# Southern Annular Mode (SAM) Index 1,000 Year Reconstructions #----------------------------------------------------------------------- # World Data Service for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program # National Centers for Environmental Information (NCEI) #----------------------------------------------------------------------- # Template Version 3.0 # Encoding: UTF-8 # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/23130 # Description: NOAA Landing Page # Online_Resource: https://www1.ncdc.noaa.gov/pub/data/paleo/reconstructions/datwyler2017/datwyler2017.txt # Description: NOAA location of the template # # Original_Source_URL: # Description: # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Climate Reconstructions # # Dataset DOI: # # Parameter_Keywords: atmospheric circulation #-------------------- # Contribution_Date # Date: 2017-12-05 #-------------------- # File_Last_Modified_Date # Date: 2017-12-05 #-------------------- # Title # Study_Name: Southern Annular Mode (SAM) Index 1,000 Year Reconstructions #-------------------- # Investigators # Investigators: Dätwyler, C.; Neukom, R.; Abram, N.J.; Gallant, A.J.E.; Grosjean, M.; Jacques-Coper, M.; Karoly, D.J.; Villalba, R. #-------------------- # Description_Notes_and_Keywords # Description: Southern Annular Mode (SAM) index reconstructions and underlying southern hemisphere proxy data for the past 1,000 years. # Data files are as follows: # # Best_SAM_reconstruction.txt # Ensemble median of our "best" SAM index reconstruction (the long calibration DJF Cor & Stat SAM reconstruction) and target Fogt SAM index together with their 30-year loess filtered values. Additionally the full ensemble of reconstructions (1000) is provided (columns "EM1" to "EM1000"). # # Reconstructions_Annual_LC.txt # Ensemble medians of the annual SAM index reconstructions and target Fogt SAM index together with their 30-year loess filtered values. All values are anomalies with respect to the long calibration interval 1905-2005. # # Reconstructions_Annual_SC.txt # Ensemble medians of the annual SAM index reconstructions and target Marshall SAM index together with their 30-year loess filtered values. All values are anomalies with respect to the short calibration interval 1958-1995. # # Reconstructions_DJF_LC.txt # Ensemble medians of the DJF SAM index reconstructions and target Fogt SAM index together with their 30-year loess filtered values. All values are anomalies with respect to the long calibration interval 1905-2005. # # Reconstructions_DJF_SC.txt # Ensemble medians of the DJF SAM index reconstructions and target Marshall SAM index together with their 30-year loess filtered values. All values are anomalies with respect to the short calibration interval 1958-1995. # # Proxyrecords_DJF_AllProxiesRecon_LC.txt # Data of the proxy records used for the DJF All Proxies long calibration reconstruction. # # Proxyrecords_DJF_BestRecon.txt # Data of the proxy records used for our "best" DJF SAM index reconstruction (the long calibration DJF Cor & Stat SAM reconstruction). # # Metadata_DJF_AllProxiesRecon_LC.txt # Meta data of the proxy records in Proxyrecords_DJF_AllProxiesRecon_LC.txt. # # Metadata_DJF_BestRecon.txt # Meta data of the proxy records in Proxyrecords_DJF_BestRecon.txt. # #-------------------- # Publication # Authors: Christoph Dätwyler, Raphael Neukom, Nerilie J. Abram, Ailie J.E. Gallant, Martin Grosjean, Martín Jacques-Coper, David J. Karoly, Ricardo Villalba # Published_Date_or_Year: 2017-12-05 # Published_Title: Teleconnection stationarity, variability and trends of the Southern Annular Mode (SAM) during the last millennium # Journal_Name: Climate Dynamics # Volume: # Edition: # Issue: # Pages: # Report_Number: # DOI: 10.1007/s00382-017-4015-0 # Online_Resource: https://link.springer.com/article/10.1007%2Fs00382-017-4015-0 # Full_Citation: # Abstract: The Southern Annular Mode (SAM) is the leading mode of atmospheric interannual variability in the Southern Hemisphere (SH) extra-tropics. Here, we assess the stationarity of SAM spatial correlations with instrumental and paleoclimate proxy data for the past millennium. The instrumental period shows that temporal non-stationarities in SAM teleconnections are not consistent across the SH land areas. This suggests that the influence of the SAM index is modulated by regional effects. However, within key-regions with good proxy data coverage (South America, Tasmania, New Zealand), teleconnections are mostly stationary over the instrumental period. Using different stationarity criteria for proxy record selection, we provide new austral summer and annual mean SAM index reconstructions over the last millennium. Our summer SAM reconstructions are very robust to changes in proxy record selection and the selection of the calibration period, particularly on the multi-decadal timescale. In contrast, the weaker performance and lower agreement in the annual mean SAM reconstructions point towards changing teleconnection patterns that may be particularly important outside the summer months. Our results clearly portend that the temporal stationarity of the proxy-climate relationships should be taken into account in the design of comprehensive regional and hemispherical climate reconstructions. The summer SAM reconstructions show no significant relationship to solar, greenhouse gas and volcanic forcing, with the exception of an extremely strong negative anomaly following the AD 1257 Samalas eruption. Furthermore, reconstructed pre-industrial summer SAM trends are very similar to trends obtained by model control simulations. We find that recent trends in the summer SAM lie outside the 5-95% range of pre-industrial natural variability. #------------------ # Funding_Agency # Funding_Agency_Name: Swiss National Science Foundation # Grant: Ambizione PZ00P2_154802 #------------------ # Funding_Agency # Funding_Agency_Name: Australian Research Council # Grant: Centre of Excellence for Climate System Science CE110001028 #------------------ # Funding_Agency # Funding_Agency_Name: CONICYT-Chile # Grant: PAI79160105, FONDAP15110009 #------------------ # Site_Information # Site_Name: Southern Hemisphere extra-tropics # Location: Geographic Region>Southern Hemisphere # Country: # Northernmost_Latitude: -30 # Southernmost_Latitude: -90 # Easternmost_Longitude: 180 # Westernmost_Longitude: -180 # Elevation: #------------------ # Data_Collection # Collection_Name: Datwyler2017SAM # Earliest_Year: 1000 # Most_Recent_Year: 2005 # Time_Unit: CE # Core_Length: # Notes: #------------------ # Chronology_Information # Chronology: # #----------------