Niger Delta Mg/Ca Data over the Last 21 Kyr Schmidt, M.W.; Chang, P.; Parker, A.O.; Ji, L.; He, F. Schmidt, M.W. Chang, P. Parker, A.O. Ji, L. He, F. earth science/paleoclimate/paleoceanography (magnesium/calcium,Globorotalia crassaformis,null,millimole per mole,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (number of samples,null,null,count,null,paleoceanography,null,null,N,number of analyses) earth science/paleoclimate/paleoceanography (magnesium/calcium,Globorotalia crassaformis,one standard deviation,millimole per mole,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (Fan 17, Niger Delta>LATITUDE 4.81>LONGITUDE 4.45) Multiple lines of evidence show that cold stadials in the North Atlantic were accompanied by both reductions in Atlantic Meridional Overturning Circulation (AMOC) and collapses of the West African Monsoon (WAM). Although records of terrestrial change identify abrupt WAM variability across the deglaciation, few studies show how ocean temperatures evolved across the deglaciation. To identify the mechanism linking AMOC to the WAM, we generated a new record of subsurface temperature variability over the last 21 kyr based on Mg/Ca ratios in a sub-thermocline dwelling planktonic foraminifera in an Eastern Equatorial Atlantic (EEA) sediment core from the Niger Delta. Our subsurface temperature record shows abrupt subsurface warming during both the Younger Dryas (YD) and Heinrich Event 1. We also conducted a new transient coupled ocean-atmosphere model simulation across the YD that better resolves the western boundary current dynamics and find a strong negative correlation between AMOC strength and EEA subsurface temperatures caused by changes in ocean circulation and rainfall responses that are consistent with the observed WAM change. Our combined proxy and modeling results provide the first evidence that an oceanic teleconnection between AMOC strength and subsurface temperature in the EEA impacted the intensity of the WAM on millennial time scales. STUDY NOTES: Provided Keywords: Deglaciation, abrupt climate change, West African Monsoon, Mg/Ca temperature, subsurface temperature, Niger delta, Younger Dryas, Heinrich Event 1, LGM, GCM modelling, Globorotalia crassaformis NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Schmidt, M.W. Investigator : Chang, P. Investigator : Parker, A.O. Investigator : Ji, L. Investigator : He, F. 2017-11-21 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/23112 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/schmidt2017/schmidt2017-fan17.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/schmidt2017/schmidt2017-fan17.txt English https://www.ncdc.noaa.gov/paleo/study/23112 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/schmidt2017/schmidt2017-fan17.txt Schmidt, Matthew W., Ping Chang, Andrew O. Parker, Link Ji and Feng He2017Deglacial Tropical Atlantic subsurface warming links ocean circulation variability to the West African MonsoonScientific Reports7153901-1110.1038/s41598-017-15637-6 START YEAR: 20910 cal yr BP * END YEAR: 550 cal yr BP 4.45 4.81 4.45 4.81