“What Can Dust Reveal about Past Climates?”
with Jerry McManus, Gisela Winckler, and Allison Jacobel
Originally presented 22 Oct 2016 (Morningside Campus)
Support in part by National Science Foundation Award #1502889
Windblown dust plays important roles in influencing and recording climate change. In the atmosphere, dust contributes to the planetary albedo and serves as cloud condensation nuclei. In the ocean, dust may fertilize biological productivity through the addition of crucial trace nutrients, and provide ballast for the sinking of particles, enhancing carbon export from the surface ocean and drawing down atmospheric CO2. In deep-sea sediments, the amount, location and type of dust deposition provide clues for reconstructing its past sources, pathways, magnitude and removal processes. These removal processes particularly include the shifting rain belts of the inter-tropical convergence zone (ITCZ) that follows the thermal equator over the tropical ocean.
This workshop shares results from projects examining variations in dust deposition throughout the last 150,000 years in the west-central Pacific and elsewhere. During this interval, the Earth’s climate shifted from full glaciation to one of the warmest interglacials in the last million years. Following that peak interglacial, global climate varied through multiple 20ky cycles while trending toward a return to full glacial conditions at the last glacial maximum before the last deglaciation and Holocene interglacial. Analyses will be made using sediments from a suite of cores recently recovered from the Line Islands ridge, a roughly north-south transect across the modern ITCZ near 160 °W, as well as in other scientific ocean drilling sites and Antarctica.
JERRY McMANUS (Home Page)
Professor of Geochemistry in the Columbia University Department of Earth and Environmental Sciences
GISELA WINCKLER (Home Page)
Lamont Research Professor, Division of Geochemistry
Related Articles and Videos
“Large Deglacial Shifts of the Pacific Intertropical Convergence Zone” — Jacobel et al.
“Currents, Conveyors, and Climate Change” — 2010 LDEO Public Lecture by Jerry McManus
(Source: MODIS Science Team image from Dust for Kids)
Global winds and climate zones, El Nino-La Nina patterns, Ice Age climate cycles, and ocean sediments are important components of middle and high school Earth Science core curricula. The scientific investigation results shared in this workshop will enhance teacher understanding of these topics, as well as support such NGSS Disciplinary Core Ideas as ESS2 Weather and Climate, ESS3 Global Climate Change, PS2 Forces & Motion and Stability & Instability, and PS3 Energy in Chemical processes and Everyday Life. We will also provide authentic examples of Science and Engineering Practices, Cross-Cutting Concepts, and the Nature of Science.
“Ice Core–Dust and Climate Reconstruction” provides a modification of a laboratory investigation used with Columbia University undergraduates in EESC W2100 “Earth’s Environmental Systems: Climate.” It provides an opportunity to learn important scientific concepts using real data, and serves as an example of modern college-level instruction.