Meets: Tuesdays and Thursdays 9:30-10:45 am, Benson Earth Sciences 355 Course description: An understanding of the modes and mechanisms of past climate variability is a vital prerequisite for understanding our current and future climate. Past changes in oceanic and atmospheric circulation are known to have far exceeded the range of variability observed during the instrumental period. Such past changes offer important insights into the basic workings of the Earth’s climate, including its carbon cycle. In addition, dramatic paleoclimate shifts have occurred over periods as short as a decade, a time scale of obvious societal interest. Could similar shifts recur in a future “Greenhouse” world? We will examine scientific tools, data, and theories related to the dramatically varied past climate of the Earth. Focus will be on marine records of climate change and ocean circulation, but ice core and continental archives will also be discussed. Course will cover the Cretaceous Period to the present, with particular emphasis on the past 150,000 years (the last glacial-interglacial cycle). This will be a lecture course, with readings from texts and research journals. Grading: 50% homework, 20% midtern exam, 20% final exam, 10% class participation (includes attendance). Undergraduate and graduate homework assignments and exams will be slightly different, and the two groups will be evaluated separately. Homework: Six homework assignments will allow students to apply what they have learned in class to practical problems, and may include critical reading and writing skills. Math will generally be limited to algebra, plus a little calculus. Homework assignments are to be handed in during class, and late assignments will lose 10% credit per day (not per class meeting). Recommended textbooks: Bradley, Paleoclimatology: Reconstructing Climates of the Quaternary, 2nd Ed., 1999: emphasizes methods of paleoclimate reconstruction, and is limited to Quaternary timescales. Ruddiman, Earth's Climate: Past and Future, 1st Ed., 2001: emphasizes climate mechanisms and history, over the Cenozoic (and beyond). Frequent readings from both books will reinforce and supplement lecture material. Both are on 2-hr reserve in Earth Sciences Library and INSTAAR Reading Room. Syllabus with Critical Concepts
Professor: Tom Marchitto, tom.marchitto@colorado.edu
Office Hours: Tuesdays 11:00-12:00, Benson 435, or by appointment
3 Credits
Counts toward the Graduate Certificate in OceanographyClass Schedule
click on lecture title for PowerPoint file
T 8/28:
Intro to paleoceanography and paleoclimatology
Th 8/30:
Overview of radiative balance and atmospheric circulation
Recommended Reading: Bradley 2.4 and/or Ruddiman pp. 19-39
T 9/4: ICP- No class
Th 9/6: ICP- No class
T 9/11:
Overview of ocean circulation
Recommended Reading: Ruddimann pp. 39-44
Th 9/13:
Milankovitch orbital theory
Reading: Bradley 2.6 and/or Ruddiman pp. 175-188
Berger and Loutre database of orbital parameters
Homework 1 Due Thurs 9/20
Homework 1 Key
T 9/18:
Oxygen isotopes: Paleotemperature and global ice volume
Reading: Bradley 5.2-5.2.3; 6.3-6.3.1
Classic Reading: Dansgaard and Tauber, Glacier oxygen-18 content and Pleistocene ocean temperatures, Science, 166: 499-502, 1969. (on reserve)
Th 9/20:
Milankovitch confirmed: Spectral analysis and SPECMAP
Reading: Bradley 6.3.2-6.3.4
Classic Reading: Hays et al., Variations in the Earth's orbit: Pacemeaker of the Ice Ages, Science, 194: 1121-1132, 1976. (on reserve)
T 9/25:
Marine microfossils and paleoecological factor analysis (CLIMAP)
Reading: Bradley 6.4-6.4.3
Classic Reading: CLIMAP Project Members, The surface of the ice-age Earth, Science, 191: 1131-1137, 1976. (on reserve)
Th 9/27:
Ocean temperatures from alkenones and carbonate trace elements
Reading: Bradley 6.5
Homework 2 Due Thurs 10/4
T 10/2:
Climate information from non-biogenic marine sediments
Reading: Bradley 6.7 and Ruddiman pp. 334-337; 345-347
Classic Reading: Bond et al., Correlation between climate records from North Atlantic sediments and Greenland ice, Nature, 365: 143-147, 1993. (on reserve)
Good Review Paper: Hemming, Heinrich events: Massive late Pleistocene detritus layers of the North Atlantic and their global climate imprint, Review of Geophysics, 42: RG1005, doi:10.1029/2003RG000128, 2004. (available by request)
Th 10/4:
Ice cores: Glaciology and water isotopes
Reading: Bradley 5.2.4; 5.3-5.4.2; 5.4.4-5.4.7
EPICA Deuterium Paper: EPICA community members, Eight glacial cycles from an Antarctic ice core, Nature, 429: 623-628, 2004.
T 10/9:
Ice cores: Ancient atmospheres
Reading: Bradley 5.2.5; 5.4.3
EPICA CO2 Paper: Siegenthaler et al., Stable Carbon Cycle-Climate Relationship During the Late Pleistocene, Science, 310: 1313-1317, 2005.
Th 10/11:
Terrestrial paleoclimate: Glacial/periglacial features
Reading: Bradley 7.2-7.4.2; 7.6-7.6.3
Homework 3 Due Thurs 10/18
T 10/16:
Pollen and tree rings
Reading: Bradley Chapters 9 & 10 (if interested)
Th 10/18:
Millennial-scale climate change and North Atlantic Deep Water
Reading: Ruddiman pp. 345-348 and Bradley 12.5
Good Review Paper:
Stocker, Past and future reorganizations in the climate system, Quaternary Science Reviews, 19: 301-319, 2000.
T 10/23: Midterm Exam
Midterm Preview
Midterm Key
Th 10/25:
Paleonutrients and deep ocean circulation
Reading: Bradley 6.9-6.10.1
Good (hopefully) Review Paper: Marchitto and Broecker, Deep water mass geometry in the glacial Atlantic Ocean: A review of constraints from the paleonutrient proxy Cd/Ca, Geochemistry, Geophysics, Geosystems, 7(12), Q12003, doi:10.1029/2006GC001323, 2006.
T 10/30:
U/Th dating and sea level history
Reading: Bradley 6.10.2 and/or Ruddiman pp. 302-309
Classic Reading: Fairbanks, A 17,000-year glacio-eustatic sea level record: influence of glacial melting rates on the Younger Dryas event and deep ocean circulation, Nature, 342: 637-642, 1989. (on reserve)
Th 11/1:
Radiocarbon: Dating tool and marine tracer
Reading: Bradley 3.2.1-3.2.1.7
Radiocarbon calibration database
Homework 4 Due Thurs 11/8
T 11/6:
Paleo-monsoon and paleo-ENSO
Reading: Ruddiman pp. 194-205
Th 11/8:
Cenozoic atmospheric CO2 and tectonics
Reading: Ruddiman pp. 116-127
T 11/13:
Glacial-interglacial atmospheric CO2 and ocean chemistry
Reading: Ruddiman pp. 240-253
Good Review Paper: Sigman and Boyle, Glacial/interglacial variations in atmospheric carbon dioxide, Nature, 407: 859-869, 2000.
Th 11/15:
Climate models
Reading: Bradley 12.1-12.3 and/or Ruddiman pp. 71-79
EdGCM
Homework 5 Due Thurs 11/29
T 11/20: Fall Break- No class
Th 11/22: Fall Break- No class
T 11/27:
Late Cretaceous to Eocene (99-34 Ma): Greenhouse world
Reading: Ruddiman pp. 130-137
Th 11/29:
Oligocene to Miocene (34-5 Ma): Descent into the Icehouse
Reading: Ruddiman pp. 161-162; 166 (Burial of Organic Carbon); 208-209
T 12/4:
Plio-Pleistocene (past 5 Ma): Northern Hemisphere glaciation and appearance of humans
Reading: Ruddiman pp. 220-225; 266-272
Th 12/6:
Holocene (past 10 ka): Relative stability and dawn of agriculture
Reading: Ruddiman pp. 314-321; 391-394
Good Review Paper: Kaufman et al., Holocene thermal maximum in the western Arctic (0–180°W), Quaternary Science Reviews, 23: 529-560, 2004.
T 12/11:
Past 1000 yrs: Medieval Warm Period, Little Ice Age, and Anthropocene
Reading: Ruddiman pp. 355-357; 370-371; 376-381; 396-403
CDIAC greenhouse gas trends
GISS temperature trends
Th 12/13:
Future climate: 'Inevitable surprises?'
Reading: Ruddiman pp. 424-435
Intergovernmental Panel on Climate Change (IPCC4)
Arctic Climate Impact Assessment
US Climate Change Science Program
Final Exam: Monday 12/17, 4:30-7:00 pm
Final Preview