Atlantic Meridional Overturning Circulation Influence on the Annual Mean Intertropical Convergence Zone Location in the Miocene

Abstract The Intertropical Convergence Zone (ITCZ) has an annual mean location north of the equator today. The factors determining this location and the evolution to its modern state are actively debated. Here we investigate how the Atlantic Meridional Overturning Circulation (AMOC) influences the I...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Xiaoqing Liu, Nicholas Herold, Matthew Huber
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2024
Subjects:
Geophysics. Cosmic physics
QC801-809
Arctic Archipelago
Canadian Arctic Archipelago
North Atlantic Deep Water
North Atlantic
Online Access:https://doi.org/10.1029/2024GL109159
https://doaj.org/article/700fc50979cd414e8f8dcc70a6e54521
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Summary:Abstract The Intertropical Convergence Zone (ITCZ) has an annual mean location north of the equator today. The factors determining this location and the evolution to its modern state are actively debated. Here we investigate how the Atlantic Meridional Overturning Circulation (AMOC) influences the ITCZ during the early‐to‐middle Miocene. By conducting a sensitivity study with an open Canadian Arctic Archipelago gateway, we show that North Atlantic Deep‐Water formation strengthens the AMOC, in alignment with Miocene North Atlantic ventilation proxies. A vigorous AMOC increases northward Atlantic Ocean heat transport and cross‐equatorial atmospheric energy transport shifts southwards to compensate, pushing the ITCZ northwards. Our study supports AMOC development as a strong contributor to the ITCZ's northern location today. Existing proxy‐based interpretations of ITCZ history are too sparse to strongly confirm these results. We predict a strong in‐phase relationship between AMOC strength and ITCZ's northward location, which should be testable in high resolution paleoclimate records.

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