TY - JOUR
T1 - Rainfall variations in central Indo-Pacific over the past 2,700 y
AU - Tan, Liangcheng
AU - Shen, Chuan Chou
AU - Löwemark, Ludvig
AU - Chawchai, Sakonvan
AU - Lawrence Edwards, R.
AU - Cai, Yanjun
AU - Breitenbach, Sebastian F.M.
AU - Cheng, Hai
AU - Chou, Yu Chen
AU - Duerrast, Helmut
AU - Partin, Judson W.
AU - Cai, Wenju
AU - Chabangborn, Akkaneewut
AU - Gao, Yongli
AU - Kwiecien, Ola
AU - Wu, Chung Che
AU - Shi, Zhengguo
AU - Hsu, Huang Hsiung
AU - Wohlfarth, Barbara
N1 - Publisher Copyright:
© 2019 National Academy of Sciences. All rights reserved.
PY - 2019/8/27
Y1 - 2019/8/27
N2 - Tropical rainfall variability is closely linked to meridional shifts of the Intertropical Convergence Zone (ITCZ) and zonal movements of the Walker circulation. The characteristics and mechanisms of tropical rainfall variations on centennial to decadal scales are, however, still unclear. Here, we reconstruct a replicated stalagmite-based 2,700-y-long, continuous record of rainfall for the deeply convective northern central Indo-Pacific (NCIP) region. Our record reveals decreasing rainfall in the NCIP over the past 2,700 y, similar to other records from the northern tropics. Notable centennial- to decadal-scale dry climate episodes occurred in both the NCIP and the southern central Indo-Pacific (SCIP) during the 20th century [Current Warm Period (CWP)] and the Medieval Warm Period (MWP), resembling enhanced El Niño-like conditions. Further, we developed a 2,000-y-long ITCZ shift index record that supports an overall southward ITCZ shift in the central Indo-Pacific and indicates southward mean ITCZ positions during the early MWP and the CWP. As a result, the drying trend since the 20th century in the northern tropics is similar to that observed during the past warm period, suggesting that a possible anthropogenic forcing of rainfall remains indistinguishable from natural variability.
AB - Tropical rainfall variability is closely linked to meridional shifts of the Intertropical Convergence Zone (ITCZ) and zonal movements of the Walker circulation. The characteristics and mechanisms of tropical rainfall variations on centennial to decadal scales are, however, still unclear. Here, we reconstruct a replicated stalagmite-based 2,700-y-long, continuous record of rainfall for the deeply convective northern central Indo-Pacific (NCIP) region. Our record reveals decreasing rainfall in the NCIP over the past 2,700 y, similar to other records from the northern tropics. Notable centennial- to decadal-scale dry climate episodes occurred in both the NCIP and the southern central Indo-Pacific (SCIP) during the 20th century [Current Warm Period (CWP)] and the Medieval Warm Period (MWP), resembling enhanced El Niño-like conditions. Further, we developed a 2,000-y-long ITCZ shift index record that supports an overall southward ITCZ shift in the central Indo-Pacific and indicates southward mean ITCZ positions during the early MWP and the CWP. As a result, the drying trend since the 20th century in the northern tropics is similar to that observed during the past warm period, suggesting that a possible anthropogenic forcing of rainfall remains indistinguishable from natural variability.
KW - Central Indo-Pacific
KW - ENSO
KW - ITCZ
KW - Rainfall
KW - Stalagmite
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U2 - 10.1073/pnas.1903167116
DO - 10.1073/pnas.1903167116
M3 - Article
C2 - 31405969
AN - SCOPUS:85071397754
SN - 0027-8424
VL - 116
SP - 17201
EP - 17206
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 35
ER -