1. Alley’s ‘Wally Was Right: Predictive Ability of the North Atlantic “Conveyor Belt” Hypothesis for Abrupt Climate Change’ Jake Leech 29 Aug 08

2. Bestiary

3. Wally’s Arguments Greenland proxies all show abrupt climate change Greenland data matches Europe data Data matches expectations from North Atlantic SST changes MOC switching is possible Data shows ocean circulation changes

4. Ice core data

5. Hemispheric See-Saw Modelled climate patterns seem to match Voelker data set

6. See Saw in Data

7. Response of MOC to freshwater

8. Sea Ice and Seasonality

9. Wally’s data Young, surface waters are depleted in Cd and C-12, and enriched in C-14 SH water is “older” During cold periods, NH sediments are “older”

10. Jean’s Data Benthic forams have heavier oxygen isotopes in colder water and saltier water, and therefore in denser water. Density profiles can be used to reconstruct geostrophic flow through the Florida Straits, which shows changes in MOC.

11. Jerry’s Data Water is stripped of Pa and Th before entering the North Atlantic Thorium is stripped out of the water within 20-40 years, before being exported Protactinium is stripped out of the water within 100-200 years, after being exported.

12. Jerry’s Data vs. Forams

13. Caveats Background state is important. Freshwater forcing? Cooling events and freshwater pulses are correlated, but which causes which? 1500 year oscillation?