Downscaling Last Glacial Maximum climate over southern Africa

Francois A. Engelbrecht, Curtis W. Marean, Richard M. Cowling, Christien J. Engelbrecht, Frank H. Neumann, Louis Scott, Ramapulana Nkoana, David O'Neal, Erich Fisher, Eric Shook, Janet Franklin, Marcus Thatcher, John L. McGregor, Jacobus Van der Merwe, Zane Dedekind, Mark Difford

Research output: Contribution to journalArticlepeer-review

18 Scopus citations

Abstract

We conducted the first dynamic downscaling of Last Glacial Maximum (LGM) climate over southern Africa using a regional climate model. Eight coupled global climate model (CGCM) projections of LGM climate were downscaled to 8 km resolution, and compared to a downscaling of present-day climate. It is projected that temperatures were significantly lower during the LGM compared to the present-day, with annual average temperatures 4–6 °C lower along the eastern escarpment, south-north aligned Cape Fold Mountains and western escarpment. Southern Africa is projected to have been generally wetter during the LGM, with a significant extension in the northward reach of frontal rainfall. The largest rainfall increases are projected for the south-north aligned Cape Fold Mountains and the western escarpment of South Africa, but with rainfall decreases projected for the Cape south coast region. Rainfall seasonality is projected to have been significantly different from that of the present-day, with an all-year rainfall region plausibly extending as far north and east as the present-day Free State and Gauteng provinces of South Africa. Evaluations of the downscalings against key published proxy records for the LGM from southern Africa suggest good agreement and few deviations.

Original languageEnglish (US)
Article number105879
JournalQuaternary Science Reviews
Volume226
DOIs
StatePublished - Dec 15 2019

Bibliographical note

Funding Information:
This research was supported by National Research Foundation (NRF) African Origins Platform Funding (Grant Numbers: 82634 , 85903 ). Any opinions, findings, and conclusions are those of the author(s) and the NRF does not accept any liability in regard thereto. The lead author received support from the NRF in South Africa through its Incentive Funding for Rated Researchers. Supplementary funding was provided by the Hyde Family Foundations , Institute of Human Origins , and the National Science Foundation (NSF) BCS-0524087 and BCS-1138073 (to Marean). Marean recognizes the support of a grant from the John Templeton Foundation to the Institute of Human Origins at Arizona State University . The opinions expressed in this publication are those of the author(s) and do not necessarily reflect the views of the John Templeton Foundation or any other granting agency. The model simulations were performed on the super computers of the Centre for High performance Computing (CHPC) in South Africa and the Extreme Science and Engineering Discovery Environment (XSEDE) Stampede system at the Texas Advanced Computing Centre (TACC). The latter allocation was available through the NS grant number ACI-1548562, project allocation number DBS140003. The climate simulations were partially funded through CSIR Parliamentary Grant and Thematic funding related to the development of the Variable-resolution Earth System Model (VrESM). We acknowledge the modelling groups, the Program for Climate Model Diagnosis and Intercomparison (PCMDI) and the World Climate Research Programme's (WCRP's) Working Group on Coupled Modelling (WGCM) for their roles in making available the WCRP CMIP5 multi-model dataset.

Publisher Copyright:
© 2019

Keywords

  • Climate dynamics
  • Palaeo-agulhas plain
  • Palaeoclimate modelling
  • Pleistocene
  • Rainfall seasonality
  • Regional climate modelling
  • Southern Africa
  • Vegetation dynamics

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