Dipolarizing flux bundles (DFBs) have been suggested to transport energy and momentum from regions of reconnection in the magnetotail to the high latitude ionosphere, where they can generate localized ionospheric currents that can produce large nighttime geomagnetic disturbances (GMDs). In this study we identified DFBs observed in the midnight sector from ~7 to ~10 RE by THEMIS A, D, and E during days in 2015-2017 whose northern hemisphere magnetic footpoints mapped to regions near Hudson Bay, Canada, and have compared them to GMDs observed by ground magnetometers. We found six days during which one or more of these DFBs coincided within ± 3 min with ≥ 6 nT/s GMDs observed by latitudinally closely spaced ground-based magnetometers located near those footpoints. Spherical elementary current systems (SECS) maps and all-sky imager data provided further characterization of two events, showing short-lived localized intense upward currents, auroral intensifications and/or streamers, and vortical perturbations of a westward electrojet. On all but one of these days the coincident DFB – GMD pairs occurred during intervals of high-speed solar wind streams but low values of SYM/H. In some events, in which the DFBs were observed closer to Earth and with lower Earthward velocities, the GMDs occurred slightly earlier than the DFBs, suggesting that braking had begun before the time of the DFB observation. This study is the first to connect spacecraft observations of DFBs in the magnetotail to intense (>6 nT/s) GMDs on the ground, and the results suggest DFBs could be an important driver of GICs.

This paper will report on the effects of an extreme space weather event. On January 20th, 2005, a balloon-borne experiment intended to measure relativistic electron precipitation and its effects was aloft over Antarctica (~32 km; near 70º S, 345º W geographic) throughout the duration of the solar energetic particle (SEP) event. The balloon carried an x-ray scintillation counter, dc electric field, and scalar electrical conductivity sensors. Intense energetic proton precipitation and large increases in the energetic proton population of the outer radiation belts were observed by a global array of observatories and spacecraft. The stratospheric conductivity increased by nearly a factor of 20 above ambient at the time of the SEP event onset and returned to within a factor of two above normal levels within 17 hours. The electric field decreased to near zero following the increase in particle flux at SEP onset. Combined with an atmospheric electric field mapping model, these data are consistent with a shorting out of the global electric circuit and point toward substantial ionospheric convection modifications. It is shown that the conductivity profile predicted by the Sodankylä Ion and Neutral Chemistry (SIC) model does not shield the balloon payload at 32 km from the ionospheric horizontal field. Thus, the data really do indicate a very low level of ionospheric convection over the balloon during the 6 hours following the SEP event. We have used global magnetometer and satellite data to interpret the changes in the vertical field as indicators of large scale convection changes.

The Solar Dynamics Observatory (SDO) is a solar mission in an inclined geosynchronous orbit. Since commissioning, images acquired by Atmospheric Imaging Assembly (AIA) instrument on-board the SDO have frequently displayed “spikes”, pixel regions yielding extreme number of digital counts. These are theorized to occur from energetic electron collisions with the instrument detector system. These spikes are regularly removed from AIA Level 1.0 images to produce clean and reliable data. A study of historical data has found over 100 trillion spikes in the past decade. This project correlates spike detection frequency with radiation environment parameters in order to generate an augmented data product from SDO. We conduct a correlation study between SDO/AIA data and radiation belt activity within the SDO’s orbit. By extracting radiation “spike” data from the SDO/AIA images, we produce a comprehensive data product which is correlated not only with geomagnetic parameters such as Kp, Ap and Sym-H but also with the electron and proton fluxes measured by the GOES-14 satellite. As a result, we find that AIA spikes are highly correlated with the GOES-14 electrons detected by the MAGED and EPEAD instruments at the equator (where the two satellites meet) with Spearman’s Correlation values of ρ=0.73 and ρ=0.53 respectively, while a weaker correlation of ρ=0.47 is shown with MAGPD protons for the two year period where both missions returned data uninterruptedly. This correlation proves that the SDO spike data can be proven useful for characterizing the Van Allen radiation belt, especially at areas where other satellites cannot.