FN Archimer Export Format
PT J
TI African monsoon enhancement during the penultimate glacial period (MIS 6.5 similar to 170 ka) and its atmospheric impact
BT 
AF TISSERAND, Amandine
   MALAIZE, Bruno
   JULLIEN, Elsa
   ZARAGOSI, Sebastien
   CHARLIER, Karine
   GROUSSET, Francis
AS 1:1,2,3;2:1;3:1;4:1;5:1;6:1;
FF 1:;2:;3:;4:;5:;6:;
C1 Univ Bordeaux 1, EPOC, CNRS, UMR5805, F-33405 Talence, France.
   Bjerknes Ctr Climate Res, N-5007 Bergen, Norway.
   Univ Bergen, Dept Earth Sci, Bergen, Norway.
C2 UNIV BORDEAUX, FRANCE
   BCCR, NORWAY
   UNIV BERGEN, NORWAY
IF 3.644
TC 24
UR https://archimer.ifremer.fr/doc/00218/32937/31444.pdf
LA English
DT Article
CR MD 134 / PICABIA
BO Marion Dufresne
AB A reconstruction of northwest African summer monsoon strength during the cold marine isotopic stage (MIS) 6 indicates a link to the seasonal migration of the Intertropical Convergence Zone (ITCZ). High-resolution studies of eolian dust supply and sea surface temperature recorded in marine core MD03-2705, on the Mauritanian margin, provide a better understanding about the penultimate glacial history of northwestern African aridity/humidity and upwelling coastal activity. Today, site MD03-2705 experiences increased upwelling and dust flux during the winter months, when the ITCZ is in a southerly position. Analyses of foraminifera isotopic composition suggest that during MIS 6.5 (180 - 168 ka) the average position of the ITCZ migrated north, marked by an increase in the strength of the summer monsoon, which decreased eolian dust transport and the coastal upwelling activity. The northward migration is in phase with a specific orbital combination of a low precessional index with a high obliquity signal. High-resolution analysis of stable isotopes (delta(18)O and delta(13)C) and microscale resolution geochemical (Ti/Al and quartz grain counts) determinations reveal that the transition between monsoonal humid (MIS 6.5) and dry (MIS 6.4) conditions has occurred in less than 1.3 ka. Such rapid changes suggest a nonlinear link between the African monsoonal rainfall system and environmental changes over the continent. This study provides new insights about the influence of vegetation and oceanic temperature feedbacks on the onset of African summer monsoon and demonstrates that, during the penultimate glacial period, changes in tropical dynamics had regional and global impacts.
PY 2009
PD JUL
SO Paleoceanography
SN 0883-8305
PU Amer Geophysical Union
VL 24
IS PA2220
UT 000267191600002
BP 1
EP 16
DI 10.1029/2008PA001630
ID 32937
ER

EF