Comparison of Recent European Climate Trends and Extremes with RegCM3 Future Projections Jeremy Pal Abdus Salam International Centre for Theoretical Physics Trieste, Italy Contributors: Xunqiang Bi, Elfatih Eltahir, Raquel Francisco, Xuejie Gao, Filippo Giorgi
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Comparison of Recent European Climate Trends and Extremes with RegCM3 Future Projections
Comparison of Recent European Climate Trends and Extremes with RegCM3 Future Projections. Jeremy Pal Abdus Salam International Centre for Theoretical Physics Trieste, Italy Contributors: Xunqiang Bi, Elfatih Eltahir, Raquel Francisco, Xuejie Gao, Filippo Giorgi. - PowerPoint PPT Presentation
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Comparison of Recent European Climate Trends
and Extremes with RegCM3 Future Projections
Jeremy Pal
Abdus Salam International Centre for Theoretical PhysicsTrieste, Italy
Premises/Objectives of the studyPremises/Objectives of the studyClimate variability and extremes are of
fundamental importance for an assessment of the impacts of climate change.
Because of their relatively high spatial and temporal resolution Regional Climate Models (RCMs) can be especially useful in the study of climate variability and extremes.
Carry out climate change simulations over the European region for different emission scenarios using an RCM driven by boundary conditions from time-slice GCM simulations
PART I: Regional Climate ModelingBrief Overview
PART II: Reference SimulationMean Climate
PART III: A2 & B2 Scenario SimulationsMeanInterannual VariabilityExtreme Events
PART I:PART I:Regional Climate ModelingRegional Climate Modeling
Brief Overview
GCMGlobal Climate Model (GCM)RCM Nesting
GCM forces RCM at the lateral boundaries and the sea surface.
Added Value of using a Regional Climate Added Value of using a Regional Climate Model for Climate Change Studies.Model for Climate Change Studies.
Increased resolution compared to the driving GCM. Fine scale forcing (e.g. topography, landuse, coastlines,
lakes, aerosol sources). Mesoscale circulations (e.g. North American Monsoon
System). Improved representation of physical processes.
Clouds and precipitation, biosphere, boundary layer, radiation, etc.
Increased confidence for impacts studies. Can include additional processes not present in the
driving GCM. Landuse changes, aerosol effects, lake desiccation, etc.
Summary of RegCM3 CoreSummary of RegCM3 CoreDynamics:
MM5 Hydrostatic (Grell et al 1994)Non-hydrostatic (in the works)
Radiation:CCM3 (Kiehl 1996)
Large-Scale Clouds & Precipitation:SUBEX (Pal et al 2000)
How do recent climatic changes compare to scenarios?
Pal, Giorgi, Bi, GRL 2004
Recent European Extreme SummersRecent European Extreme Summers The western European summer drought of 2003 is
considered one of the severest on record. 20,000 heat related casualties in Western Europe. Worst harvest since World War II.
In contrast, during 2002, many European countries experienced one of their wettest summers on record. Weather systems brought widespread heavy rainfall to central
Europe, causing severe flooding along all the major rivers. The Elbe River reached its highest level in over 500 years of record
Both of these contrasting events resulted in severe damages and losses.
This study addresses whether these seemingly opposites in extremes are consistent the current climate change projections.
Changes in Summer500 hPa Geopotential Heights
( meters) ( meters)
B2-Reference(2071-2100) minus (1961-1990)
NCEP Reanalysis(1976-2000) minus (1951-1975)
Changes in Summer Temperature
B2-Reference(2071-2100) minus (1961-1990)
(C)(C)
CRU Observations(1976-2000) minus (1951-1975)
Changes in Summer Precipitation
B2-Reference(2071-2100) minus (1961-1990)
(% change)(% change)
CRU Observations(1976-2000) minus (1951-1975)
Changes in Summer Temperature:B2-Reference
(C)(C)
Mean Surface(2071-2100) minus (1961-1990)
Interannual Variability(2071-2100) minus (1961-1990)
Changes in Summer Extremes:B2-Reference
(% change)( Days)
Dry Spell Length(2071-2100) minus (1961-1990)
Max 5-Day Precipitation(2071-2100) minus (1961-1990)