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Titulo. CLIMATE SIMULATIONS IN THE LATE QUATERNARY:. subtitulo. E. Zorita. J. P. Montávez. M. Montoya F. Valero J. F. González-Rouco. Understand the past … to project the future. GCM: ECHO-g EMIC: Climber-3 α RCM: MM5. Observations. Reconstructions. Scenario projections.
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Titulo CLIMATE SIMULATIONS IN THE LATE QUATERNARY: subtitulo E. Zorita J. P. Montávez M. Montoya F. Valero J. F. González-Rouco
Understand the past … to project the future GCM: ECHO-gEMIC: Climber-3αRCM: MM5 Observations Reconstructions Scenario projections Simulation of past scenarios
Climate since 1000 AD • 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 km • Lowest:~ 30 m ECHO-g simulations • 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
Climate since 1000 AD ECHO-g simulations Zorita et al., GRL, 2005 González-Rouco et al., ESA, 535, 329-338, 2003
Climate since 1000 AD Testing climate reconstructions: GCMS as a surrogate reality Storch et al. Science, 306, 679-682, 2004 González-Rouco et al., GRL, 30, 216, 2003 Zorita et al. J. Climate, 16, 1378, 2003 Zorita & González-Rouco, GRL, 29, 14, 2002
Reconstruction from historical evidence, from Luterbacher et al. Climate since 1000 AD Simulations & reconstructions: Regional view Late Maunder Minimum Model-based simulation Zorita et al. Met. Schr. 13,4, 271-289, 2004 1675-1710vs. 1550-1800
Climate since 1000 AD RCM simulations with MM5 1550-1990 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 Late Maunder Minimum 1675-1710 vs. 1550-1800
Climate since 1000 AD Winter RCM simulations with MM5 1550-1990 AD Summer Late Maunder Minimum 1675-1710 vs. 1550-1800
GCMs of different complexity Sensitivity to model employed Climer-3α experiments
GCMs of different complexity Montoya et al., Clim. Dyn., 2005 Climber-3a Climer-3α experiments Bauer et al., Paleoceanogr.., 2004 Petoukhov et al., Clim. Dyn.., 2005a Petoukhov et al., Clim. Dyn.., 2005b
GCMs of different complexity Dansgaard-Oeschger and Heinrich events (GRIP) Climer-3α experiments last ice age Holocene (oC)
Context / Outlook • 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-3α