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PyIRI: Whole‐Globe Approach to the International Reference Ionosphere Modeling Implemented in Python

  •  5 April 2024

Key Points

  • Python tool for rapid global ionospheric electron density estimates

  • Novel approach to running the core of the International Reference Ionosphere model

  • 24-hr global electron density in a few seconds

Open access

Modeling Geomagnetically Induced Currents in the Alberta Power Network: Comparison and Validation Using Hall Probe Measurements During a Magnetic Storm

  •  5 April 2024

Key Points

  • Unexpectedly large neutral-to-ground currents up to 117 A were measured at substations during 24 April 2023 geomagnetic storm

  • Geomagnetically induced current (GIC) model has correlation coefficients with GIC measurements between 0.46 and 0.79 at five substations, although peak values underestimated

  • Largest modeled currents are concentrated in northeastern Alberta and Edmonton region, not necessarily only on highest voltage network

Open access

A Comparison of Auroral Oval Proxies With the Boundaries of the Auroral Electrojets

  •  4 April 2024

Key Points

  • We present a new electrojet boundary data set and compare it with auroral oval proxies

  • On average proton aurora boundaries are more aligned with electrojet boundaries than electron aurora boundaries

  • Noon and midnight electrojet discontinuities present a problem for auroral oval determination from electrojet boundaries

Open access

Assimilating Space‐Based Thermospheric Neutral Density (TND) Data Into the TIE‐GCM Coupled Model During Periods With Low and High Solar Activity

  •  31 March 2024

Key Points

  • Investigating the impact of covariance localization on the assimilation of Thermospheric Neutral Density data into TIE-GCM

  • Assimilation the of TND data into TIE-GCM considerably improves the electron density forecasts in the ionosphere

  • The agreement of the predicted TND and electron profiles with observations is better during the period of low solar than the high solar

Open access

Accuracy of Global Geospace Simulations: Influence of Solar Wind Monitor Location and Solar Wind Driving

  •  29 March 2024

Key Points

  • Solar wind monitor distance from Sun-Earth line impacts the sign of SYM-H median errors where it overpredicts (−4.16 nT) for distances <20 RE

  • Standard deviation of SYM-H error increases with solar wind driving intensity (19–28 nT), but is less dependent on phase front normal

  • Regression coefficients show a dependence of the SYM-H error standard deviations on the phase front normal (0.123) and on pressure (0.293)

Open access

Geoelectric Field Estimations During Geomagnetic Storm in North China From SinoProbe Magnetotelluric Impedances

  •  28 March 2024

Key Points

  • The geoelectric field and induced voltage distribution during storm in North China were estimated using MT impedances

  • High-amplitude geoelectric fields were mainly distributed in the high-resistivity Taihang-Lvliang, Yanshan, and Luxi orogenic belts

  • Vulnerable transmission lines were concentrated in the central part of North China

free access

Issue Information

  •  25 March 2024
Open access

Thank You to Our Peer Reviewers in 2023

  •  25 March 2024

Key Points

  • The editors thank the 2023 peer reviewers

Open access

Geomagnetic Disturbances Due To Neutral‐Wind‐Driven Ionospheric Currents

  •  23 March 2024

Key Points

  • Neutral-wind-driven currents contribute to about 10%–30% of the total geomagnetic disturbances (GMDs) at locations where the high-latitude electric potential is dominant

  • During the storm recovery phase, neutral-wind-driven currents are the primary sources for middle-latitude GMDs on the dayside

  • At middle latitudes, the magnitude of recovery-time neutral-wind-driven GMDs is comparable to that caused by ring currents

Open access

Ionospheric TEC Prediction Based on Ensemble Learning Models

  •  20 March 2024

Key Points

  • Three ensemble learning models are employed to predict total electron content (TEC) in various latitudes using data spanning a solar cycle

  • eXtreme Gradient Boosting model has less predicted errors than Gradient Boosting Decision Tree and Decision Tree models, and the previous TEC history dominants the predicted TEC values

  • The RMSE increases with the predicted time advance, and the average relative error is the minimum in the mid-latitude

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free access

International Reference Ionosphere 2016: From ionospheric climate to real‐time weather predictions

Key Points

  • New models for the F2 peak height hmF2 in IRI-2016
  • Development of the Real-Time International Reference Ionosphere (IRI)
  • Improved description of IRI ion composition at low and high solar activities

free access

The 10.7 cm solar radio flux (F10.7)

Key Points

  • To provide a source point for user information about the 10.cm solar radio flux
  • How it's measured and how accurate it is
  • Cautionary information about how it should be used

free access

The Challenge of Machine Learning in Space Weather: Nowcasting and Forecasting

Key Points

  • Machine learning (ML) has enabled advances in industrial applications; space weather researchers are adopting and adapting ML techniques
  • This introduction to machine learning concepts is tailored for the Space Weather community, but applicable to many other communities
  • This introduction describes forecasting opportunities in a gray-box paradigm that combines physics-based and machine learning approaches

Open access

The Geomagnetic Kp Index and Derived Indices of Geomagnetic Activity

Key Points

  • Production and distribution of nowcast and definitive Kp index and derived products

  • Kp is estimated to have decreased from 1932 to 2020 by one third of a unit due to geomagnetic secular variation

  • Improved agreement between nowcast and definitive Kp since August 2020

free access

Measures of Model Performance Based On the Log Accuracy Ratio

Key Points

  • The median symmetric accuracy and symmetric signed percentage bias are introduced to address some drawbacks of current metrics
  • The spread of a multiplicative linear model can be robustly estimated using the log accuracy ratio
  • The properties of the median symmetric accuracy and the symmetric signed percentage bias are demonstrated on radiation belt examples

Open access

Forecasting Global Ionospheric TEC Using Deep Learning Approach

Key Points

  • The LSTM neural network is adopted to predict the global ionosphere TEC
  • The use of the external solar EUV flux and Dst index is able to improve the prediction performance of the spherical harmonic (SH) coefficients
  • The developed LSTM model performs well during both quiet and storm conditions

free access

A 21st Century View of the March 1989 Magnetic Storm

Key Points

  • The extreme space weather conditions in March 1989 were the result of successive CMEs
  • A secondary CME (resulting from a less intense flare) was the “trigger” for the extreme event
  • The Hydro-Québec system collapse occurred well before Dst reached its extreme value

free access

Geomagnetically induced currents: Science, engineering, and applications readiness

Key Points

  • We provide a broad overview of the status of the GIC field
  • We utilize the Applications Readiness Levels (ARL) concept to quantify the maturity of our GIC-related modeling and applications
  • This paper is the high-level report of the NASA Living With a Star GIC Working Group findings

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Open access

The Polar Cap (PC) Index: PCS Version Based on Dome‐C Data

Key Points

  • Polar cap (PC) index of unsurpassed relevance based on new Antarctic observatory

  • Consistent definition and description of PC index derivation processes

  • Disclosure of invalid PCS (South) index series

Plain Language Summary

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.

Open access

The Geomagnetic Kp Index and Derived Indices of Geomagnetic Activity

Key Points

  • Production and distribution of nowcast and definitive Kp index and derived products

  • Kp is estimated to have decreased from 1932 to 2020 by one third of a unit due to geomagnetic secular variation

  • Improved agreement between nowcast and definitive Kp since August 2020

free access

A 21st Century View of the March 1989 Magnetic Storm

Key Points

  • The extreme space weather conditions in March 1989 were the result of successive CMEs
  • A secondary CME (resulting from a less intense flare) was the “trigger” for the extreme event
  • The Hydro-Québec system collapse occurred well before Dst reached its extreme value

Open access

Beating 1 Sievert: Optimal Radiation Shielding of Astronauts on a Mission to Mars

Key Points

  • Space missions to Mars should be scheduled to be launched during solar max

  • Optimal spacecraft shielding is ~30 g/cm2, which allows long-duration flights of ~4 years

  • Increase of shielding thickness beyond ~30 g/cm2 results in dose increase

Plain Language Summary

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.

Open access

Global Geomagnetic Perturbation Forecasting Using Deep Learning

Key Points

  • Global high-time cadence models for forecasting geomagnetic perturbations are necessary for this technologically driven society

  • We develop a grid-free model that forecasts these perturbations 30 min in the future at any spatial resolution at 1 min cadence

  • The proposed model outperforms/has consistent performance against the state of the practice local (global) high (low) time cadence models

Plain Language Summary

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.

Open access

The March 1940 Superstorm: Geoelectromagnetic Hazards and Impacts on American Communication and Power Systems

Key Points

  • Extreme geomagnetic field variation realized during the March 1940 storm might have resulted from the interaction of ICMEs

  • Long-line interference in the U.S. occurred during local daytime and in the upper Midwest and East, where surface impedance is high

  • Voltages measured on grounded long lines during the storm exceeded 1-min voltages that would have been induced by the March 1989 storm

Plain Language Summary

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.

Open access

Space Weather Environment During the SpaceX Starlink Satellite Loss in February 2022

Key Points

  • Geomagnetic storms lead to thermosphere expansion and increase satellite drag

  • National Oceanic and Atmospheric Administration's coupled Whole Atmosphere Model and Ionosphere Plasmasphere Electrodynamics, a physics-based model, captures the enhanced neutral density environment responsible for the Starlink satellite loss event

  • Alerts and warnings based on neutral density predictions during geomagnetic storms are critical for satellite drag estimation

Plain Language Summary

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.

Open access

The Thermosphere Is a Drag: The 2022 Starlink Incident and the Threat of Geomagnetic Storms to Low Earth Orbit Space Operations

Key Points

  • Geomagnetic storms can cause large variations in neutral density and satellite drag, especially at Very Low Earth Orbit altitudes

  • Data assimilative empirical model results and observations during the Starlink event show 20%–30% neutral density enhancements at 210 km

  • Full-physics data assimilative models and real-time measurements of thermospheric conditions can mitigate impacts on low Earth orbit operations

Plain Language Summary

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.

free access

The 10.7 cm solar radio flux (F10.7)

Key Points

  • To provide a source point for user information about the 10.cm solar radio flux
  • How it's measured and how accurate it is
  • Cautionary information about how it should be used

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