FN Archimer Export Format
PT J
TI Millennial variability in intermediate ocean circulation and Indian monsoonal weathering inputs during the last deglaciation and Holocene
BT 
AF Yu, Zhaojie
   Colin, Christophe
   Wilson, David J.
   Bayon, Germain
   Song, Zehua
   Sepulcre, Sophie
   Dapoigny, Arnaud
   Li, Yuanlong
   Wan, Shiming
AS 1:1,2,3;2:4;3:5;4:6;5:1;6:4;7:7;8:8;9:1,2,3;
FF 1:;2:;3:;4:PDG-REM-GEOOCEAN-ASTRE;5:;6:;7:;8:;9:;
C1 Key Laboratory of Marine Geology and Environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 ,China
   Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and Technology Qingdao 266061 ,China
   Center for Ocean Mega‐Science, Chinese Academy of Sciences Qingdao266071 ,China
   Université Paris‐Saclay CNRS GEOPS 91405 Orsay ,France
   Institute of Earth and Planetary Sciences ,University College London and Birkbeck University of London Gower Street LondonWC1E 6BT, UK
   IFREMER, Marine Geoscience Unit, F‐29280 Plouzané ,France
   LSCE/IPSL, CEA‐CNRS‐UVSQ Université Paris‐Saclay F‐91191 Gif‐sur‐Yvette, France
   Key Laboratory of Ocean Circulation and Waves, Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 ,China
C2 CHINESE ACAD SCI, CHINA
   QNLM, CHINA
   CHINESE ACAD SCI, CHINA
   UNIV PARIS SACLAY, FRANCE
   UNIV COLL LONDON, UK
   IFREMER, FRANCE
   IPSL, FRANCE
   CHINESE ACAD SCI, CHINA
SI BREST
SE PDG-REM-GEOOCEAN-ASTRE
UM GEO-OCEAN
IN WOS Ifremer UMR
   copubli-france
   copubli-europe
   copubli-univ-france
   copubli-int-hors-europe
   copubli-sud
IF 5.2
TC 4
UR https://archimer.ifremer.fr/doc/00800/91222/96970.pdf
   https://archimer.ifremer.fr/doc/00800/91222/96971.pdf
LA English
DT Article
DE ;neodymium (Nd) isotope;Indian Summer Monsoon;Antarctic Intermediate Water
AB The relationship between ocean circulation and monsoon systems over orbital to sub-millennial timescales is a crucial but poorly-constrained component of the climate system. Here, using foraminiferal and detrital neodymium (Nd) isotope records from the intermediate-depth northern Indian Ocean, we provide new evidence revealing that both monsoon-driven weathering inputs and water mass advection from the Southern Ocean influenced past seawater Nd isotope changes in this region. Our results suggest that Indian Summer Monsoon weakening coincided with enhanced northward Antarctic Intermediate Water (AAIW) advection during the last deglaciation, reflecting a strong interhemispheric coupling. In contrast, the Early Holocene was characterised by enhanced monsoon strength but persistently strong AAIW inflow, indicating a relationship in the opposite sense. These differing interhemispheric relationships indicate asynchronous changes in the global atmosphere – ocean – climate system, and may represent a previously unrecognised component of the ocean-atmosphere reorganization during the deglacial to Holocene transition. Key Points We present a 17 kyr record of foraminiferal Nd isotopes from the intermediate-depth northern Indian Ocean with a resolution of ∼200 years Both regional Himalayan weathering inputs and intermediate water advection from the Southern Ocean influenced the record Different interhemispheric relationships are revealed between AAIW and the ISM during the last deglaciation compared to the Early Holocene Plain Language Summary Deciphering the interactions between processes in the Northern and Southern hemispheres is crucial for understanding the mechanisms of paleoclimate change, and therefore for predicting future climate evolution. Resolving the nature of such interactions requires high-resolution datasets from key components of the system. To this end, we present a new intermediate-depth foraminiferal neodymium (Nd) isotope record from the Indian Ocean covering the last 17,000 years at an unprecedented resolution of ∼200 years. Variability in this Nd isotope record reflects both changes in regional Nd inputs related to continental weathering driven by the Indian Summer Monsoon (ISM), and changes in the Nd signal carried northwards from the Southern Ocean by Antarctic Intermediate Water (AAIW). By disentangling these continental weathering and ocean circulation signals, we can compare Northern and Southern Hemisphere climate processes on sub-millennial timescales. We found that ISM weakening coincided with enhanced northward AAIW advection during the last deglaciation, whereas enhanced monsoonal activity was accompanied by persistently strong intermediate water inflow during the Early Holocene. This variable interhemispheric connection between the summer monsoon and intermediate water advection may have played a crucial role in the last deglacial climate transition. 
PY 2022
PD NOV
SO Geophysical Research Letters
SN 0094-8276
PU American Geophysical Union (AGU)
VL 49
IS 21
UT 000888513600001
DI 10.1029/2022GL100003
ID 91222
ER

EF