A presentation to the UNFCCC workshop on

1. PRECISProviding REgional Climates for Impact StudiesThe Hadley Centre regional climate modelling system A presentation to the UNFCCC workshop on non-Annex 1 national communication preparation guidelines by Richard Jones, Met Office Hadley Centre, UK 8 April 2003

2. Outline • Background: Motivation and PRECIS overview • PRECIS components and their application • Future climate scenarios available from PRECIS • Applying PRECIS in impacts assessment • Limitations of PRECIS and future developments

3. Motivation • UNFCCC requirement to assess national vulnerability and plans for adaptation • UNFCCC requirement to submit National Communications • Both need estimate of impacts • Impacts need detailed scenarios of future climate • Scenarios are best produced locally, using expert knowledge and increasing ownership

4. Predicting impacts

5. Who is PRECIS for? • Government scientists from less developed countries involved in vulnerability and adaptation studies • A regional model’s domain usually encompasses several countries, so it is hoped that neighbouring countries will collaborate to produce ensembles • It is hoped to draw on local resources, such as expertise in local climate

6. Who funds PRECIS?

7. How fast does it go? Hardware requirements • PC running under the Linux operating system • Memory : 512MB minimum; 768MB recommended • Minimum 60GB disk space + offline storage for archiving data • Simulation speed proportional to chip speed • T3E (supercomputer) - 1.5 months (36 Processors) • PC (Intel P4 2.8 GHz) - 4.5 months 30 year integration, 100x100 grid points

8. PRECIS: PC system components Domain Scenario Period Diagnostics Run PRECIS

9. PRECIS components: full list • User-interface to set up RCM experiments • The latest Hadley Centre RCM • Data-processing and graphics software • Boundary conditions from latest Hadley Centre GCM • Training course and materials • PRECIS website and helpdesk

10. What is a Regional Climate Model? • Comprehensive physical high resolution climate model that covers a limited area of the globe, usually including the atmosphere and land surface components of the climate system, and containing representations of the important processes within the climate system (e.g., cloud, radiation, rainfall, soil hydrology).

11. Regional Climate Models (RCMs) Limited area models driven at the boundaries by GCM observed boundary data. Resolution of 50km

12. Boundary conditions • Requests through • PRECIS website • helpdesk

13. Training course and supporting material • Training in the use of PRECIS will focus on: • Background science including uncertainties • Interpretation of PRECIS results by regional experts • Construction of regional climate change scenarios • Building capacity in countries/regions using PRECIS • PRECIS will be supplied with: • a workbook covering the background science, system description and the uses and limitations of PRECIS • a technical manual explaining technical details about the system and how install and to use it

14. Support and follow-up • Helpdesk • email, phone • web-based discussion • Website • news • updates • datasets • resources • Collaboration/workshops

15. Applications of RCMs • Regional detail when simulating current climate • Realistic detail in climate change predictions • Resolution of islands, smaller countries e.g. Italy • Realistic simulation of extreme events • Provides comprehensive data for impact models

16. WINTER PRECIPITATION OVER BRITIANObserved, and simulated with RCM and GCM

17. SIMULATION OF A TROPICAL CYCLONEin the PRECIS regional climate model Global climate model Regional climate model

18. WINTER DAILY RAINFALL OVER THE SW CAPE, SOUTH AFRICA SW Cape winter rainfall: Observed - red, GCM - green, RCM - blue <0.1 0.1-5 5-20 20-30 30-40 >40 mm/day

19. CHANGES IN MONSOON PRECIPITATIONbetween the present day and the middle of the 21st century Global climate model Regional climate model

20. SUMMER TEMPERATURES in the 2080scompared to the present day, due to A2 emissions Global climate model Regional climate model Climate on islands changes very differently to the surrounding Mediterranean Sea, and can only be predicted using an RCM

21. Future climate scenarios available from PRECIS • PRECIS can provide: • climate scenarios for any region • an estimate of uncertainty due different emissions • an estimate of uncertainty due to climate variability • Data available from PRECIS • comprehensive for atmosphere and land-surface • grid-scale box average quantities • maximum time resolution one hour

22. CO2 EMISSIONS PROFILESunder IPCC SRES scenarios Source: IPCC

23. GLOBAL TEMPERATURE RISE due to four SRES emissions scenarios

24. Applying PRECIS in impacts assessments • Obtain current state from impacts model via: a) observed data e.g. as used in model validation b) RCM control data • Obtain future state from impacts model using: • RCM climate changes (in means, variability, etc) applied to observed data (compare with a) • RCM future climate data directly (compare with b)

25. BAY OF BENGAL CYCLONEsimulated by the PRECIS regional climate model Resulting storm surge simulated using the Proudman Oceanographic Laboratory model

26. CHANGE IN ANNUAL SURFACE RUNOFFbetween today and the 2080s, for A2 emissions Southampton University hydrological model

27. Current limitations of PRECIS • 10 year simulations take a month or more • It is a model hence imperfect, i.e. uncertainty due to use of only one RCM is not captured • Uncertainty due to imperfect driving data (i.e. from only one GCM) is not captured • Resolution of 50km or 25km insufficient for some impacts applications • Coastal or marine impacts have to be inferred (e.g. storm surges)

28. PRECIS: treatment of uncertainties • PRECIS accounts for uncertainties due to: • Future emissions - uses 4 SRES scenarios • Natural variability - uses initial condition ensembles • PRECIS does not account for uncertainties due to: • The conversion of emissions to concentrations - carbon cycle or chemistry (except sulphur cycle) not represented • Uncertainty in the response of the climate system - only boundary conditions from 1 GCM are used • Uncertainty in the detailed climate change - only one RCM is used

29. CHANGE IN S ASIA SUMMER RAINFALL with PREDICTED BY NINE GCMs (A2 emissions) A2 emissions scenario

30. % CHANGE INWINTERPRECIPITATION

31. REPRESENTATION OF THE PHILIPPINESWITH DIFFERENT MODEL RESOLUTIONS 25km RCM resolution 50km RCM resolution GCM 300km resolution

32. FUTURE DEVELOPMENTS • Continuously upgraded to new processors • Ability to run PRECIS RCM from different GCMs • at least two to be added this year • relevant cooperation from GCM centres being sought • Intercomparisons of all RCMs being organised • No plans for PRECIS to incorporate other RCMs • Resolution of model being improved to 10km • RCM with ocean component being built

33. Final remarks • You can contact us via: • Email: precis@metoffice.com • Tel: +44 1344 856885 • Fax: +44 1344 854898 • Web-site for information on PRECIS • www.hadleycentre.com/models/PRECIS.html