TY  - JOUR
A1  - Deplazes, Gaudenz
A1  - Lueckge, Andreas
A1  - Peterson, Larry C.
A1  - Timmermann, Axel
A1  - Hamann, Yvonne
A1  - Hughen, Konrad A.
A1  - Roehl, Ursula
A1  - Laj, Carlo
A1  - Cane, Mark A.
A1  - Sigman, Daniel M.
A1  - Haug, Gerald H.
T1  - Links between tropical rainfall and North Atlantic climate during the last glacial period
JF  - Nature geoscience
N2  - During the last glacial period, the North Atlantic region experienced pronounced, millennial-scale alternations between cold, stadial conditions and milder interstadial conditions-commonly referred to as Dansgaard-Oeschger oscillations-as well as periods of massive iceberg discharge known as Heinrich events(1). Changes in Northern Hemisphere temperature, as recorded in Greenland(2-4), are thought to have affected the location of the Atlantic intertropical convergence zone(5,6) and the strength of the Indian summer monsoon(7,8). Here we use high-resolution records of sediment colour-a measure of terrigenous versus biogenic content-from the Cariaco Basin off the coast of Venezuela and the Arabian Sea to assess teleconnections with the North Atlantic climate system during the last glacial period. The Cariaco record indicates that the intertropical convergence zone migrated seasonally over the site during mild stadial conditions, but was permanently displaced south of the basin during peak stadials and Heinrich events. In the Arabian Sea, we find evidence of a weak Indian summer monsoon during the stadial events. The tropical records show a more variable response to North Atlantic cooling than the Greenland temperature records. We therefore suggest that Greenland climate is especially sensitive to variations in the North Atlantic system-in particular sea-ice extent-whereas the intertropical convergence zone and Indian monsoon system respond primarily to variations in mean Northern Hemisphere temperature.
Y1  - 2013
U6  - https://doi.org/10.1038/ngeo1712
SN  - 1752-0894
VL  - 6
IS  - 3
SP  - 213
EP  - 217
PB  - Nature Publ. Group
CY  - New York
ER  - 
TY  - JOUR
A1  - Deplazes, Gaudenz
A1  - Lückge, Andreas
A1  - Stuut, Jan-Berend W.
A1  - Paetzold, Jürgen
A1  - Kuhlmann, Holger
A1  - Husson, Dorothee
A1  - Fant, Mara
A1  - Haug, Gerald H.
T1  - Weakening and strengthening of the Indian monsoon during Heinrich events and Dansgaard- Oeschger oscillations
JF  - Paleoceanography
N2  - The Dansgaard-Oeschger oscillations and Heinrich events described in North Atlantic sediments and Greenland ice are expressed in the climate of the tropics, for example, as documented in Arabian Sea sediments. Given the strength of this teleconnection, we seek to reconstruct its range of environmental impacts. We present geochemical and sedimentological data from core SO130-289KL from the Indus submarine slope spanning the last similar to 80 kyr. Elemental and grain size analyses consistently indicate that interstadials are characterized by an increased contribution of fluvial suspension from the Indus River. In contrast, stadials are characterized by an increased contribution of aeolian dust from the Arabian Peninsula. Decadal-scale shifts at climate transitions, such as onsets of interstadials, were coeval with changes in productivity-related proxies. Heinrich events stand out as especially dry and dusty events, indicating a dramatically weakened Indian summer monsoon, potentially increased winter monsoon circulation, and increased aridity on the Arabian Peninsula. This finding is consistent with other paleoclimate evidence for continental aridity in the northern tropics during these events. Our results strengthen the evidence that circum-North Atlantic temperature variations translate to hydrological shifts in the tropics, with major impacts on regional environmental conditions such as rainfall, river discharge, aeolian dust transport, and ocean margin anoxia.
KW  - Indian Monsoon
KW  - Arabian Sea
KW  - XRF
KW  - Dansgaard-Oeschger oscillations
KW  - Heinrich events
KW  - Sediment Transport
Y1  - 2014
U6  - https://doi.org/10.1002/2013PA002509
SN  - 0883-8305
SN  - 1944-9186
VL  - 29
IS  - 2
SP  - 99
EP  - 114
PB  - American Geophysical Union
CY  - Washington
ER  -