Thursday 12 Nov 2015: Statistical Science Seminar: Abrupt changes in climate and ecosystems: data-driven approach for identification and characterization
Claudie Beulieu - National Oceanography Centre, Southampton
A growing body of scientific evidence suggests that some elements of the climate system and some ecosystems are experiencing abrupt state changes. These abrupt changes can arise when a small increase in forcing pushes the system across a threshold or they occur as a direct response to a shift in the external forcing (e.g. climate shifts), in both cases leaving the system in a new state after. Additionally, abrupt change can be due to a random reorganization of the system, although the exact mechanism is often unclear. In this talk, I propose a methodology for formal detection of abrupt changes and for distinguishing between forced and unforced (i.e. random) reorganization of the system. For illustration, the methodology is applied to a well-documented marine regime shift in the North Pacific. Finally, opportunities and challenges for the development of change-point detection techniques will be discussed.