FN Archimer Export Format
PT J
TI Fates of paleo Antarctic Bottom Water during the early Eocene ― based on a Lagrangian analysis of IPSL‐CM5A2 climate model simulations
BT 
AF Zhang, Yurui
   Grima, Nicolas
   Huck, Thierry
AS 1:1,2;2:3;3:3;
FF 1:PDG-ODE-LOPS-OH;2:;3:;
C1 Univ Brest, CNRS, IRD, Ifremer, Laboratoire d'Océanographie Physique et Spatiale (LOPS), IUEM Brest France
   Xiamen Univ, Coll Ocean & Earth Sci, Xiamen, Peoples R China
   Univ Brest, CNRS, IRD, Ifremer, Laboratoire d'Océanographie Physique et Spatiale (LOPS), IUEM Brest France
C2 IFREMER, FRANCE
   UNIV XIAMEN, CHINA
   CNRS, FRANCE
SI BREST
SE PDG-ODE-LOPS-OH
UM LOPS
IN WOS Ifremer UMR
   WOS Cotutelle UMR
   copubli-france
   copubli-int-hors-europe
   copubli-sud
IF 3.992
TC 2
UR https://archimer.ifremer.fr/doc/00663/77556/79448.pdf
   https://archimer.ifremer.fr/doc/00663/77556/79449.docx
LA English
DT Article
DE ;the early Eocene;paleo-Antarctic Bottom Water;Lagrangian analysis;deepwater obduction;Equtorial and tropical upwelling;Ekman pumping
AB Both deepwater formation and the obduction processes converting dense deepwater to lighter surface water are the engine for the global meridional overturning circulation (MOC). Their spatio‐temporal variations effectively modify the ocean circulation and related carbon cycle, which affects climate evolution throughout geological time. Using early‐Eocene bathymetry and enhanced atmospheric CO2 concentration, the IPSL‐CM5A2 climate model has simulated a well‐ventilated Southern Ocean associated with a strong anticlockwise MOC. To trace the fates of these paleo Antarctic Bottom Water (paleo‐AABW), we conducted Lagrangian analyses using these IPSL‐CM5A2 model results and tracking virtual particles released at the lower limb of the MOC, defined as an initial section at 60°S below 1900m depth. Diagnostic analysis of these particles trajectories reveals that most paleo‐AABW circulates back to the Southern Ocean through either the initial section (43%) or the section above (31%); the remaining (>25%) crossing the base of the mixed layer mostly in tropical regions (up to half). The majority of water parcels ending in the mixed layer experience negative density transformations, intensified in the upper 500m and mostly occurring in tropical upwelling regions, with a spatial pattern consistent with the wind‐driven Ekman pumping, largely determined by the Eocene wind stress and continental geometry. In the same way as present‐day North Atlantic Deep Water upwells in the Southern Ocean, our results suggest that the strong tropical and equatorial upwelling during the Eocene provides an efficient pathway from the abyss to the surface, but at much higher temperature, with potential implications for the oceanic carbon cycle. 
PY 2021
PD JAN
SO Paleoceanography And Paleoclimatology
SN 2572-4517
PU American Geophysical Union (AGU)
VL 36
IS 1
UT 000613332600005
DI 10.1029/2019PA003845
ID 77556
ER

EF