1. “What Can Dust Reveal about Past Climates
“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 #  

2. http://la. climatologie. free. fr/troposphere/troposphere1-english

3. http://swapsushias. blogspot

4. http://tnhsprgteam. blogspot

5. Conditions change over time for a variety of reasons

6. Monsoons Summer—rainy season Winter— dry season

9. Dust Aerosols with diameters below 10 µm
Estimates on the order of between 1,000 and 3,000 Tg yr–1 
Asian dust emissions: about 30% re-deposited onto the deserts, 20% is transported over regional scales, 50% is subject to long-range transport to the Pacific Ocean and beyond.
Asian dust continuous source that dominates background dust in west coast of the USA
Can provide nutrients (Fe, Zn, P) and ballast materials in the ocean
May impact atmospheric circulation and reflective effects

10. Dust is carried over the ocean across the globe

11. How Does Dust Affect Earth’s Albedo?
Refers to how much of the incoming solar radiation is reflected back into space
Increased dust  more reflection (higher albedo)  cooler temperatures
Clearer skies  lower albedo  warmer temperatures

12. How Does Dust Affect Clouds?
Cloud formation requires: (1) moisture; (2) cooling; and (3) a surface on which to condense
Dust can be cloud condensation nuclei More dust –> more cloud cover  cooling

13. Scientific Ocean Drilling JOIDES Resolution (“JR”)

15. Marcus G. Langseth (LDEO Marine Ops)
Earlier LDEO Vessels

16. LDEO Core Repository http://www.ldeo.columbia.edu/core-repository

17. Ice-Rafted Debris
Solid particles carried to sea on ice breaking off glaciers and ice sheets
Sink when their ‘rafts’ melt
Presence in deep-sea sediments indicate paleo-ocean circulation
Of special interest for
Atlantic Meridional Overturning Circulation (AMOC)

18. Ice cores from the Arctic and Antarctic

19. “Paleoclimate Proxies”
Cannot make direct measurements of past climate conditions, but have methods that provide strong indications
Examples: O16/O18 ratios Th230/Th Foraminifera Tree rings, pollen, corals

20. Finally, Geologic Time Holocene (last 10,000 years)
Pleistocene (10,000 – 2 my) “Ice Ages” Last Glacial Maximum (LGM) 18,000 yr ago Interglacial-Glacial