Presentation on theme: "COSMO User Seminar 2012 Offenbach, 8 March 2012"— Presentation transcript:
1 COSMO User Seminar 2012Offenbach, 8 March 2012Performance evaluation and climate projections over Sub-Saharian Africawith COSMO-CLMPaola Mercogliano, CIRA and CMCCEdoardo Bucchignani, CIRA and CMCCMyriam Montesarchio, CMCCAlessandra Zollo, CMCC
2 Short summary of activity shown at CLM Assembly 2011 The CLUVA project 1. OutlookIntroductionShort summary of activity shown at CLM Assembly 2011The CLUVA projectThe domains simulatedList of simulationsThe West domain: validation and climate projectionsThe Lower East domain: validation and climate proj.Conclusions
3 2. CLUVA – Climate change and urban vulnerability in Africa Project Co-ordinator: AMRA, Center of Competence in the field of Analysis and Monitoring of Environmental Risk, ItalyThe project objective is to develop methods and knowledge to be applied to African cities, to manage climate risks, to reduce vulnerabilities and to improve their coping capacity and resilience towards climate changes. The project will explore the issues of climate change vulnerability, resilience, risk management and adaptation in selected African cities with local partners.Task 1.1: Model projection of climate change (Leader: CMCC)The aim is to set up methods and work out probabilistic scenarios of climate change affected hazards having a resolution that fits for regional and urban systems (for the 5 selected cities) and related uncertainties. More detailed aims are:To produce downscaled regional climate scenarios (IPCC scenarios: RCP4.5 and RCP8.5) for selected African areas surrounding the African cities of interest, at high resolution (about 8 km).To produce very high resolution projection (about 1-2 km) for the climate of some African cities using specific and accurate statistical techniques
4 3. Areas of interest for CLUVA 1950-2050 Spatial Resolution: 8 kmEAST Domains:U (34.4 – 42.9 E; 6.1N – 12.5N)120 x 90 grid pointsL (34.5 – 41.3 E; 11.8S – 2.1S)95 x 135 grid pointsWEST Domain:(18 W E; 3.3 – 16.8 N)465 x 190 grid pointsSt.Louis (16.5 W, N) Ougadougou (1.55 W, N)Douala (9.71 E, N)Addis Abeba (38.75 E, 9.02 N)Dar es Salaam (39.27 E, 6.82 S)
5 4. Orography of the three areas WestUpperEastLowerEast
6 5. Details of the Numerical simulations 8 km resolutionSupercomputer used:Cluster of 30 IBM P575 nodes (32 cores per node)Driving data: CMCC-MED 80 km resolutionModel version: cosmo_090213_4.8_clm13Time step: 40 sec.Numerical scheme: Runge-Kutta 2-time level HE-VI integrationValidation: CRU data and observed datasets for the 5 cities.
7 6. List of simulations Scenario A1B West domain 1970- 2065 Scenario RCP 4.5 Lower East domain Scenario RCP 4.5 Upper East domain (*)Scenario RCP 4.5 West domain Scenario RCP 8.5 Lower East domain Scenario RCP 8.5 Upper East domain (*)Scenario RCP 8.5 West domain (*): completed, but not yet post processed.
8 7. Mean temperature bias with CRU (COSMO-CRU) DJFCold bias between -1 and -2 degrees.In the north part, up to -5JJAHot bias between 2 and 3 degrees.Higher values in the west part.
9 8. Mean precipitation (mm/month) bias with CRU DJFUnderestimation of about 25% in the south coastal area.Good agreement in the other parts.JJAA strong wet bias is registered in the south coastal area.Underestimation in other parts.
10 9. Seasonal cycle of temperature (COSMO vs Observations) St. LouisMaxApplied Bias correction (Sperna et. Al 2010):: 30-year daily average temperatureMeanMaximum bias in April (20C)
11 10. Seasonal cycle of temperature (COSMO vs CRU) DoualaOuagadougouMaxMean
12 11. T2m variation : future (2021-2050) vs past (1971-2000) A1BDJFGeneral increase of temperature, up to 2.4o; it is more evident in winter.JJA
13 12. T2m variation : future (2021-2050) vs past (1971-2000) RCP4.5DJFLess evident increase of temperature, especially in summer.In winter, significant increase in the northern part.JJA
14 13. T2m variation: future (2021-2050) vs past (1971-2000) RCP8.5DJFLarger increase of temperature in summer with respect the other scenarios.In winter, the increase is evident only in the northern part.JJA
15 14. Precipitation variation: future (2021-2050) vs past (1971-2000) A1BDJFThere is a big difference between winter and summer.In winter, there is a slight decrease of precipitation, while in summer there is a general increase with some exceptions.JJAmm/month
16 15. Precipitation variation: future (2021-2050) vs past (1971-2000) RCP4.5DJFThere are differences between winter and summer.In winter, there is a general increase of precipitation, while in summer there is a behavior similar to A1BJJA
17 16. Precipitation variation: future (2021-2050) vs past (1971-2000) RCP8.5DJFIn winter, there is a general increase of precipitation, similar to RCP4.5In summer there is a behavior similar to A1B and RCP4.5JJA
18 17. T2m trend (A1B vs RCP 4.5)OuagadougouSt.Louis
19 18. Precipitation trend (A1B vs RCP 4.5) OuagadougouSt.Louis
20 19. Mean temperature bias with CRU (COSMO-CRU) In winter, there is a cold bias between -2 and -3 degrees.In some parts, up to -5In summer , there is a hot bias between 1 and 2 degrees.DJFJJA
21 20. Seasonal cycle of temperature (COSMO vs CRU) Dar es SalaamMaxIn winter , there is a cold bias especially evident in the maximum values of daily temperature.Mean
22 21. T2m variation: future (2021-2050) vs past (1971-2000) RCP4.5In winter, two different areas are visible, but both characterized by an increase of temperature.In summer, a general increase of 1.5o C is evident.DJFJJA
23 22. T2m variation: future (2021-2050) vs past (1971-2000) RCP8.5With this scenario, the increase of temperature is more uniform and evident with respect to RCP4.5.DJFJJA
24 23. Precipitation variation: future (2021-2050) vs past (1971-2000) RCP4.5In winter, we register reductions in the central part of the domain and increases along the coast.In summer, a general reduction is evident.DJFJJA
25 24. Precipitation variation: future (2021-2050) vs past (1971-2000) RCP8.5In winter, similar behavior as RCP4.5, but less evident increase along the coast.In summer, similar behavior as RCP4.5.DJFJJA
26 25. ConclusionsNumerical results related to the simulation of the climate of the west and the east lower domain at high resolution have been shown.for the west domain: cold bias in winter, and hot bias in summer with respect to CRU. Better agreement registered with observed data provided by project partners. Quite good agreement of precipitations in winter, while in summer there is a strong bias;for the east lower domain: the temperature is underestimated in winter and overestimated in summer with respect to CRU; better agreement with observed data, especially in summer;for the west domain: in the future, the temperature is projected to increase, especially in winter with all the three scenarios; in winter the precipitation is projected to slightly increase by RCP4.5 and 8.5; in summer is projected to increase by all the scenarios.for the east lower domain: in the future, the temperature is projected to increase by both the scenarios, especially in winter.