Southern Annular Mode 1000 Year Reconstruction Abram, N.J.; Mulvaney, R.; Vimeux, F.; Phipps, S.J.; Turner, J.; England, M.H. Abram, N.J. Mulvaney, R. Vimeux, F. Phipps, S.J. Turner, J. England, M.H. Atmospheric and Oceanic Circulation Patterns Reconstruction Southern Annular Mode (SAM) earth science/paleoclimate/climate reconstructions (Southern Annular Mode,null,verification reduction of error,dimensionless,annual,climate reconstructions,null,null,N,95% red noise threshold for reduction of error statistic) earth science/paleoclimate/climate reconstructions (Southern Annular Mode,multiple proxies,95% confidence interval lower bound,dimensionless,annual,climate reconstructions,normalized|smoothed,composite plus scale,N,relative to 1961-1990AD; 70y loess filter of annual data; weighted composite-plus-scale (CPS) with nesting) earth science/paleoclimate/climate reconstructions (Southern Annular Mode,multiple proxies,95% confidence interval margin of error,dimensionless,annual,climate reconstructions,normalized,composite plus scale,N,1.96*rmse; based on standard deviation of the residuals between the SAM reconstruction and the Marshall-SAM Index during the 1957-1995 calibration interval) earth science/paleoclimate/climate reconstructions (Southern Annular Mode,null,verification reduction of error,dimensionless,annual,climate reconstructions,null,null,N,null) earth science/paleoclimate/climate reconstructions (Southern Annular Mode,multiple proxies,null,dimensionless,annual,climate reconstructions,normalized,composite plus scale,N,relative to 1961-1990AD; weighted composite-plus-scale (CPS) with nesting) earth science/paleoclimate/climate reconstructions (Southern Annular Mode,multiple proxies,95% confidence interval upper bound,dimensionless,annual,climate reconstructions,normalized|smoothed,composite plus scale,N,relative to 1961-1990AD; 70y loess filter of annual data; weighted composite-plus-scale (CPS) with nesting) earth science/paleoclimate/instrumental (Southern Annular Mode,null,null,dimensionless,annual,instrumental,normalized,null,N,Marshall SAM index; http://www.antarctica.ac.uk/met/gjma/sam.html; relative to 1961-1990 AD) earth science/paleoclimate/climate reconstructions (age,null,null,year Common Era,null,climate reconstructions,null,null,N,null) earth science/paleoclimate/climate reconstructions (Southern Annular Mode,multiple proxies,null,dimensionless,annual,climate reconstructions,normalized|smoothed,composite plus scale,N,relative to 1961-1990AD; 70y loess filter of annual data; weighted composite-plus-scale (CPS) with nesting) earth science/paleoclimate/reconstructions (Southern Hemisphere Extratropics>LATITUDE >LONGITUDE ) The Southern Annular Mode (SAM) is the primary pattern of climate variability in the Southern Hemisphere, influencing latitudinal rainfall distribution and temperatures from the subtropics to Antarctica. The positive summer trend in the SAM over recent decades is widely attributed to stratospheric ozone depletion; however, the brevity of observational records from Antarctica - one of the core zones that defines SAM variability - limits our understanding of long-term SAM behaviour. Here we reconstruct annual mean changes in the SAM since AD 1000 using, for the first time, proxy records that encompass the full mid-latitude to polar domain across the Drake Passage sector. We find that the SAM has undergone a progressive shift towards its positive phase since the fifteenth century, causing cooling of the main Antarctic continent at the same time that the Antarctic Peninsula has warmed. The positive trend in the SAM since ~AD 1940 is reproduced by multimodel climate simulations forced with rising greenhouse gas levels and later ozone depletion, and the long-term average SAM index is now at its highest level for at least the past 1,000 years. Reconstructed SAM trends before the twentieth century are more prominent than those in radiative-forcing climate experiments and may be associated with a teleconnected response to tropical Pacific climate. Our findings imply that predictions of further greenhouse-driven increases in the SAM over the coming century also need to account for the possibility of opposing effects from tropical Pacific climate changes. STUDY NOTES: 1000 year multiproxy reconstruction of the Southern Annular Mode (SAM) Index. Primary data sources: James Ross Island ice core 1000 year Deuterium and Melt data; PAGES 2k South America data compilation; PAGES 2k Antarctica data compilation. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Abram, N.J. Investigator : Mulvaney, R. Investigator : Vimeux, F. Investigator : Phipps, S.J. Investigator : Turner, J. Investigator : England, M.H. 2014-05-11 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/16197 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/abram2014/abram2014sam.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/abram2014/abram2014sam.txt English https://www.ncdc.noaa.gov/paleo/study/16197 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/abram2014/abram2014sam.txt Nerilie J. Abram, Robert Mulvaney, Françoise Vimeux, Steven J. Phipps, John Turner and Matthew H. England2014Evolution of the Southern Annular Mode during the past millenniumNature Climate Change10.1038/nclimate2235http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2235.html START YEAR: 1000 AD * END YEAR: 2007 AD 180 -90 -180 -30