In order to build useful predictive space weather tools it is necessary to understand the most critical nonlinear dependencies among observed plasma and electromagnetic field variables in the coupled solar wind/magnetosphere system. This project will develop and apply information-theoretical tools such as mutual information, cumulant-based cost, transfer entropy and redundancy as information-dynamical measures of causal dependencies to understand: (1) the underlying dynamical response of the magnetosphere to the solar wind, (2) solar wind-magnetosphere coupling functions, (3) the information horizon and predictability of dynamics in the magnetospheric system, and (4) causal dependencies responsible for the recurrence time of magnetic substorms. This nonparametric, statistical approach assumes no intrinsic underlying dynamics. Information gained from the cumulant-based information flow can be used to guide the development of a variety of space weather tools. As a specific example of the application of the statistical methods, the project will evaluate energetic electron flux at geosynchronous orbit, the stretching of the magnetotail and magnetospheric power flux into the auroral zones. These results will make it possible to estimate a predictability horizon, which will indicate the maximum "look ahead" for which the space weather can be predicted. Information-dynamical measures will also be used to identify causal variables derived from solar wind data that maximize the information content about the magnetospheric response.
The methods and techniques that will be used in this project do not presuppose an underlying dynamics and hence they will work across a wide range of areas in the Sun-Earth system. Detection of the most important nonlinear interactions in the systems will be used to identify the most important causal physical processes and will aid development of physical models and predictive capabilities for understanding severe space weather. The project include training of an undergraduate or beginning graduate student on the basic concepts in nonlinear dynamics with applications to space weather.
