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, 20-21 October 203, Uppsala
Simulation with ECHO-G (ECHAM4/HOPE-G) - 500 years (Columbus- run), and - 1000 years (Erik run) forced with - variable solar output - volcanic aerosol load - GHG concentrations
Simulated global 1675-1710 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 1550-1800 average; 25-year running averages.
Late Maunder Minimum Cold winters and springs, 1675-1710 Late Maunder Minimum Cold winters and springs, 1675-1710 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). 1675-1710 vs. 1550-1800 Reconstruction from historical evidence, from Luterbacher et al.
1675-1710 vs. 1550-1800 Reconstruction from historical evidence, from Luterbacher et al. Late Maunder Minimum Model-based reconstuction
LMM11671-1684 NAO- and Cooling LMM21685-1708 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.