The Carrington storm of September 1859 is one of the largest known geomagnetic storms in the historic record. Two observatories in London were operating at the time and by good fortune both recorded the extreme geomagnetic storm on paper records. These are held at the British Geological Survey and have been made available online as digital images. The next step is to digitally trace over the magnetograms to produce useful digital values. However, scaling the values of digital pixels to International System of Units (SI units) of degrees of angle and nanoTesla is not easy as the original scaling factors are not available. We use a mixture of written reports at the time and notes from the observatory yearbooks to track down plausible scaling factors and to explain the process of digitization of very old records. The data for 10 days covering 25 August to 5 September 1859 are now available for other researchers to use.

The polar cap (PC) indices are geomagnetic activity indices derived from magnetic variations measured in the central northern and southern polar caps and scaled with solar wind parameters. They quantify the coupling between the solar wind and the magnetosphere providing power to space weather disturbances such as strong electric currents in the polar ionosphere. These currents may in turn generate upper atmosphere heating which may disturb satellite orbits and induce electric currents and voltages in conducting structures at ground level. During the strong events the geomagnetically induced currents can cause power line failures in important subauroral power grids. The geomagnetic disturbance level is conveniently monitored through the PC indices. However, due to the harsh Arctic and Antarctic environments, measurements or transmissions of magnetic data may be impeded. Thus, alternative PC index sources are needed to ensure reliable space weather monitoring. The present work defines and describes an alternative PCS (South) index based on measurements from the Antarctic Dome Concordia observatory to supplement the standard PCS index based on data from Vostok observatory.

Space particle radiation is one of the main concerns in planning long-term human space missions. There are two main types of hazardous particle radiation: (a) solar energetic particles (SEP) originating from the Sun and (b) galactic cosmic rays (GCR) that come from the distant galaxies in space. Fluxes in particles of solar origin maximize during solar maximum when particles originating from the distant galaxies are more efficiently deflected from the solar system during times when the sun is active. Our calculations clearly demonstrate that the best time for launching a human space flight to Mars is during the solar maximum, as it is possible to shield from SEP particles. Our simulations show that an increase in shielding creates an increase in secondary radiation produced by the most energetic GCR, which results in a higher dose, introducing a limit to a mission duration. We estimate that a potential mission to Mars should not exceed approximately 4 years. This study shows that while space radiation imposes strict limitations and presents technological difficulties for the human mission to Mars, such a mission is still viable.

Geomagnetically induced currents (GICs) result due to the interaction of the solar wind with Earth's magnetosphere, and are catastrophic to our technologically dependent society. Since GIC data is proprietary, the time variability of geomagnetic perturbation is used as a proxy, and forecasting these perturbation at high spatial resolution and time cadence is important. In this work we develop a deep learning-based model to forecast these perturbation measurements at arbitrary spatial resolutions and at high time cadence, using only the solar wind measurements. Our model outperforms, or has consistent performance at worse with benchmark models, and hence can provide quick, accurate forecasts at high time cadence across the whole globe.

On 24 March 1940, a pair of concentrated, and possibly interacting, bursts of solar wind forced an intense magnetic storm on Earth. Geomagnetic field variation during the storm induced high-amplitude geoelectric fields in the solid Earth's conducting interior. These geoelectric fields drove uncontrolled currents in grounded long-wire communication- and electricity-power-transmission systems in the United States and Canada, causing significant operational interference in those systems. This interference was primarily experienced in the upper Midwest and the eastern United States, and many incidents of interference were reported in the popular press. Voltages monitored on several lines were greater than studies estimate would have occurred during the great storm of March 1989. In terms of its impact on communication and power systems, the March 1940 magnetic storm was one of the most significant ever experienced by the United States. Modern communication systems are less dependent on long electrically conducting transmission lines. On the other hand, modern electric-power-transmission systems are more dependent on such lines, and they, thus, might experience interference with the future occurrence of a storm like that of March 1940.

SpaceX Starlink lost 38 of 49 satellites after the launch of Group 4-7 in February 2022 due to enhanced neutral density associated with a geomagnetic storm. Based on observations, forecasts, and numerical simulations from the National Oceanic and Atmospheric Administration Space Weather Prediction Center (SWPC), this study provides a detailed analysis of the space weather conditions and neutral density environment during the event. Simulation results suggest that during this minor to moderate geomagnetic storm, the neutral density enhancement was about 50%–125% increase at altitudes ranging between 200 and 400 km. The operational coupled Whole Atmosphere Model and Ionosphere Plasmasphere Electrodynamics physics-based model demonstrates better performance compared to empirical thermospheric neutral density models, one of which was used by the Starlink team. With an increasing number of satellites in low-Earth orbit, it becomes crucial for SWPC to establish suitable alerts and warnings based on neutral density predictions to provide users guidance for preventing satellite losses due to drag and to aid in collision avoidance calculations.

On 03 February 2022, SpaceX launched 49 Starlink satellites into staging orbits at 210 km above sea level prior to raising them to their operational altitudes of 550 km. The pre-launch space weather briefing included no information about an ongoing geomagnetic storm. Excessive atmospheric drag due to the geomagnetic storm resulted in 38 of the satellites re-entering the atmosphere on or about 07 February 2022. We use both models and direct measurements of the atmospheric density during the event to show that density values were enhanced by 20%–30% at the 210 km staging altitude relative to values prior to the geomagnetic storm onset, while they were enhanced 90%–160% at higher altitudes. We recommend improving our ability to model the upper atmospheric response to geomagnetic storms to provide accurate forecasts and actionable “nowcasts” of conditions in low Earth orbit to launch controllers, space traffic managers, and satellite operators.