Preprints
https://doi.org/10.5194/cp-2020-141
https://doi.org/10.5194/cp-2020-141

  17 Nov 2020

17 Nov 2020

Review status: this preprint is currently under review for the journal CP.

Holocene climatic changes in the Westerly-Indian Monsoon realm and its anthropogenic impact

Nicole Burdanowitz1, Tim Rixen1,2, Birgit Gaye1, and Kay-Christian Emeis1,3 Nicole Burdanowitz et al.
  • 1Institute for Geology, Universität Hamburg, Bundesstraße 55, 20146 Hamburg, Germany
  • 2Leibniz-Zentrum für Marine Tropenforschung (ZMT), Fahrenheitstraße 6, 28359 Bremen, Germany
  • 3Institute of Coastal Research, Helmholtz Center Geesthacht, Max-Planck-Straße 1, 21502 Geesthacht, Germany

Abstract. The Indian Summer Monsoon (ISM) with its rainfall is the lifeline for people living on the Indian subcontinent today and possibly was the driver of the rise and fall of early agricultural societies in the past. Intensity and position of the ISM have shifted in response to orbitally forced thermal land-ocean contrasts. At the northwestern monsoon margins, interactions between the subtropical westerly jet (STWJ) and the ISM constitute a tipping element in the Earth's climate system, because their non-linear interaction may be a first-order influence on rainfall. We reconstructed marine sea surface temperature (SST), supply of terrestrial material and vegetation changes from a very well-dated sediment core from the northern Arabian Sea to reconstruct the STWJ-ISM interaction. The Holocene record (from 11,000 years) shows a distinct, but gradual, southward displacement of the ISM in the Early to Mid-Holocene, increasingly punctuated by phases of intensified STWJ events that are coeval with interruptions of North Atlantic overturning circulation (Bond events). Effects of the non-linear interactions culminate between 4.6–3 ka BP, marking a climatic transition period during which the ISM shifted southwards and the influence of SWTJ became prominent. The lithogenic input shows an up to 4-fold increase after this time period signaling the strengthened influence of agricultural activities of the Indus civilization with enhanced erosion of soils amplifying the impact of Bond events and adding to the marine sedimentation rates adjacent to the continent.

Nicole Burdanowitz et al.

 
Status: final response (author comments only)
Status: final response (author comments only)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Login for authors/editors] [Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Nicole Burdanowitz et al.

Data sets

Grain sizes and geochemistry of Holocene sediments in the Arabian Sea. Burdanowitz, Nicole, Gaye, Birgit, Hilbig, Lea, Lahajnar, Niko, Lückge, Andreas, Rixen, Tim, and Emeis, Kay-Christian https://doi.org/10.1594/PANGAEA.900973

Nicole Burdanowitz et al.

Viewed

Total article views: 480 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
328 142 10 480 7 10
  • HTML: 328
  • PDF: 142
  • XML: 10
  • Total: 480
  • BibTeX: 7
  • EndNote: 10
Views and downloads (calculated since 17 Nov 2020)
Cumulative views and downloads (calculated since 17 Nov 2020)

Viewed (geographical distribution)

Total article views: 379 (including HTML, PDF, and XML) Thereof 373 with geography defined and 6 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 03 Mar 2021
Download
Short summary
To understand the interaction of the Westerlies and Indian Summer Monsoon (ISM) during the Holocene, we used paleoenvironmental reconstructions by using a sediment core from the NE Arabian Sea. We found a climatic transition period between 4.6–3 ka BP during which the ISM shifted southwards and the influence of Westerlies became prominent. Our data indicate a stronger influence of agriculture activities and enhanced soil erosion adding to the impact of Bond events after this transition period.