CLIMATE MODEL SIMULATES GLOBAL COLD CLIMATE DURING LATE MAUNDER MINIMUM (1675-1710)
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CLIMATE MODEL SIMULATES GLOBAL COLD CLIMATE DURING
LATE MAUNDER MINIMUM (1675-1710)
Hans von Storch, Fidel González-Ruoco, Ulrich Cubasch, Jürg Luterbacher,
Eduardo Zorita, Beate Müller, Stephanie Legutke, and Ulrich Schlese
IUGG Sapporo, JSP 01, 1./2. Juli : The decadal to interdecadal variability of the ocean and atmosphere.
Simulation with ECHO-G (ECHAM4/HOPE-G) for
- 500 years (Columbus-run), and - 1000 years (Erik run)
forced with
- variable solar output- Volcanic aerosol load- GHG concentrations
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: Index, red: 5 year mean, blue:20 year mean
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 Pfister‘s classification.
From Luterbacher, 2001
1675-1710vs. 1550-1800
Reconstruction from historical evidence, from Luterbacher et al.
1675-1710vs. 1550-1800
Reconstruction from historical evidence, from Luterbacher et al.
Late Maunder Minimum
Model-based reconstuction
Simulated global 1675-1710 temperature anomaly
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
10Be measurements
(Crowley, 2000)
Antarctica
North Greenland
Corals off Madagaskar
The empirically reconstructed 338 year record of variations in sea-surface temperatures as inferred from the 1982-95 annual mean 18O -SST calibration equations using SST observations from different sources.
(From Zinke)
Galapagos (E-Pacific, 1oS, 90oW, Dunbar et al., 1994):
367 years of coral 18O records from 1587-1953, with annual resolution. The intervals 1660-80, 1710-1800 and 1870-95 were found warmer than “normal”, whereas the intervals 1600-1660, 1680-1700 (LMM) and 1800-25 cooler than on average. 18O increases of about 0.1-0.15‰ heavier during LMM than between 1660-70 and 1705-50 is indicative for a cooling of 0.5-0.75K.
New Caledonia (SW-Pacific, 22oS, 166oE, Quinn et al., 1998):
335 years of coral 18O records from 1657-1952, with seasonal resolution. The records describe a brief interval of modest cooling in the late 17th century, with an annual mean SST about 0.2-0.3K cooler between 1680-1740 than between 1660-80 and 1740-50
Great Barrier Reef, Abraham Reef (SW-Pacific, 22oS, 153oE, Druffel and Griffin, 1993):
323 years of coral 18O records from 1635-1957, with bi-annual resolution. More positive 18O values (ca. 0.1‰) during the LMM, are consistent with lower SST’s of about 0.5K
Zin
ke, p
ers.
com
mun
icat
ion
deMenocal et al.
(2000)
Simulated differences of ice coverage, in percent, during the LMM event 1675-1710 and the long term mean 1550-1800.
Inst
itu
t fü
r K
üst
enfo
rsch
un
g
I f K
LMM1 1671-1684 NAO- and Cooling
LMM2 1685-1708 NAO+ and Warming
Irene Fischer-Bruns, pers. comm.
Conclusions• AOGCM ECHO-G has been integrated with natural forcing
(estimates) related to solar output and volcanic aerosols and anthropogenic GHG forcing over several hundred years (Columbus: 450 yrs, Erik the Red: 1000 yrs).
• Both simulations generate a globally cooler Northern winter Earth, 1400-1800, consistent with the concept of LIA. The cooling is considerably larger than described by Mann et al. The 100ß yrs Erik-simulation generates a medieval warm time during northern winter.
• Both simulations simulate a marked global (north of 20°S) cooling during the Late Maunder Minimum in Northern winter. (Also: Dalton Minimum). The extra cooling amounts to 0.2-0.5K.
• Model simulations consistent with a number of proxy data, in Europe, and across the globe (corals, ice cores).
• Model simulates a significant ice anomaly in the Labrador Sea and adjacent seas during the LMM. NAO not uniform during LMM.