Journal cover Journal topic
Climate of the Past An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/cp-2017-75
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
20 Jun 2017
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Climate of the Past (CP).
Hybrid insolation forcing of Pliocene monsoon dynamics in West Africa
Rony R. Kuechler, Lydie M. Dupont, and Enno Schefuß MARUM – Center for Marine Environmental Sciences, University of Bremen, Leobener Str. 8, 28359 Bremen, Germany
Abstract. The Pliocene is regarded as a potential analogue for future climate with conditions generally warmer-than-today and higher-than-preindustrial atmospheric CO2 levels. Here we present the first orbitally resolved records of continental hydrology and vegetation changes from West Africa for two Pliocene time intervals (5.0–4.6 Ma, 3.6–3.0 Ma). Our results indicate that changes in local insolation alone are insufficient to explain the full degree of hydrologic variations. Generally two modes of interacting insolation forcings are observed: during eccentricity maxima, when precession was strong, the West African monsoon was driven by summer insolation; during eccentricity minima, when precession-driven variations in local insolation were minimal, obliquity-driven changes in the summer latitudinal insolation gradient became dominant. This hybrid monsoonal forcing concept explains orbitally-controlled tropical climate changes, incorporating the forcing mechanism of latitudinal gradients for the Pliocene, which probably increased in importance during subsequent Northern Hemisphere glaciations.

Citation: Kuechler, R. R., Dupont, L. M., and Schefuß, E.: Hybrid insolation forcing of Pliocene monsoon dynamics in West Africa, Clim. Past Discuss., https://doi.org/10.5194/cp-2017-75, in review, 2017.
Rony R. Kuechler et al.
Rony R. Kuechler et al.
Rony R. Kuechler et al.

Viewed

Total article views: 341 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
255 79 7 341 4 8

Views and downloads (calculated since 20 Jun 2017)

Cumulative views and downloads (calculated since 20 Jun 2017)

Viewed (geographical distribution)

Total article views: 341 (including HTML, PDF, and XML)

Thereof 339 with geography defined and 2 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 18 Oct 2017
Publications Copernicus
Download
Short summary
Measuring Deuterium and stable carbon isotopes of higher plant wax extracted from marine sediments offshore of Mauretania, we recovered a record of hydrology and vegetation change in West Africa for two Pliocene intervals; 5.0–4.6 Ma and 3.6–3.0 Ma. We find that changes in local summer insolation cannot fully explain the variations in the West African monsoon and that latitudinal insolation and temperature gradients are important drivers of tropical monsoon systems.
Measuring Deuterium and stable carbon isotopes of higher plant wax extracted from marine...
Share