Evidence for the climate during the Late Maunder Minimum from proxy data available within KIHZ KIHZ Consortium Presented by Hans von Storch KIHZ = Climate in historical times A project of the Helmholtz Gemeinschaft Deutscher Forschungszentren (HGF) With contributions from GKSS, GFZ, AWI, FZJ, GEOMAR, U Mainz, U Madrid AGU 2002 Spring Meeting, Washington Convention Center, Washington, DC, May 2002

Motivation Empirical knowledge about the Late Maunder Minimum (LMM), The different groups within the KIHZ project were asked to come up with their best guesses concerning the state during the LMM period, relative to a normal , and its uncertainty both in the physical interpretation and the dating. The results are compared with an extended forced simulation with the solar/volcanic aerosol model simulation (see talk by Cubasch).

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. From Luterbacher, vs Reconstruction from historical evidence, from Luterbacher et al.

Baltic Sea ice winter index after Koslowski (1998) grey: Index, red: 5 year mean, blue:20 year mean

Global map of the main regions with annually resolving proxy data for pre-1750 temperatures. From Jones et al., 2001.

variations in mean annual coral d 18 O annual coral growth rate Corals Off Madagaskar

The empirically reconstructed 338 year record of variations in sea-surface temperatures as inferred from the annual mean d 18 O -SST calibration equations using SST observations from different sources. (From Zinke)

Marine Sediments Off Peru Indicator for bio-productivity and intensity of upwelling in the ocean off Peru. The indicator is derived from characteristics in the marine sediment. Higher values are associated with stronger upwelling and lower values with reduced upwelling. deMenocal et al. (2000)

Lake Sediments From Lake Holzmaar magnetic susceptibility = clastic input? 13 C + Aulacoseira subarctica Reduced growing season? Dryer winters?

Ice Cores From Greenland and Antarctica Stacked isotope record from five North-Greenland ice cores (Schwager, 2000) Stacked isotope record from three ice cores from Dronning Maud Land, Antarctica (Graf et al., in press ) Reconstruction of solar variability, deduced from 10 Be measurements (Crowley, 2000) Antarctica North Greenland

New Mexico. Low values indicate dryness. Error < 50 years. From Polyak and Asmerom (2001) NW Scotland: Normalized annual bandwidth. Error < 20 years. From Proctor et al. (2000). Speleothems

Simulated air temperature minus (cf. talk given by Cubasch)

A first attempt was made to collect the diverse evidence from a variety of proxy data available from within the project Klima in historischen Zeiten (KIHZ). So far too often, proxy data are extracted and interpreted without consistency check with other proxy-data, both in terms of informational content as well as dating. In the present case, the different groups within KIHZ have tried to overcome these obstacles. As a result, the LMM emerges as a global phenomenon. The consistency with the modeling results, as a response to time dependent solar output, stratospheric aerosol load and greenhouse gas concentrations, suggest that similar dynamics are behind the real and the simulated LMM. However, this suggestion should be considered with caution until further analysis of the model data and comparisons with other proxy-data are completed.

CONTRIBUTORS J. Zinke, Christian Dullo, Anton Eisenhauer - GEOMAR, Kiel H. von Storch, B. Müller, E. Zorita - Institute for Coastal Research, GKSS Research Centre, Geesthacht B. Rein - Institute für Geowissenschaft, Universität Mainz H. B. Mieding, H. Miller - Alfred-Wegener-Institut für Polar- und Meeresforschung, Bremerhaven A. Lücke, G.H. Schleser - Forschungszentrum Jülich M.J Schwab, J.F.W. Negendank, U. Kienel - Geoforschungszentrum Potsdam J.F. González-Ruoco - Departamento de Astrofísica y CC de la Atmósfera. UCM, Madrid

Simulated precipitation minus (cf. talk given by Cubasch)