noaa-cave-27150 Northern Morocco Holocene Speleothem d18O Data and Rainfall Index Ait Brahim, Y.; Wassenburg, J.A.; Sha, L.; Cruz, F.W.; Deininger, M.; Sifeddine, A.; Bouchaou, L.; Spötl, C.; Edwards, R.L.; Cheng, H. Northern Morocco Holocene Speleothem d18O Data and Rainfall Index 2019-07-04 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/27150 Investigator Y. Ait Brahim Investigator J.A. Wassenburg Investigator L. Sha Investigator F.W. Cruz Investigator M. Deininger Investigator A. Sifeddine Investigator L. Bouchaou Investigator C. Spötl Investigator R.L. Edwards Investigator H. Cheng earth science paleoclimate reconstructions precipitation earth science paleoclimate speleothems oxygen isotopes geoscientificInformation Precipitation Reconstruction 11787 cal yr BP -58 cal yr BP Complete 33.84 33.95 -4.246 -4.09 1260 1260 Continent Africa Northern Africa Morocco Grotte de Piste>LATITUDE 33.84>LONGITUDE -4.09 Continent Africa Northern Africa Morocco Chaara Cave>LATITUDE 33.95>LONGITUDE -4.246 None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

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Boulder CO 80305-3328 USA online ASCII Y. Ait Brahim, J.A. Wassenburg, L. Sha, F.W. Cruz, M. Deininger, A. Sifeddine, L. Bouchaou, Christoph Spotl, R.L. Edwards, H. Cheng 2019 Geophysical Research Letters 10.1029/2019GL082405 https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL082405 Jasper A. Wassenburg, Stephan Dietrich, Jan Fietzke, Jens Fohlmeister, Klaus Peter Jochum, Denis Scholz, Detlev K. Richter, Abdellah Sabaoui, Christoph Spotl, Gerrit Lohmann, Meinrat O. Andreae, Adrian Immenhauser 2016 Nature Geoscience 10.1038/ngeo2767 http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2767.html

The North Atlantic Oscillation is the dominant atmospheric pressure mode in the North Atlantic region and affects winter temperature and precipitation in the Mediterranean, northwest Europe, Greenland, and Asia. The index that describes the sea-level pressure difference between Iceland and the Azores is correlated with a dipole precipitation pattern over northwest Europe and northwest Africa. How the North Atlantic Oscillation will develop as the Greenland ice sheet melts is unclear. A potential past analogue is the early Holocene, during which melting ice sheets around the North Atlantic freshened surface waters, affecting the strength of the meridional overturning circulation. Here we present a Holocene rainfall record from northwest Africa based on speleothem d18O and compare it against a speleothem-based rainfall record from Europe. The two records are positively correlated during the early Holocene, followed by a shift to an anti-correlation, similar to the modern record, during the mid-Holocene. On the basis of our simulations with an Earth system model, we suggest the shift to the anti-correlation reflects a large-scale atmospheric and oceanic reorganization in response to the demise of the Laurentide ice sheet and a strong reduction of meltwater flux to the North Atlantic, pointing to a potential sensitivity of the North Atlantic Oscillation to the melting of ice sheets. STUDY NOTES: Speleothem oxygen isotope (d18O) data and derived rainfall index for 3 speleothems from Northern Morrocco over the Holocene.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/africa/grottedepiste2019d18o.txt NOAA Template File; Grotte de Piste Speleothem GP2 d18O Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/africa/chaara2019cha2d18o.txt NOAA Template File; Chaara Cave Speleothem CHA2 d18O Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/africa/chaara2019rain-index.txt NOAA Template File; Northern Morocco Holocene Rainfall Index GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/africa/chaara2019cha1d18o.txt NOAA Template File; Chaara Cave Speleothem CHA1 d18O Data USA/NOAA DIF Version 9.8.4 2019-07-05 2019-07-05