Presentation on theme: "Simulation of the Late Maunder Minimum with global and regional climate models Hans von Storch, Beate Müller GKSS Research Center MUSCAD workshop, 20-21."— Presentation transcript:
Simulation of the Late Maunder Minimum with global and regional climate models Hans von Storch, Beate Müller GKSS Research Center MUSCAD workshop, October 203, Uppsala
Simulation with ECHO-G (ECHAM4/HOPE-G) years (Columbus- run), and years (Erik run) forced with - variable solar output - volcanic aerosol load - GHG concentrations
Simulated global temperature anomaly deMenocal et al. (2000) Ice conditions off Iceland (Koch, 1945)
Information provided by Fidel González-Rouco and Simon Tett HadCM3 ECHO-G differences relative to the average; 25-year running averages.
Late Maunder Minimum Cold winters and springs, Late Maunder Minimum Cold winters and springs, Analysis of Columbus run, only.
Baltic Sea ice winter index after Koslowski (1998) grey: raw index, red: 5 year mean, blue:20 year mean
Mean winter temperatures in Tallin as reconstructed by Tarand & Nordli, 2001
The Late Maunder Minimum (LMM) is the coldest phase of the so-called Little Ice Age with marked climatic variability over wide parts of Europe. Temperature conditions in Switzerland according to Pfisters classification (1999) vs Reconstruction from historical evidence, from Luterbacher et al.
vs Reconstruction from historical evidence, from Luterbacher et al. Late Maunder Minimum Model-based reconstuction
LMM NAO- and Cooling LMM NAO+ and Warming Irene Fischer-Bruns, pers. comm.
gridding: Spatial: 0.5° x 0.5° Temporal: 6 h REMO Model Area ECHO-G gridding
Regionalized sea ice data Main land use types in Germany from 7th century area [%]
Differences reconstructed data - REMOreconstructed data - ECHO January
Differences reconstructed data - REMOreconstructed data - ECHO July
REMO und Luterbacher Seasonal temperature anomalies in areas with skill of reconstruction > 0.5 Winter Herbst Frühling Sommer
Temperaturanomalie des LMM für Zentral-England Winter
Winterliche Mitteltemperatur und Anomalie des LMM für den Tallinner Hafen Mittel
Conclusions Two multi-century simulations concluded. Natural forcing plus GHGs. Work done by a European consortium. Model simulations are consistent. Tools for dynamical downscaling for the Baltic catchment area developed. Models simulates significant winter cooling during LMM; similar event in HadCM3. Similarity to observed features, but variations much stronger than empirical reconstructions by Mann and others. LMM winter cooling is global event. Cooling in Europe is just a manifestation, and not mainly related to anomalous easterlies in Northern Europe.