European regional climate European regional climate change and the PRUDENCE change and the PRUDENCE

projectproject

Ole Bøssing ChristensenDMI

IPCC AR4 CH. 11 structure IPCC AR4 CH. 11 structure Jens H. Christensen (CLA)Jens H. Christensen (CLA)

Chapter 11 structure : Regional Climate ProjectionsLength:60 printed pages including all refs and figures, excl. FAQCLAs: Christensen and HewitsonLAs: Busuioc, Chen, Gao, Held, Jones, Kwon, Laprise, Magana, Mearns, Menendez, Räisänen, Rinke, Kumar, Sarr, Whetton

Executive summary (1-2 pages)

11.1 Introduction (3 pages)

11.1.1 The importance of regional projections

11.1.2 Summary of the TAR

11.1.3 Developments since the TAR

11.2 Assessment of Methods11.2.1 Generating regional information (5 pages)

11.2.1.1 AOGCM results11.2.1.2 High resolution AGCMs11.2.1.3 Nested RCMs11.2.1.4 Statistical downscaling11.2.1.5 Pattern scaling of climate model simulations11.2.1.6 Other methods11.2.1.7 Inter-comparison of methods

11.2.2 Quantifying uncertainties (3-4 pages)11.2.2.1 Sources of regional uncertainty11.2.2.2 Methodological developments

11.3 Regional Projections (30 pages)Details on following slides

11.4 Conclusions and discussion (1 page)

11.3 Regional Projections (30 pages)11.3.1 Introduction to regions and relationship to WGII regions (1 page) (Any sub-regions listed below may be further sub-divided if authors feel this is appropriate)(Length: nominally 3-4 pages each)11.3.2 Africa

Sahelian AfricaHorn of Africa / Arabian peninsulaEquatorial AfricaSouthern Africa

11.3.3 Mediterranean and EuropeMediterraneanCentral and northern Europe

11.3.4 AsiaCentral AsiaSouth AsiaEast AsiaSouth east Asia / Maritime continent

11.3.5 North America North America

11.3.6 Latin AmericaCentral America / CaribbeanNorthern South AmericaSouthern South America

11.3.7 Australia and New ZealandAustralia/New Zealand

11.3.8 PolarArcticAntarctic

11.3.9 Small Islands

Chapter 11 structure : Regional Climate Projections

Chapter 11 structure : Regional Climate Projections

BOX 11.1: Summary of AOGCM regional projections (2 pages) Consistent method across regions, & to include uncertainty

Probabilistic statements based on AOGCMs, in coordination with Ch 10

BOX 11.2: Common aspects of small scale climate change : High altitude (1 page)

BOX 11.3: Common aspects of small scale climate change : Coastal (1 page)

Table 11.1: Extremes (1 page)Summary table in collaboration with Ch 3,4,5,9,10 & WGII

FAQ

Proposed FAQ: a) Does this report say anything about what will happen in my back

yard?b) Will the weather become more extreme?c) How can I use regional information that is uncertain?

(Why are regional projections useful?) d) What’s downscaling?e) What’s wrong with extending recent regional trends?

IPCC WG1 IPCC WG1 scheduleschedule

PRUDENCE participantsPRUDENCE participants1. Danish Meteorological Institute, Copenhagen, DK2. CINECA, Bologna, IT3. Météo-France/CNRM, Toulouse, FRA4. Deutsches Zentrum für Luft- und Raumfahrt e.V., Weßling, GER5. Hadley Centre for Climate Prediction and Research, Met Office, Bracknell, UK6. Climate Research ETH (Eidsgenössische Technische Hochschule), Zürich, CH7. GKSS Research Center (Institute for Coastal Research), Geesthacht, GER8. Max-Planck-Institut für Meteorologie, Hamburg, GER9. Swedish Meteorological and Hydrological Institute, Rossby Centre, Norrköping, SWE10. Universidad Complutense, Madrid, SP11. Universidad Politecnica, Madrid, SP12. International Centre for Theoretical Physics, Trieste, IT13. Danish Institute of Agricultural Sciences, Foulum, DK14. Risø National Laboratory, System Analysis Dept., DK15. University of Fribourg, CH16. Finnish Environmental Institute, Helsinki, FIN17. University of Reading, UK18. University of Lund, SWE19. Centre International de Recherche sur l’Environnement et le Développement, SMASH, Paris, FRA20. Climate Research Unit, University of East Anglia, UK21. Finnish Meteorological Institute, Associated to FEI (No. 16), FINA. Norwegian Meteorological Institute, Blindern, NOB. Royal Dutch Meteorological Institute, De Bilt, NLC. UQAM, Montreal, CAND. CSIRO, Victoria, AUSE. Czech Republic, Israel, Greece, Belgium, Slovakia………………..F. Munich-Re, Electricité de France, Elforsk, Hamburg Institute of International Economics,

Uni-Münster, DG-Research, STARDEX, MICE

PRUDENCE objectivesPRUDENCE objectives A series of high resolution climate change scenarios for 2071-2100 for Europe

Characterize level of confidence and variability related to model formulations and climate natural/internal variability

Assess the uncertainty in European regional scenarios resulting from model formulation

Quantitatively assess the risks arising from changes in regional climate over Europe, and estimate changes in extremes like heat waves, flooding and wind storms, by providing a robust estimation of the likelihood and magnitude of the changes

Demonstrate the value of the wide-ranging scenarios by applying them to impacts models focusing on effects on adaptation and mitigation strategies

Assess socio-economic and policy related decisions for which such improved scenarios could be beneficial

Disseminate the results of PRUDENCE widely …

150km globalatmospheric

GCM

12-50km RCMfor relevant region

Coupled GCM (300km atmosphere)

A modelling system for detailed regional scenarios –

the PRUDENCE method

Observed SST/sea-ice

SST/sea-ice change from coupled GCM

Quasi-ensemble probabilitiesQuasi-ensemble probabilities

Precipitation change – Precipitation change – sources of uncertaintysources of uncertainty

95%-confidence: internal variability

C. Frei, ETH

OBS: Slightly different values since the changes in precipitation have been scaled to a 3 K change of the global mean temperature

Precipitation change – Precipitation change – sources of uncertaintysources of uncertainty

95%-confidence: GCM formulation, RCM formulation, internal variability

Probabilistic precipitation Probabilistic precipitation changechange

Sensitivity x signal

Variability sources in sub-areasVariability sources in sub-areas

3 France

1 British Isles

2 Iberian peninsula

4 Central Europe

5 Scandinavia

6 Alps

7 Mediterranean

8 Eastern Europe

M. Déqué, Météo-France

Temperature change – Temperature change – sources of uncertaintysources of uncertainty

DJF

1 2 3 4 5 6 7 8

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Depends on driving model

Also on RCM and scenario

Precipitation change – Precipitation change – sources of uncertaintysources of uncertainty

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Driving GCM and RCM

RCM quite important

Baltic water balanceBaltic water balance

9 RCMs (2 GCMs) 9 RCMs (2 GCMs) ~~50 km 50 km - 2 RCMs - 2 RCMs ~~25 km A225 km A2

-- 3 RCMs 3 RCMs ~~50 km50 km B2B2

PRUDENCE work on extremesPRUDENCE work on extremes

Better understanding of how European weather and climate extremes are likely to change:

Heat waves

Precipitation – heavy and low

Wind storms and storm surges

Precipitation extremesPrecipitation extremes

Changes in HIRHAM 5-year return levelsChanges in HIRHAM 5-year return levels5-day Winter precipitation Summer 1-day precipitation

Increases over Europe except for decreases in south in summer

HIRHAM

Christensen & Christensen, Nature (2003)

Sensitivity due to GCM and RCM resolutionSensitivity due to GCM and RCM resolution

ECHAM HC 50km HC 25km

JAS precipitation [mm/day] JAS precipitation [mm/day] Resolution 50kmResolution 50km

90% wd 95% wd

99% wd 99.9% wd

90% wd 95% wd

99% wd 99.9% wd

JAS precipitation [mm/day] JAS precipitation [mm/day] Resolution 25kmResolution 25km

90% wd 95% wd

99% wd 99.9% wd

JAS precipitation [mm/day] JAS precipitation [mm/day] Resolution 12kmResolution 12km

Wind extremesWind extremes

% change in 90% change in 90thth percentile of 10-metre wind speed percentile of 10-metre wind speed

Increased wind speed intensity in core of Europe north of Alps

RCAO

A2 changes in max winter surge heightsA2 changes in max winter surge heights

HIRHAM

Largest change of 0.3 metres on coasts near German bightChanges (meters) in max surge heights from HadAM3H / HIRHAM.

ConclusionsConclusionsWarming of near-surface temperatures•DJF: west/east gradient with strongest warming in the east•JJA: north/south gradient with strongest warming in the south

Changes in precipitation•DJF: mainly due to driving GCM but also due to RCM•JJA: dryer conditions in all but northern Europe

Large ensemble of simulations allows for the generation of probabilistic regional climate scenarios

Uncertainty of temperature changes•DJF: mainly due to driving GCM•JJA: also due to RCM and scenario

Uncertainty of changes in precipitation•DJF: mainly due to driving GCM but also due to RCM•JJA: to a large extent due to RCM

ConclusionsConclusions•Significant changes of the discharge into the Baltic

•Increased magnitude due to enhanced winter precipitation

•Earlier peak due to earlier snow melt

ConclusionsConclusions

• Heat waves – increased frequency, intensity, and duration of summer heat waves

• Increase in interannual variability of temperature –Summer 2003 could become more likely

• Heavy precipitation – general increase except over S. Europe in summer. Central Europe will have less rainy days, but probably larger intensities

• Wind storms –increased intensity and frequency of high wind speed events in winter

• Storm surges –increase in maximum storm surge level of up to 0.3 metres especially near the German Bight.

Near-surface temperature Near-surface temperature change - DJFchange - DJF

Near-surface temperature Near-surface temperature change - JJAchange - JJA