Mathematics and Climate Minisymposium, MS106
Friday, July 16
10:30 AM - 12:30 PM
Organizers:
Hans G. Kaper
Argonne National Laboratory and Georgetown University
Mary Lou Zeeman
Bowdoin College
While the issues of climate and climate change are receiving much attention in the public domain, they have received much less attention in the mathematical sciences research community. This is especially surprising since we have only one Earth: the only experiments we can carry out must rely on mathematical models. The speakers in this minisymposium will highlight some of the mathematical problems that have come from climate science and discuss some of the relevant mathematics that are needed to address these problems.
This minisymposium is co-sponsored by the Institute for Mathematics Applied to Geosciences (IMAGe) at NCAR, Boulder, Colorado.
10:30-10:55
Bifurcations, and their Implications, in a Simple Model of Arctic Sea Ice
Mary C. Silber, Northwestern University; Dorian Abbot and Raymond T. Pierrehumbert, University of Chicago
Eisenman and Wettlaufer (PNAS 2009) proposed a simple ODE model for Arctic sea ice subjected to seasonally-varying solar forcing. Weextend their box model to describe both polar and subpolar sea ice, and analyze the dynamics of the coupled system. Subpolar winter sea ice loss is abrupt and causes complete sea ice loss in the polar region as well. Summer sea ice loss does not show threshold behavior and progresses smoothly from south to north.
11:00-11:25
Investigating a Convective Cloud Feedback Mechanism for Warm Climates using Simple and Complex Climate Models
Dorian Abbot, University of Chicago; Eli Tziperman, Harvard University
Complex climate models have difficulty simulating the Arctic climate of ancient warm periods and diverge impressively in their forecast of future sea ice at high CO2. A convective cloud feedback has been proposed that might help resolve these issues. The strength of this feedback and CO2 at which it activates vary widely among the models. Here we use a hierarchy of climate models to investigate the factors that control the activation and strength of this feedback.
11:30-11:55
Multiple Scales in Numerical Models of Ocean Circulation
Robert Higdon, Oregon State University
The circulation of the ocean plays a major role in the global climate system. A fundamental property of this circulation is its very wide ranges of space and time scales. In keeping with the purposes of this minisymposium, this talk will include a general survey of how these ranges of scales can influence modelers' choices of time discretization, vertical coordinate, and physical parameterizations. I will also outline some of my own work on time splitting and time stepping and make some comments about spatial discretizations.
12:00-12:25
Mathematical Issues in Data Assimilation of Data and Models in Climate Research
Juan Restrepo, University of Arizona
Climate data is remarkably sparse and poorly constrained, and models for climate are far from complete. How does one make meaningful forecasts? What are the challenges in this peculiar forecasting framework? What are the tools? I will frame these questions, provide a survey of key ideas, and show some of the work done by my group in nonlinear non-Gaussian data assimilation.