Deglacial Tropical Atlantic subsurface warming links ocean circulation variability to the West African Monsoon
| Autor: | Ping Chang, Feng He, Andrew O. Parker, Matthew W. Schmidt, Link Ji |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Multidisciplinary
010504 meteorology & atmospheric sciences Ocean current lcsh:R lcsh:Medicine Tropical Atlantic 010502 geochemistry & geophysics Monsoon 01 natural sciences Article Sea surface temperature Oceanography 13. Climate action Deglaciation Thermohaline circulation lcsh:Q 14. Life underwater Younger Dryas lcsh:Science Geology 0105 earth and related environmental sciences Teleconnection |
| Zdroj: | Scientific Reports Scientific Reports, Vol 7, Iss 1, Pp 1-11 (2017) |
| ISSN: | 2045-2322 |
| Popis: | Multiple lines of evidence show that cold stadials in the North Atlantic were accompanied by both reductions in Atlantic Meridional Overturning Circulation (AMOC) and collapses of the West African Monsoon (WAM). Although records of terrestrial change identify abrupt WAM variability across the deglaciation, few studies show how ocean temperatures evolved across the deglaciation. To identify the mechanism linking AMOC to the WAM, we generated a new record of subsurface temperature variability over the last 21 kyr based on Mg/Ca ratios in a sub-thermocline dwelling planktonic foraminifera in an Eastern Equatorial Atlantic (EEA) sediment core from the Niger Delta. Our subsurface temperature record shows abrupt subsurface warming during both the Younger Dryas (YD) and Heinrich Event 1. We also conducted a new transient coupled ocean-atmosphere model simulation across the YD that better resolves the western boundary current dynamics and find a strong negative correlation between AMOC strength and EEA subsurface temperatures caused by changes in ocean circulation and rainfall responses that are consistent with the observed WAM change. Our combined proxy and modeling results provide the first evidence that an oceanic teleconnection between AMOC strength and subsurface temperature in the EEA impacted the intensity of the WAM on millennial time scales. |
| Databáze: | OpenAIRE |
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