Titulo

subtituloCLIMATE SIMULATIONS IN THE LATE

QUATERNARY:

E. Zorita

M. Montoya

F. Valero

J. F. González-Rouco

J. P. Montávez

Observations

Scenario projections

Reconstructions

Simulation of past scenarios

Understand the past … to project the future

GCM: ECHO-gEMIC: Climber-3αRCM: MM5

Ocean component(DKRZ Rep. 13, 1997)

•Prim. Eq. & Thermodyn.+ sea ice model with snow cover

•Gauss. T42 ~ 2.8 x 2.8 ºlat x ºlon 0.5 ºlat x ºlon Equator

•20 levels

Atmospheric component(MPI Rep. 218, 1996)

•ECMWFMPI•~ECHAM3

+ fresh water on glaciers+ river runnoff + partial ice cover

•T30 ~ 3.75 x 3.75 ºlat x ºlon•19 vertical levels:

Highest: 10 hPa~ 30 kmLowest:~ 30 m

ECHO-g simulations ECHO-g simulations

Climate since 1000 AD

ECHO-g simulations ECHO-g simulations

Climate since 1000 AD

Zorita et al., GRL, 2005

González-Rouco et al., ESA, 535, 329-338, 2003

Testing climate reconstructions: GCMS as a surrogate realityTesting climate reconstructions: GCMS as a surrogate reality

Storch et al. Science, 306, 679-682, 2004

Zorita & González-Rouco, GRL, 29, 14, 2002

Zorita et al. J. Climate, 16, 1378, 2003

González-Rouco et al., GRL, 30, 216, 2003

Climate since 1000 AD

1675-1710vs. 1550-1800

Reconstruction from historical evidence, from Luterbacher et al.

Late Maunder Minimum

Model-based simulation

Simulations & reconstructions:Simulations & reconstructions:

Regional viewRegional view

Zorita et al. Met. Schr. 13,4, 271-289, 2004

Climate since 1000 AD

RCM simulations with MM5RCM simulations with MM5 1550-1990 AD1550-1990 AD

●Two way nesting● D1 135 D2 45km●27 sigma levels (Ptop 100mb)●Nudging●Forcing from ECHO-g 1000 yr ●Period 1500-1990●Output every 6 hours

Climate since 1000 AD

Late Maunder Minimum

1675-1710 vs. 1550-1800

RCM simulations with MM5RCM simulations with MM5 1550-1990 AD1550-1990 AD

Summer

Winter

Climate since 1000 AD

Late Maunder Minimum

1675-1710 vs. 1550-1800

Sensitivity to model employedClimer-3Climer-3αα experiments experiments

GCMs of different complexity

Climber-3Climer-3Climer-3αα experiments experiments

GCMs of different complexity Montoya et al., Clim. Dyn., 2005

Bauer et al., Paleoceanogr.., 2004

Petoukhov et al., Clim. Dyn.., 2005a

Petoukhov et al., Clim. Dyn.., 2005b

Dansgaard-Oeschger and Heinrich events (GRIP)

(oC)

Holocene last ice age

Climer-3Climer-3αα experiments experiments

GCMs of different complexity

•Understanding of the past and reliable prediction of the future requires reconstruction and simulation approaches.

•GCMs simulate plausible climate states compatible with external forcing.

• Paleo simulations as a framework to study mechanisms which led to relevant climate changes in the past.

• GCMs used in IPCC scenario simulations should come to ‘agreement’ with reconstructions of past climate.

• Climate simulations as a virtual reality to test methods & hypothesis used in climate reconstructions.

• RCMs enhance our knowledge of variability at regional and local scales.

• GCMs of different complexity: Suggesting proccesses and mech., quantify importance Simulation of holocene LGM, abrupt climate change, Climer-3Climer-3αα

Context / Outlook