TY - JOUR
T1 - Trends and variability in the Southern Annular Mode over the Common Era
AU - King, Jonathan
AU - Anchukaitis, Kevin J.
AU - Allen, Kathryn
AU - Vance, Tessa
AU - Hessl, Amy
N1 - Funding Information:
The authors thank David Meko for providing the original PDSI estimation code on which ours is based. This research is supported by a grant from the US National Science Foundation’s Paleo Perspectives on Climatic Change program (P2C2) AGS-1803946 to K.J.A. and A.H; an Australian Research Council Special Research Initiative for Antarctic Gateway Partnership (SR140300001) to T.V.; a grant from the Australian Antarctic Program Partnership (ASCI000002) to T.V., and a grant from the Australian Research Council (FT200100102) to K.A. We acknowledge the World Climate Research Programme’s Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modeling groups for producing and making available their model output. We also acknowledge the many proxy paleoclimatologists whose work has contributed to the large-scale networks and databases used in this paper.
Publisher Copyright:
© 2023, The Author(s).
PY - 2023/12
Y1 - 2023/12
N2 - The Southern Annular Mode (SAM) is the leading mode of atmospheric variability in the extratropical Southern Hemisphere and has wide ranging effects on ecosystems and societies. Despite the SAM’s importance, paleoclimate reconstructions disagree on its variability and trends over the Common Era, which may be linked to variability in SAM teleconnections and the influence of specific proxies. Here, we use data assimilation with a multi-model prior to reconstruct the SAM over the last 2000 years using temperature and drought-sensitive climate proxies. Our method does not assume a stationary relationship between the SAM and the proxy records and allows us to identify critical paleoclimate records and quantify reconstruction uncertainty through time. We find no evidence for a forced response in SAM variability prior to the 20th century. We do find the modern positive trend falls outside the 2σ range of the prior 2000 years at multidecadal time scales, supporting the inference that the SAM’s positive trend over the last several decades is a response to anthropogenic climate change.
AB - The Southern Annular Mode (SAM) is the leading mode of atmospheric variability in the extratropical Southern Hemisphere and has wide ranging effects on ecosystems and societies. Despite the SAM’s importance, paleoclimate reconstructions disagree on its variability and trends over the Common Era, which may be linked to variability in SAM teleconnections and the influence of specific proxies. Here, we use data assimilation with a multi-model prior to reconstruct the SAM over the last 2000 years using temperature and drought-sensitive climate proxies. Our method does not assume a stationary relationship between the SAM and the proxy records and allows us to identify critical paleoclimate records and quantify reconstruction uncertainty through time. We find no evidence for a forced response in SAM variability prior to the 20th century. We do find the modern positive trend falls outside the 2σ range of the prior 2000 years at multidecadal time scales, supporting the inference that the SAM’s positive trend over the last several decades is a response to anthropogenic climate change.
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U2 - 10.1038/s41467-023-37643-1
DO - 10.1038/s41467-023-37643-1
M3 - Article
C2 - 37087516
AN - SCOPUS:85153553514
SN - 2041-1723
VL - 14
JO - Nature communications
JF - Nature communications
IS - 1
M1 - 2324
ER -