Research

Research projects within the USGS Geomagnetism Program are targeted for societal relevance, especially for space-weather hazard science. Consistent with the goals and issues addressed in the USGS Natural Hazards Strategic Plan, these research projects support pursuit of fundamental understanding of geomagnetic storms and related phenomena, development of geomagnetic products needed for assessments and real-time situational awareness, informed operation of the Program's magnetic-observatory network. Geomagnetism Program research staff provide outside advice, national and international leadership, and write educational articles about geomagnetic and space-weather hazards.

Fundamental research within the USGS Geomagnetism Program is concentrated on the analysis of the information content of magnetic-field time series acquired at ground-base magnetic observatories. Methods include formal time-series and statistical analysis, and data assimilation for physics-based models of the magnetosphere and ionosphere. Recent work has included the analysis of the symmetry (and asymmetry) of low-latitude ground-level magnetic disturbance during individual magnetic storms; long-term secular change in geomagnetic disturbance and its correlational relationship with sunspots and interplanetary solar wind; secular change in geomagnetic activity and global climate change; solar-quiet geomagnetic variation and periodic geomagnetic tides; extreme-geophysical-event analysis; and investigation of claims that earthquakes are sometimes preceded by magnetic precursory signals.

Guided by fundamental understanding, geomagnetic products are developed to meet the needs of the space-weather community for hazard assessments and real-time situational awareness. Recent work has concentrated on the development of new and improved summary-index measures of global magnetic disturbance related to the magnetospheric ring current and the auroral electrojet, needed for validating and as input for physics-based models of the space environment; and localized measures of magnetic disturbance and geomagnetically-induced currents needed by the electric power-grid industry. The Geomagnetism Program recently initiated a project for estimating geomagnetically-induced currents in the lithosphere in order to assess and mitigate hazards for the power-grid industry.