MCRN Colloquium Webinar begins
2015 Fall Schedule
Monday, November 9th, 10:30am EST: Chris Jones (Director of MCRN)
Title: Where’s the Math in Climate Science?
Abstract: Climate science is dominated by the use of large-scale models, of which there are only 30 or so around the world. It might then seem that the need for mathematics is limited to areas that directly support the operation of such models. I will explain, by digging into the way the models work, this is not correct and that climate studies demand the development of various emerging as well as established areas of mathematics. Along the way, I will explain how models are used and what some of the big open issues are to further our understanding of how the climate works. The talk will include discussion of a case study of El Niño based on joint work with Andrew Roberts, Esther Widiasih, Axel Timmerman and John Guckenheimer.
Note: This will be a general and motivational talk that should be accessible, and I hope of interest, to pure and applied mathematicians at all levels from undergrad on up.
(This talk begins at 15:30 GMT = 5:30 HAST = 7:30 PDT = 8:30 MDT = 9:30 CDT = 16:30 CET = 21:00 IST, and on Tuesday, the 10th at 00:30 JST = 2:00 ACDT = 2:30 AEDT = 4:30 NZDT)
Thursday, November 20th, 7:00pm EST: Luke Bennetts (University of Adelaide)
Title: Modelling the marginal ice zone
Abstract: The marginal ice zone (MIZ) is the 10s to 100s of kilometres of partially ice-covered ocean, which sits between the open ocean and the quasi-continuous ice cover. It’s a highly dynamic region, where open ocean wave processes impact the ice cover, and it’s becoming larger and more significant in the era of climate change.
I’ll summarise existing models of the MIZ (with a slight bias for my own work). I’ll then discuss how these models are being integrated into large-scale models used for operational forecasting and climate studies.
(This talk begins on Thursday at 14:00 HAST = 16:00 PST = 17:00 MST = 18:00 CST, Midnight 00:00 GMT between Thursday and Friday, and Friday at 1:00 CET = 5:30 IST = 9:00 JST = 10:30 ACDT = 11:00 AEDT = 13:00 NZDT)
Monday, November 23rd, 10:30am EST: Jonah Bloch-Johnson (University of Chicago, Department of the Geophysical Sciences)
Title: Global warming could be nonlinear
Abstract: It is widely acknowledged that many components of the Earth's climate system exhibit nonlinear behavior when forced, with examples ranging from ice sheets to ocean circulations to savanna. These changes, as profound as they are, are not expected to greatly impact global climate, as characterized by values such as the global mean annual surface temperature. This value is usually assumed, and often modeled, to be roughly proportional to the greenhouse gas-induced radiative forcing. In the limit of large (i.e. greater than anthropogenic) forcing, this approximation is expected to break down dramatically. In this talk, I will use a simple conceptual model to argue that this threshold might be closer than one might expect. I will demonstrate how the effect of a temperature-dependent sensitivity can be confused with model error, creating selection bias, with examples drawn from preliminary results of a perturbed physics enesmble. I will also show the importance of this effect for determining the risk of high warming. I will discuss evidence from paleoclimate that can help constrain this temperature dependence. Finally, I will briefly discuss how regional patterns of feedbacks can complicate attempts to diagnose nonlinear sensitivity.
Thursday, December 3rd, 7:00pm EST: Rachel Kuske (University of British Columbia)
Title: New averaging results motivated by climate models: fat tails, oscillations, and tipping
Abstract: We review recent results where new averaging approaches are developed and applied in the context of systems with multiple time scales and fat tails and in non-autonomous multiple scale systems with oscillatory forcing. These types of systems appear in a variety of higher dimensional climate models, as well as in other areas of application. The results open new research directions, with potential to better address questions like: which mechanisms contribute to fat-tail statistical properties appearing in climate data? What are reasonable approximations for multiple scale systems with non-Gaussian behaviour? How can these approximations provide insight into the dynamics of larger models, such as parameter ranges with large variability, tipping, or reversibility? Some areas for further research are discussed.
Joint work with: Thomas Erneux, Adam Monahan, Will Thompson, and Jielin Zhu
* For more information, see the latest MCRN Newsletter.
Friday, January 15th, 2016, 9:30am EST: Henk Dijkstra (University of Utrecht, Holland)