Alfven waves have been discovered in many astronomical plasmas, such as the Sun and other planets of the solar system. These are magnetohydrodynamic waves that carry energy inside the magnetosphere and energize particles. They are crucial in understanding the boundary between the magnetosphere and ionosphere and in producing the aurora. This project is a detailed study of this process which is important for predicting and preparing for space weather effects. Graduate students will also be supported in research.
This project studies the role of kinetic Alfven waves (KAW) in magnetosphere-ionosphere coupling. The work will focus on a statistical, observational study of multi-year satellite data using superposed epoch analysis, substorm onset lists, and geomagnetic indices for relating the observations to specific geomagnetic conditions. The goals are to answer the following: (1) What is the global spatial distribution and total power of KAW above the auroral acceleration region (AAR) under various geomagnetic conditions (AE index, substorm, storm)? (2) What is the temporal evolution of the global distribution and total power of KAW during different phases of substorms and storms and as a function of time? (3) What is the contribution of KAW to the Alfven wave budget (including MHD regime)? (4) What is their significance in the M-I coupling above the AAR in relation to Alfvenic observations below the AAR and from the generator region?
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
