North Icelandic Shelf 1350 Year Molusc Radiocarbon Data Wanamaker, A.D.; Butler, P.G.; Scourse, J.D.; Heinemeier, J.; Eiríksson, J.; Knudsen, K.L.; Richardson, C.A. Wanamaker, A.D. Butler, P.G. Scourse, J.D. Heinemeier, J. Eiríksson, J. Knudsen, K.L. Richardson, C.A. Little Ice Age (LIA) Medieval Climate Anomaly (MCA) Meridional Overturning Circulation (MOC) earth science/paleoclimate/paleoceanography (delta 13C,bivalve,null,per mil VPDB,null,paleoceanography,null,null,N,Arctica islandica) earth science/paleoclimate/paleoceanography (age,null,null,calendar year before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 18O,bivalve,null,per mil VPDB,null,paleoceanography,null,null,N,Arctica islandica) earth science/paleoclimate/paleoceanography (age,null,null,year Common Era,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (Trawl B05AD03>LATITUDE 66.5265>LONGITUDE -18.1957) Despite numerous investigations, the dynamical origins of the Medieval Climate Anomaly and the Little Ice Age remain uncertain. A major unresolved issue relating to internal climate dynamics is the mode and tempo of Atlantic meridional overturning circulation variability, and the significance of decadal-to-centennial scale changes in Atlantic meridional overturning circulation strength in regulating the climate of the last millennium. Here we use the time-constrained high-resolution local radiocarbon reservoir age offset derived from an absolutely dated annually resolved shell chronology spanning the past 1,350 years, to reconstruct changes in surface ocean circulation and climate. The water mass tracer data presented here from the North Icelandic shelf, combined with previously published data from the Arctic and subtropical Atlantic, show that surface Atlantic meridional overturning circulation dynamics likely amplified the relatively warm conditions during the Medieval Climate Anomaly and the relatively cool conditions during the Little Ice Age within the North Atlantic sector. STUDY NOTES: Radiocarbon content of shells of the long-lived marine bivalve Arctica islandica collected on the North Icelandic shelf. The shells were absolutely dated using crossdating techniques derived from dendrochronology, and provide a 1350-year record of water mass migration and strength of the Atlantic meridional overturning circulation. Shells were collected near the island of Grimsey, North Icelandic Shelf, at a water depth of 81-83 m from the RV Bjarni Saemundsson (Cruise No. B05-2006, trawl B05AD03). Trawl B05AD03: 66°31.59'N, 18°11.74'W, ~82m water depth. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Wanamaker, A.D. Investigator : Butler, P.G. Investigator : Scourse, J.D. Investigator : Heinemeier, J. Investigator : Eiríksson, J. Investigator : Knudsen, K.L. Investigator : Richardson, C.A. 2012-06-21 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/13034 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wanamaker2012/wanamaker2012.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wanamaker2012/wanamaker2012.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wanamaker2012/wanamaker2012.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wanamaker2012/wanamaker2012.xls English https://www.ncdc.noaa.gov/paleo/study/13034 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wanamaker2012/wanamaker2012.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/wanamaker2012/wanamaker2012.xls Wanamaker, A.D., P.G. Butler, J.D. Scourse, J. Heinemeier, J. Eiríksson, K.L. Knudsen, and C.A. Richardson. 2012. Surface changes in the North Atlantic meridional overturning circulation during the last millennium. Nature Communications, Published 12 Jun 2012. DOI: 10.1038/ncomms1901 START YEAR: 675 AD * END YEAR: 1950 AD -18.1957 66.5265 -18.1957 66.5265