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GEOL 5700-11 - Super-Problems in Quaternary Climate

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LGM modeled buoyancy forcing

Atlantic Cd sections

Course description: A yearly investigation, in seminar format, of major problems in the study and understanding of Quaternary climate variation. Each year one or two major topics will be addressed, which may include: the physics and chemistry of the glacial ocean circulation; the theory and mechanics of glacial/interglacial atmospheric CO2 change; the origins of the 20, 40, and 100 kyr (Milankovitch) climate cycles; and resolving tropical climates during the last glacial maximum.

In Spring ’10, we will focus on the physics and chemistry of the glacial ocean circulation.

Expectations and grading: Students will be required to make presentations on assigned readings from both the historic and current research literature. There will be one or two discussion leaders per week, but everyone is responsible for reading the papers and participating in the discussion. Presentations should go beyond the papers at hand by providing relevant background material (including figures) that helps to place the papers in the context of previous studies. We are not looking for an exhaustive summary of the reading, but rather a framework from which the group can discuss and better understand the papers. In addition, each week one student will be assigned the role of "web gopher," and may be asked during class to retreive particular papers from the internet. Grades will be based on the quality of presentations (40%) and on overall participation, which includes attendance (60%).

Readings will be available either as online pdfs or as hardcopies on reserve in the INSTAAR Reading Room and the Geological Sciences Library.

Meets: Mondays 10 am - 12 pm, Mort Turner Room, INSTAAR (RL1 233)
Instructors:, scott.lehman@colorado.edu; , tom.marchitto@colorado.edu
Office Hours: By appointment
Credits: 2

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Schedule is tentative and subject to change

Week 1 (W 1/13, 3 pm, INSTAAR RL1 233): Organizational meeting

Week 2 (1/18): No Class (MLK Day)

Week 3 (1/25): Modern ocean circulation (instructor presentations by and ) and Early thinking about the glacial circulation
Required Reading: hardcopy also on reserve

Week 4 (2/1): Carbon-13 as a deep water tracer
Required Reading: (Ursula)
Required Reading: (Mariah)
This paper is not required but is a good complement to Curry et al., and includes a useful visualization of the LGM Atlantic d13C:
This paper is not required but summarizes the current state of the art for the LGM Atlantic d13C:

Week 5 (2/8): Comparing Cd/Ca and d13C
Required Reading: (Pam)
Required Reading: (Andrew)
This paper is not required but summarizes the current state of the art for the LGM Atlantic Cd/Ca:

Week 6 (2/15): Air-sea d13C
Required Reading: (Kate)
Required Reading: (Colin)
This paper is not required but illustrates an early attempt to reconstruct d13Cas for the LGM world ocean:
Also see section 5.2 for a more recent discussion of d13Cas in the LGM Atlantic.

If you are dying to know why aqueous CO2 is isotopically depleted relative to CO2 gas, have a look at . The executive summary derived from a quick skim is as follows: The expectation for heavier isotopologues to be preferentially dissolved in the liquid ("less mobile") phase can be overcome by differences in the van der Vaals attraction between molecules. Since the attraction depends in part on vibration, it is mass dependent. In the case of CO2, 12CO2 has a stronger attraction to H2O than 13CO2 does, so much so that 12CO2 is more soluble in water.

Week 7 (2/22): Deep Pacific
Required Reading: (Katie)
Required Reading: (Caroline)

Week 8 (3/1): Pa/Th kinematic tracer
Required Reading: (Whitney)
Required Reading: (Ursula)

Week 9 (3/8): Constraints from radiocarbon
Required Reading: (Colin)
Required Reading: (Katie)

Week 10 (3/15): Paleo-geostrophy
Required Reading: (Andrew)
Required Reading: (Caroline)

Week 11 (3/22): No Class (Spring Break)

Week 12 (3/29): Numerical models I
Required Reading: (Whitney)

Week 13 (4/5): Numerical models II
Required Reading: (Mariah)
Required Reading: (Kate)

Week 14 (4/12): Southern Ocean dynamics
Required Reading: (Pam)
Required Reading: which also has a . (Mariah)

Week 15 (4/19): Deep sea T/S (the Adkins Blob)
Required Reading: (Whitney)
Required Reading: (Caroline)

Week 16 (4/26): Subtropical gyre circulation and Course Wrap-up
Required Reading: