical Conference Antalya – 16 to 18 february 2010

26. Highlights • Modelling issues • Improvement of Global Climate models • Additional sources of predictability • Large Scale Information • MME issues • Circulation regimes and modes • Other LS parameters • Impact of climate trend on Seasonal forecasting • Regional and National levels • Space and Time downscaling • Other component of the climate system • Climate impact on sectorial activities and Decision Making • User-oriented evaluation • Use of Climate information Technical Conference Antalya – 16 to 18 february 2010

27. Conclusion • Research needs on LRF • Still a lot of work to achieve on both WCRP and WCP sides ! • Needs of better and sustainable linkage between Research, Operations and Users (which mechanism ?) • Climate Services perspectives (GFCS) • Priorities for the next intersession period (e.g. Downscaling effort, MME issues, GCMs improvements, … ?) • … • A number of cross-cutting themes between WCRP and WCP • WCRP / WCP coordination and joint efforts (especially between WGSIP and OPACE 3) • Inter-Commission Task Team on Seasonal to Inter-Annual forecasts (WGSIP / OPACE 3 / CBS ET-ELRF) ? • … Technical Conference Antalya – 16 to 18 february 2010

28. WORLD METEOROLOGICAL ORGANIZATION Senousi Hotel – Antalya Turkey Thank you for attention Research needs for seasonal forecasting and its applications Technical Conference P. Bessemoulin & J.P. Céron Météo-France / Direction of Climatology Jean-Pierre.Ceron@meteo.fr

29. Use of Seasonal Forecasts Seamless use of Climate information • Continuum of information on both space and time scales : • Best compromise between users’ needs and science and related feasible products • Consistency between use of information and information • Needs of information on the use of the products (actions/decisions, decisional calendar, critical time scales) Range extension Provision of Climate Information and Services should be an Action Driven Process Technical Conference Antalya – 16 to 18 february 2010

30. The LRF and Application framework Global Level Monitoring & Forecast (GPCs, LCs, GDC, GMC, …) Regional Level (RCC , RCOF, RCW, …) MEDIA Regional Users International Partners Regional Partners National Partners Users (National) Water ressources Agriculture Energy Health … National Organisation & NGO National Level (NMHS, NCC, NCOF, ...) MWG MEDIA Technical Conference Antalya – 16 to 18 february 2010

31. Downscaling Methods • Purely Dynamical and Statistical/Dynamical methods give quite comparable results Palmer et al, 2004, BAMS (Demeter paper) Technical Conference Antalya – 16 to 18 february 2010

32. Use of Seasonal Forecasts Implementation of the climate information into the user decision making chain and evaluation Dispatching of the forecast to Dakar desagregated by month and for the region of interest at the beginning of August SON Forecasts issued in Toulouse by the end of July. Merging informations from the water management and the seasonal forecast Choice of the best strategy taking into account the concurent uses of the water. Technical Conference Antalya – 16 to 18 february 2010

33. Use of Seasonal Forecasts Implementation of climate information into the users’ decision making chain and evaluation Use of Presao forecast by IFRCC Technical Conference Antalya – 16 to 18 february 2010

34. Atmospheric Circulation Regimes Euro-Sip models 6 9 8 False Alarme 6 10 3 Hits 8 8 6 6 7 Chabot et al. – EMS-ECAC conference - 2008 7 5 8 8 4 15 8 7 6 5 6 Technical Conference Antalya – 16 to 18 february 2010

35. Atmospheric Circulation Regimes Euro-Sip models 6 9 8 False Alarme 6 10 3 Hits 8 8 6 6 7 Chabot et al. – EMS-ECAC conference - 2008 7 5 8 8 4 15 8 7 6 5 6 Technical Conference Antalya – 16 to 18 february 2010

36. Circulation Regimes and Downscaling Mean Anomalies • Forecast Mode and use – Winter 2009 forecasts Increased Occurrence of NAO – regimes Min Temperatures / Extreme Rainfall Technical Conference Antalya – 16 to 18 february 2010

37. Forecast Z500 JJA 2008 Impact of Climate Trend on the Seasonal Forecast Trend JJA Provision of Climate forecasts at seasonal scales : (Seasonal + Trend) or Seasonal and Trend separately ? Technical Conference Antalya – 16 to 18 february 2010

38. LRF Context • Operationnal LRF at global scales • GPCs or GPCs-like centres • Provision of MME products (Euro-Sip, IRI, APCC) • WMO Lead-Centres (LRF-MME and SVS-LRF) • Needs of LRF products • Reduction of vulnerability to the current Climate Variability • Assessment of the value and success stories demonstrating the usefulness of LRF products. • LRF and CC issues • Coping with the current Climate Variability is the first step to CC adaptation • Lessons learnt from LRF useful for CC issues (tools, methods, user liaison, …) • WCC3 : from products to Climate Services • Needs to move from products to Climate Services tailored to users’needs • LRF frameworkconsistent with GFCS • Prioritary domains (water resources, food security, health, …) Technical Conference Antalya – 16 to 18 february 2010

39. The LRF and Applications components • Global level • Global Climate Models • Description of the climate system (notably initial state and different components) • influence of slowly varying forcings on Climate at global scale (including teleconnections) • Climate impacts on sectorial activities and decision making • Regional Level • Regional Climate Models • Downscaling and tailoring • Climate influence at regional scale (idem) • Climate impact on sectorial activities and decision making • National Level • Downscaling and tailoring • Climate influence at national scale (idem) • Climate impact on sectorial activities and decision making Technical Conference Antalya – 16 to 18 february 2010

40. Use of Seasonal Forecasts • How to merge Information • from different sources • Consensus methods Technical Conference Antalya – 16 to 18 february 2010

41. Modeling issues Kang – 2007 – APCC symposium • Resolution (horizontal) For Seasonal Forecasting • Some improvements from 300 to 100 km (mean climate, scores) • Benefits less clear from 100 to 20 km Forecasting extremes MJO Technical Conference Antalya – 16 to 18 february 2010

42. NAO EOF index PNA grid cell index Additional sources of predictability Douville, 2009, Geophys. Res. Lett. doi :10.1029/2009GL039334 Control ensemble Nudged ensemble • Stratosphere Technical Conference Antalya – 16 to 18 february 2010

43. Additional sources of predictability A.C. Mayock et al., 2009, Climate Dynamics, doi :10.10007/s00382-009-0665-x • Stratosphere • Poor representation of stratospheric circulation • Presently no discernable predictability in the extratopical stratosphere • Robust large scale response (weakened Polar Vortex, NAM -) • Impact of resolution • Impact of physics (GWD, Convection, ..) • Modelling challenge ? Z500 Composites for the 10-30 days following the 7 largest peak amplitude « warming » events Technical Conference Antalya – 16 to 18 february 2010

44. Modeling issues • Physics : • No independance between the horizontal and vertical resolution andthe physics • No independance between the phenomenum of interest, the resolution and the physics • Generally, the finer the resolution, the more refined the physical package • For operations, balance between the horizontal resolution, vertical resolution, physical package and computing resources Technical Conference Antalya – 16 to 18 february 2010

45. Modeling issues Kang – 2007 – APCC Symposium • Resolution (horizontal) Technical Conference Antalya – 16 to 18 february 2010

46. Additional sources of predictability • Surface conditions • Soil moisture (impacts notably on intraseasonal signal and Summer season) • Douville 2009, Koster et al. 2010 • Snow • Potential impact on Indian Summer monsoon : Robock et al. 2003, Fasullo 2004 (Obs.), Ferranti and Molteni 1999 (GCMs), Peings and Douville 2009 (CMIP3) • Potential impact on Winter AO/NAO : Qian and Saunders 2003, Cohen 2007 (Obs) Gong et al. 2003, Fletcher et al. 2007, Fletcher et al. 2009 (GCM s), Hardiman et al. 2008 (CMIP3) • Potential impact on seasonal predictability : e.g. Cohen and Fletcher 2007 (Statistical hindcasts), Orsolini and Kvamsto 2009, Douville 2009 (Dynamical « hindcasts ») Technical Conference Antalya – 16 to 18 february 2010

47. Additional sources of predictability • Stratosphere • Polar stratosphere=> Influence of ENSO (e.g. Ineson and Scaife 2009), QBO (e.g. Hamilton 1998, Thompson et al. 2002, Marshall and Scaife 2009), blocking events over Northern Atlantic and Northern Pacific (e.g. Martius et al. 2009). • Equatorial stratosphere (QBO) => impact on tropical (e.g. Giorgetta et al. 1999) and extratropical climate (e.g. Boer and Hamilton 2008). • Tropical troposphere => impact on extratropical climate (e.g. Jung et al. 2008). Technical Conference Antalya – 16 to 18 february 2010

48. NAO EOF index PNA grid cell index Additional sources of predictability Douville, 2009, Geophys. Res. Lett. doi :10.1029/2009GL039334 Control ensemble Nudged ensemble • Stratosphere influence Technical Conference Antalya – 16 to 18 february 2010

49. Northern Europe Temp. (K) Northern Europe Prec. (mm/d) Additional sources of predictability Douville, 2009, Geophys. Res. Lett. doi :10.1029/2009GL039334 Control ensemble Nudged ensemble • Stratosphere influence Technical Conference Antalya – 16 to 18 february 2010

50. MME issues • Is Multi-model approach better than Single model forecast ? BSSs – Demeter experiment 1958-2001 – T2m – all season Technical Conference Antalya – 16 to 18 february 2010