TY  - JOUR
A1  - Sarr, Anta-Clarisse
A1  - Donnadieu, Yannick
A1  - Bolton, Clara T.
A1  - Ladant, Jean-Baptiste
A1  - Licht, Alexis
A1  - Fluteau, Frédéric
A1  - Laugié, Marie
A1  - Tardif-Becquet, Delphine
A1  - Dupont-Nivet, Guillaume
T1  - Neogene South Asian monsoon rainfall and wind histories diverged due to topographic effects
T2  - Nature geoscience
N2  - The drivers of the evolution of the South Asian Monsoon remain widely debated. An intensification of monsoonal rainfall recorded in terrestrial and marine sediment archives from the earliest Miocene (23-20 million years ago (Ma)) is generally attributed to Himalayan uplift. However, Indian Ocean palaeorecords place the onset of a strong monsoon around 13 Ma, linked to strengthening of the southwesterly winds of the Somali Jet that also force Arabian Sea upwelling. Here we reconcile these divergent records using Earth system model simulations to evaluate the interactions between palaeogeography and ocean-atmosphere dynamics. We show that factors forcing the South Asian Monsoon circulation versus rainfall are decoupled and diachronous. Himalayan and Tibetan Plateau topography predominantly controlled early Miocene rainfall patterns, with limited impact on ocean-atmosphere circulation. The uplift of the East African and Middle Eastern topography played a pivotal role in the establishment of the modern Somali Jet structure above the western Indian Ocean, while strong upwelling initiated as a direct consequence of the emergence of the Arabian Peninsula and the onset of modern-like atmospheric circulation. Our results emphasize that although elevated rainfall seasonality was probably a persistent feature since the India-Asia collision in the Paleogene, modern-like monsoonal atmospheric circulation only emerged in the late Neogene.
Y1  - 2022
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/64410
SN  - 1752-0894
SN  - 1752-0908
VL  - 15
IS  - 4
SP  - 314
EP  - 319
PB  - Nature Research
CY  - Berlin
ER  -