Moroccan speleothem and treering records suggest a variable positive state of the North Atlantic Oscillation during the Medieval Warm Period Wassenburg, J.A.; Immenhauser, A.; Richter, D.K.; Niedermayr, A.; Riechelmann, S.; Fietzke, J.; Scholz, D.; Jochum, K.P.; Fohlmeister, J.; Schröder-Ritzrau, A.; Sabaoui, A.; Riechelmann, D.F.C.; Schneider, L.; Esper, J. Wassenburg, J.A. Immenhauser, A. Richter, D.K. Niedermayr, A. Riechelmann, S. Fietzke, J. Scholz, D. Jochum, K.P. Fohlmeister, J. Schröder-Ritzrau, A. Sabaoui, A. Riechelmann, D.F.C. Schneider, L. Esper, J. Medieval Climate Anomaly (MCA) North Atlantic Oscillation Palmer Drought Index Reconstruction drought hydrology precipitation earth science/paleoclimate/climate reconstructions|tree ring (age,null,null,year Common Era,null,climate reconstructions|tree ring,null,null,N,null) earth science/paleoclimate/climate reconstructions|tree ring (Palmer Drought Severity Index,ring width,null,dimensionless,null,climate reconstructions|tree ring,null,null,N,null) earth science/paleoclimate/speleothems (magnesium,aragonite,null,parts per million,null,speleothems,raw,inductively-coupled plasma mass spectrometry|laser ablation,N,null) earth science/paleoclimate/speleothems (age,null,null,year Common Era,null,speleothems,null,null,N,null) earth science/paleoclimate/speleothems (strontium,aragonite,null,parts per million,null,speleothems,raw,inductively-coupled plasma mass spectrometry|laser ablation,N,null) earth science/paleoclimate/speleothems earth science/paleoclimate/speleothems (Grotte de Piste>LATITUDE 33.84>LONGITUDE -4.09) (Atlas Mountains IS>LATITUDE 33.4>LONGITUDE -5.1667) We present a magnesium (Mg) and strontium (Sr) record from an aragonitic speleothem(Grotte de Piste, Morocco, 34‬ºN; 04ºW) providing a reconstruction of effective rainfall from 619-1962 AD. The corresponding drip site was monitored over two years for drip water Mg/Ca and Sr/Ca ratios. Results show evidence for prior aragonite precipitation, which can explain negative correlations between speleothem Mg and Sr concentrations. The data shown here have important climate implications concerning the evolution of the North Atlantic Oscillation (NAO). A comparison of the stalagmite data from Grotte de Piste with an updated tree ring based drought reconstruction from Morocco and other NAO related proxy records confirms that the medieval warm period (MWP) was dominated by NAO+ conditions. The stalagmite record and multiple proxy records from the Iberian Peninsula, however, suggest that considerable rainfall variability occurred during the MWP. This implies that the NAO has been more variable during the MWP than formerly suggested. STUDY NOTES: Keywords: trace metals, drought, hydrology, precipitation, North Atlantic Oscillation, Medieval Climate Anomaly, speleothem, prior calcite precipitation, aragonite, trace elements. scPDSI reconstruction added 5/2/2014 NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Wassenburg, J.A. Investigator : Immenhauser, A. Investigator : Richter, D.K. Investigator : Niedermayr, A. Investigator : Riechelmann, S. Investigator : Fietzke, J. Investigator : Scholz, D. Investigator : Jochum, K.P. Investigator : Fohlmeister, J. Investigator : Schröder-Ritzrau, A. Investigator : Sabaoui, A. Investigator : Riechelmann, D.F.C. Investigator : Schneider, L. Investigator : Esper, J. 2013-11-27 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/15894 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/africa/wassenburg2013-mg-sr.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/africa/wassenburg2013pdsi.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/africa/wassenburg2013-mg-sr.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/africa/wassenburg2013pdsi.txt English https://www.ncdc.noaa.gov/paleo/study/15894 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/africa/wassenburg2013-mg-sr.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/africa/wassenburg2013pdsi.txt J.A. Wassenburg, A. Immenhauser,D. K. Richter, A. Niedermayr, S. Riechelmann, J. Fietzke, D. Scholz, K. P. Jochum, J. Fohlmeister, A. Schröder-Ritzrau, A.Sabaoui,D.F.C. Riechelmann,L.Schneider,J.Esper2013Moroccan speleothem and treering records suggest a variable positive state of the North Atlantic Oscillation during the Medieval Warm PeriodEarth and Planetary Science Letters375291-302http://www.blogs.uni-mainz.de/fb09climatology/files/2012/03/Wassenburg_2013_EPSL.pdf Jan Esper, David Frank, Ulf Büntgen, Anne Verstege, Jürg Luterbacher, and Elena Xoplaki2007Long-term drought severity variations in MoroccoGeophysical Research Letters34L1770210.1029/2007GL030844http://onlinelibrary.wiley.com/doi/10.1029/2007GL030844/abstract START YEAR: 748 AD * END YEAR: 2008 AD -5.1667 33.4 -4.09 33.84