A comprehensive statistical study of magnetospheric sawtooth events during solar cycle 24 (2008–2016). We compile an 81-event catalog from geostationary energetic particle detectors and characterize their solar-cycle distribution, intertooth periodicity, and multi-point injection and dipolarization signatures. Results show near-simultaneous particle injections across all magnetic local time sectors, while magnetic field dipolarization is confined to the midnight region. This rules out global magnetospheric instability as the driver and points instead to nightside tail reconnection with enhanced convection.

A side-by-side comparison of magnetospheric substorms and sawtooth events using multi-point observations from THEMIS, RBSP, and geostationary satellites. Despite distinct solar wind driving conditions, both phenomena exhibit similar magnetic field dipolarization signatures at 8–10 R_E. Sawtooth events occur during sustained southward IMF and elevated proton densities; both show a roughly three-hour periodicity, but periodicity alone does not create the sawtooth mode. The results indicate that sawtooth events represent a storm-time mode of repetitive substorm activity driven by sustained energy input.

We present MIDL, a solar wind data product that merges observations from ACE, DSCOVR, and Wind via a three-stage process: per-satellite filtering and despiking, multi-satellite quality screening with agreement-first source selection, and propagation to the bow shock nose using both ballistic and 1D MHD methods. MIDL achieves near-complete temporal coverage (>95%) with strong agreement against OMNI (Pearson r = 0.99 for V_x, 0.96 for density, 0.86 for B_z). The product is publicly available through a web interface and Python package.

Using SWMF Geospace simulations driven by observed solar wind for 122 storm periods (2010–2019), we investigate whether the intrinsic periodicity of the magnetospheric loading-unloading cycle is reproduced in global MHD. Simulations reproduce a 2–4 hour loading-unloading periodicity with a spectral peak near 144 minutes, consistent with observations, but fail to reproduce sawtooth event morphology with global particle injections. This suggests that the periodicity is a fundamental property of the coupled system, while the injection mechanism requires physics beyond ideal MHD.

Extending the MSWIM2D solar wind model into a forecast tool for the outer heliosphere. Using a persistence-based prediction tier driven by the most recent observed solar wind, we assess how far ahead and how far out the model retains skill, quantifying forecast accuracy as a function of heliocentric distance and lead time for the planets and deep-space spacecraft.