1200 Year Atlantic Multidecadal Variability and Atlantic Multidecadal Oscillation Reconstructions Wang, J.L.; Yang, B.; Ljungqvist, F.C.; Luterbacher, J.; Osborn, T.J.; Briffa, K.R.; Zorita, E. Wang, J.L. Yang, B. Ljungqvist, F.C. Luterbacher, J. Osborn, T.J. Briffa, K.R. Zorita, E. Atmospheric and Oceanic Circulation Patterns Reconstruction earth science/paleoclimate/climate reconstructions (Atlantic Multidecadal Oscillation Index,multiple proxies,null,degree Celsius,May-Sep,climate reconstructions,anomalized|filtered,principal component analysis|regression analysis,N,w.r.t 1856-1967; 30-year low-pass filter) earth science/paleoclimate/climate reconstructions (Atlantic Multidecadal Variability Index,multiple proxies,null,degree Celsius,May-Sep,climate reconstructions,anomalized,principal component analysis|regression analysis,N,w.r.t 1856-1967) earth science/paleoclimate/climate reconstructions (Atlantic Multidecadal Variability Index,multiple proxies,one root mean square error lower bound,degree Celsius,May-Sep,climate reconstructions,anomalized,principal component analysis|regression analysis,N,w.r.t 1856-1967) earth science/paleoclimate/climate reconstructions (Atlantic Multidecadal Variability Index,multiple proxies,null,degree Celsius,May-Sep,climate reconstructions,anomalized|filtered,principal component analysis|regression analysis,N,w.r.t 1856-1967; 30-year low-pass filter) earth science/paleoclimate/climate reconstructions (age,null,null,year Common Era,null,climate reconstructions,null,null,N,null) earth science/paleoclimate/climate reconstructions (Atlantic Multidecadal Variability Index,multiple proxies,one root mean square error upper bound,degree Celsius,May-Sep,climate reconstructions,anomalized,principal component analysis|regression analysis,N,w.r.t 1856-1967) earth science/paleoclimate/reconstructions earth science/paleoclimate/reconstructions (North Atlantic Ocean>LATITUDE >LONGITUDE ) The North Atlantic experiences climate variability on multidecadal scales, which is sometimes referred to as Atlantic multidecadal variability. However, the relative contributions of external forcing such as changes in solar irradiance or volcanic activity and internal dynamics to these variations are unclear. Here we provide evidence for persistent summer Atlantic multidecadal variability from AD 800 to 2010 using a network of annually resolved terrestrial proxy records from the circum-North Atlantic region. We find that large volcanic eruptions and solar irradiance minima induce cool phases of Atlantic multidecadal variability and collectively explain about 30% of the variance in the reconstruction on timescales greater than 30 years. We are then able to isolate the internally generated component of Atlantic multidecadal variability, which we define as the Atlantic multidecadal oscillation. We find that the Atlantic multidecadal oscillation is the largest contributor to Atlantic multidecadal variability over the past 1,200 years. We also identify coherence between the Atlantic multidecadal oscillation and Northern Hemisphere temperature variations, leading us to conclude that the apparent link between Atlantic multidecadal variability and regional to hemispheric climate does not arise solely from a common response to external drivers, and may instead reflect dynamic processes. STUDY NOTES: Summer (May-September) Atlantic Multidecadal Variability (AMV) was reconstructed by applying the principal component regression method to 46 annually-resolved terrestrial proxy records from the circum-North Atlantic region.The internal variability component of Atlantic Multidecadal Variability (i.e., Atlantic Multidecadal Oscillation; AMO) was estimated by empirically removing externally-forced variations at multidecadal (> 30 years) timescales. Data are reported as sea surface temperature anomalies with respect to AD 1856-1973. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Wang, J.L. Investigator : Yang, B. Investigator : Ljungqvist, F.C. Investigator : Luterbacher, J. Investigator : Osborn, T.J. Investigator : Briffa, K.R. Investigator : Zorita, E. 2017-05-29 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/22031 https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/wang2017/wang2017amv-amo.txt https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/wang2017/wang2017amv-amo.txt English https://www.ncdc.noaa.gov/paleo/study/22031 https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/wang2017/wang2017amv-amo.txt Jianglin Wang, Bao Yang, Fredrik Charpentier Ljungqvist, Jürg Luterbacher, Timothy J. Osborn, Keith R. Briffa, Eduardo Zorita2017Internal and external forcing of multidecadal Atlantic climate variability over the past 1,200 yearsNature Geoscience10.1038/ngeo2962https://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo2962.html START YEAR: 800 AD * END YEAR: 2010 AD -80 0 0 70