The objective is to identify in 1-second ground-magnetometer data large DB/DT intervals, place them into solar wind and geomagnetic context (storm and substorm correlation) and characterize the…

This federal contract award was granted by the National Aeronautics and Space Administration (NASA) to the Regents of the University of Michigan, Office of Research and Sponsored Projects, doing business as the University of Michigan. The $933,770 grant will fund research to analyze decades of ground-based magnetometer data to identify and characterize rapid changes in the Earth's magnetic field, known as db/dt events. The research aims to better understand the space weather context and drivers of these events, including their association with solar storms and geomagnetic activity. The project will also seek to use a combination of satellite observations and modeling to estimate the optimal spacing of ground-based monitoring stations. This award does not have a set-aside designation. The University of Michigan is a highly regarded public research university with extensive experience conducting federally funded research across a variety of scientific domains.

The objective is to identify in 1-second ground-magnetometer data large DB/DT intervals, place them into solar wind and geomagnetic context (storm and substorm correlation) and characterize the spectral properties of the events at previously under-studied highfrequency (on the order of HZ) signatures. We will analyze decades of magnetometer data from scores of stations. Our recent studies have found: (1) that a significant fraction (40%) of the largest DB/DT events are not associated with substorms and (2) many of the largest DB/DT within the E3/GIC time domain are preceded and/or accompanied by large and more rapid fluctuations (E2). From this list, we will identify events that have both LEO (e.g., swarm, fast) and magnetospheric satellite (e.g., van allen probes, MMS, themis) observations. Though mapping uncertainties and the need to have broad conjunction criteria will make IT difficult to find the same event on the ground and in space, we will characterize the field signatures (e.g., dipolarizations, compressions) and wave properties of the space-based observations to place the events into global context. We will then model select intervals with both models to understand the current and ionospheric electric field structures responsible for the fast and GIC signatures. We will address all three primary objectives ((1) determine the space context of DB/DT, (2) characterize their temporal and spatial scales, and (3) using observations and models estimate the ideal spacing of ground-based observations) of the magnetospheric and ionospheric processes responsible for rapid geomagnetic changes FST.