Abstract

Recent numerical simulations have revealed a possible non-linear interaction between the magnetosphere-plasmasphere and thermosphere-ionosphere sources of mid and low-latitude electrodynamics. As a consequence, quantitative understanding of the sequence of cause-and-effect relationships remains a... Show moreRecent numerical simulations have revealed a possible non-linear interaction between the magnetosphere-plasmasphere and thermosphere-ionosphere sources of mid and low-latitude electrodynamics. As a consequence, quantitative understanding of the sequence of cause-and-effect relationships remains a challenge in spite of increased efforts in observations and modeling. To address this challenge from a global, coupled, system-level perspective, a model that couples inner-magnetosphere, ionosphere, plasmasphere, thermosphere and electrodynamics has been developed. The goal of this approach is to separate out sources of the storm time electric fields between the magnetospheric processes and the neutral wind dynamics, and to evaluate their non-linear interactions. Results from this coupled model suggest that the sources of variability in storm time electric fields are associated with the non-linear interaction between the prompt penetration and disturbance dynamo, such that the response depends on the preconditioning of the coupled system. An appreciation and quantitative evaluation of the variabilities associated with the interaction is vital in interpreting the observations. We also demonstrate that the non-linear interaction has a direct consequence on the response of the ionosphere and thermosphere, with a particular emphasis on the redistribution of plasma observed during super storms. In addition, a couple of unsolved questions still remain with regards to the prompt penetration process itself. We address the unanswered question, concerning the possibility of long-duration penetration, which could be attributed to either an ineffective shielding process or the confusion with the disturbed neutral wind effect. Show less