Glacial to Holocene changes in trans-Atlantic Saharan dust transport and dust-climate feedbacks
Williams, Ross H.
Kinsley, Christopher W.
Ridley, David A.
Murray, Richard W.
deMenocal, Peter B.
MetadataShow full item record
Saharan mineral dust exported over the tropical North Atlantic is thought to have significant impacts on regional climate and ecosystems, but limited data exist documenting past changes in long-range dust transport. This data gap limits investigations of the role of Saharan dust in past climate change, in particular during the mid-Holocene, when climate models consistently underestimate the intensification of the West African monsoon documented by paleorecords. We present reconstructions of African dust deposition in sediments from the Bahamas and the tropical North Atlantic spanning the last 23,000 years. Both sites show early and mid-Holocene dust fluxes 40 to 50% lower than recent values and maximum dust fluxes during the deglaciation, demonstrating agreement with records from the northwest African margin. These quantitative estimates of trans-Atlantic dust transport offer important constraints on past changes in dust-related radiative and biogeochemical impacts. Using idealized climate model experiments to investigate the response to reductions in Saharan dust’s radiative forcing over the tropical North Atlantic, we find that small (0.15°C) dust-related increases in regional sea surface temperatures are sufficient to cause significant northward shifts in the Atlantic Intertropical Convergence Zone, increased precipitation in the western Sahel and Sahara, and reductions in easterly and northeasterly winds over dust source regions. Our results suggest that the amplifying feedback of dust on sea surface temperatures and regional climate may be significant and that accurate simulation of dust’s radiative effects is likely essential to improving model representations of past and future precipitation variations in North Africa.
© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Science Advances 2 (2016): e1600445, doi:10.1126/sciadv.1600445.
The following license files are associated with this item:
Except where otherwise noted, this item's license is described as Attribution-NonCommercial 4.0 International
Showing items related by title, author, creator and subject.
Feary, David A.; Burt, John A.; Bauman, Andrew G.; Al Hazeem, Shaker; Abdel-Moati, Mohamed A.; Al-Khalifa, Khalifa A.; Anderson, Donald M.; Amos, Carl; Baker, Andrew; Bartholomew, Aaron; Bentok, Rita; Cavalcante, Georgenes H.; Chen, Chaolun Allen; Coles, Steve L.; Dab, Koosha; Fowler, Ashley M.; George, David; Grandcourt, Edwin; Hill, Ross; John, David M.; Jones, David A.; Keshavmurthy, Shashank; Mahmoud, Huda; Moradi Och Tapeh, Mahdi; Mostafavi, Pargol Ghavam; Naser, Humood; Pichonz, Michel; Purkis, Sam; Riegl, Bernhard; Samimi-Namin, Kaveh; Sheppard, Charles; Samiei, Jahangir Vajed; Voolstra, Christian R.; Wiedenmann, Joerg (2013-02)Expert opinion was assessed to identify current knowledge gaps in determining future changes in Arabian/Persian Gulf (thereafter ‘Gulf’) coral reefs. Thirty-one participants submitted 71 research questions that were ...
Carter, William E.; Aubrey, David G.; Baker, Trevor; Boucher, Claude; LeProvost, Christian; Pugh, David T.; Peltier, W. R.; Zumberge, Mark A.; Rapp, Richard H.; Schultz, Robert E.; Emery, Kenneth O.; Enfield, David B. (Woods Hole Oceanographic Institution, 1989-08)Under the auspices of the International Association for Physical Sciences of the Ocean (IAPSO) a committee was established to identify the oceanographic and geophysical requirements for fixing Tide Gauge Bench Maries ...
David, John; Garrity, George M.; Greuter, Werner; Hawksworth, David L.; Jahn, Regine; Kirk, Paul M.; McNeill, John; Michel, Ellinor; Knapp, Sandra; Patterson, David J.; Tindall, Brian J.; Todd, Jonathan A.; Tol, Jan van; Turland, Nicholas J. (Pensoft, 2012-05-08)A set of terms recommended for use in facilitating communication in biological nomenclature is presented as a table showing broadly equivalent terms used in the traditional Codes of nomenclature. These terms are intended ...