Is the storm time response of the inner magnetospheric hot ions universally similar or driver dependent?

摘要

The Hot Electron and Ion Drift Integrator (HEIDI) model was used to simulate all of the intense storms (Dst _(min) <-100 nT) from solar cycle 23 (1996-2005). These storms were classified according to their heliospheric driving structure, namely, either an interplanetary coronal mass ejection (ICME) or a corotating interaction region and its trailing high-speed stream (CIR/HSS). Five different HEIDI input combinations were used to create a large collection of numerical results, varying the plasma outer boundary condition and electric field description in the model. Statistical data-model analyses were conducted on the total energy content, yielding error estimates on the correlation coefficients and root-mean-square error values for each run set. The accuracy of each run set depends on the method of comparison and classification of the driver. For the correlation coefficients, the simulations using a local-time-dependent outer boundary condition were consistently better than those using a local-time-averaged (but high-time-resolution) nightside boundary condition, with the simplistic electric field being better than the self-consistent field description. For the root-mean-square error, the results are less conclusive. For the CIR/HSS-driven storms, those with the high-time-resolution boundary condition were systematically better than those with the local-time-dependent (but lower-time-resolution) boundary condition. For the ICME-driven storms, those run sets employing the self-consistent electric field calculation were systematically better than those using the simplistic electric field. The implication, therefore, is that the inner magnetospheric physical response to strong driving is, at least to some degree, fundamentally different depending on the heliospheric structure impacting geospace. Specifically, for an accurate SYMH* comparison, it is found that CIR/HSS events respond strongly to transient spikes in the plasma outer boundary condition, while ICME passages exhibit a more highly structured electric field.