Geospace Science Research Articles

‘Space Weather Sentinels’: Halley and the evolution of geospace science

The words ‘Antarctic science’ are often synonymous with dramatic, sublime images of penguins and frozen landscapes, but not all Antarctic science looks to the ice or its megafauna. While Antarctica is an important focus of scientific research in its own right, it is also a platform ideally suited to the pursuit of geophysical science—such as solar–terrestrial physics. Investigating the histories of these fields of science contributes not only to our understanding of the history of Antarctic science, but also to the evolution of Antarctic research stations as sites entangled in international networks of people and places beyond Earth's coldest continent. This paper presents the case of Halley VI research station, a British Antarctic Survey station on the Brunt Ice Shelf in East Antarctica, and its co-evolution with geospace science throughout the 1970s and 1980s. Halley's infrastructure and science shaped, and were shaped by, the evolution of geospace science in this period, via Halley's involvement in a series of international geospace collaborations. This co-evolution also affected how the British Antarctic Survey was able to respond to changing UK science policies in later decades. This case demonstrates that Antarctic stations, while physically remote, have historically been entangled in complex networks of people, politics and science that range far beyond Antarctica itself.

Data infrastructure needs for ground-based geospace science

Data infrastructure needs for ground-based geospace science

Faculty Development in geoSpace Science (NSF)

Faculty Development in geoSpace Science (NSF)

Pathways into the Earth, Ocean, Polar, and Atmospheric and Geospace Sciences (NSF)

Pathways into the Earth, Ocean, Polar, and Atmospheric and Geospace Sciences (NSF)

Neutral winds from mesosphere to thermosphere—past, present, and future outlook

The Earth’s upper atmosphere (85–550 km) is the nearest region of geospace and is highly dynamic in nature. Neutral winds impact a large portion of the dynamics in this region. They play a critical role in determining the state of the ionosphere-thermosphere system at almost all latitudes and altitudes. Their influences range from wave breaking/dissipation in the mesosphere and lower thermosphere to global redistribution of energy and momentum deposited at high latitudes by the magnetosphere. Despite their known importance, global geospace neutral winds have remained one of the least sampled state parameters of the Earth’s upper atmosphere and are still poorly characterized even after multiple decades of observations. This paper presents an overview of historical neutral wind measurements and the critical need for their global height-resolved measurements. Some satellite missions are still operational and deliver valuable information on the contribution of neutral winds in global atmospheric dynamics. However, many significant gaps remain in their global monitoring, and our current understanding of the drivers of neutral winds is incomplete. We discuss the challenges posed by these measurement gaps in understanding geospace physics and weather. Further, we propose some wind observation solutions, including the simultaneous operations of upcoming NASA DYNAMIC and GDC missions as well as support for the development of ground-based observing methodologies, that will lead to fundamental advances in geospace science and address humanity’s emerging space needs.

Atmospheric and Geospace Sciences Postdoctoral Research Fellowships (NSF)

Atmospheric and Geospace Sciences Postdoctoral Research Fellowships (NSF)

Education Programs in Atmospheric and Geospace Sciences (NSF)

Education Programs in Atmospheric and Geospace Sciences (NSF)

Nonlinear Least Squares Fitting Technique for the Determination of Field Line Resonance Frequency in Ground Magnetometer Data: Application to Remote Sensing of Plasmaspheric Mass Density

AbstractThe accurate determination of the field line resonance (FLR) frequency of a resonating geomagnetic field line is necessary to remotely monitor the plasmaspheric mass density during geomagnetic storms and quiet times alike. Under certain assumptions the plasmaspheric mass density at the equator is inversely proportional to the square of the FLR frequency. The most common techniques to determine the FLR frequency from ground magnetometer measurements are the amplitude ratio (AR) and phase difference (PD) techniques, both based on geomagnetic field observations at two latitudinally separated ground stations along the same magnetic meridian. Previously developed automated techniques have used statistical methods to pinpoint the FLR frequency using the AR and PD calculations. We now introduce a physics‐based automated technique, using nonlinear least squares fitting of the ground magnetometer data to the analytical resonant wave equations, that reproduces the wave characteristics on the ground, and from those determine the FLR frequency. One of the advantages of the new technique is the estimation of physics‐based errors of the FLR frequency, and as a result of the equatorial plasmaspheric mass density. We present analytical results of the new technique, and test it using data from the Inner‐Magnetospheric Array for Geospace Science ground magnetometer chain along the coast of Chile and the east coast of the United States. We compare the results with the results of previously published statistical automated techniques.

Reproducible Software Environment: a tool enabling computational reproducibility in geospace sciences and facilitating collaboration

The Reproducible Software Environment (Resen) is an open-source software tool enabling computationally reproducible scientific results in the geospace science community. Resen was developed as part of a larger project called the Integrated Geoscience Observatory (InGeO), which aims to help geospace researchers bring together diverse datasets from disparate instruments and data repositories, with software tools contributed by instrument providers and community members. The main goals of InGeO are to remove barriers in accessing, processing, and visualizing geospatially resolved data from multiple sources using methodologies and tools that are reproducible. The architecture of Resen combines two mainstream open source software tools, Docker and JupyterHub, to produce a software environment that not only facilitates computationally reproducible research results, but also facilitates effective collaboration among researchers. In this technical paper, we discuss some challenges for performing reproducible science and a potential solution via Resen, which is demonstrated using a case study of a geospace event. Finally we discuss how the usage of mainstream, open-source technologies seems to provide a sustainable path towards enabling reproducible science compared to proprietary and closed-source software.

Pathways into the earth, ocean, polar, and atmospheric and geospace sciences (NSF)

Federal Grants & ContractsVolume 44, Issue 1 p. 3-3 Grant Alerts Pathways into the earth, ocean, polar, and atmospheric and geospace sciences (NSF) First published: 03 December 2019 https://doi.org/10.1002/fgc.30780Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume44, Issue15 December 2019Pages 3-3 RelatedInformation

Ushering in a New Frontier in Geospace Through Data Science

AbstractOur understanding and specification of solar‐terrestrial interactions benefit from taking advantage of comprehensive data‐intensive approaches. These data‐driven methods are taking on new importance in light of the shifting data landscape of the geospace system, which extends from the near Earth space environment, through the magnetosphere and interplanetary space, to the Sun. The space physics community faces both an exciting opportunity and an important imperative to create a new frontier built at the intersection of traditional approaches and state‐of‐the‐art data‐driven sciences and technologies. This brief commentary addresses the current paradigm of geospace science and the emerging need for data science innovation, discusses the meaning of data science in the context of geospace, and highlights community efforts to respond to the changing landscape.

The Future of Ground Magnetometer Arrays in Support of Space Weather Monitoring and Research

AbstractA community workshop was held in Greenbelt, Maryland, on 5–6 May 2016 to discuss recommendations for the future of ground magnetometer array research in space physics. The community reviewed findings contained in the 2016 Geospace Portfolio Review of the Geospace Section of the Division of Atmospheric and Geospace Science of the National Science Foundation and discussed the present state of ground magnetometer arrays and possible pathways for a more optimal, robust, and effective organization and scientific use of these ground arrays. This paper summarizes the report of that workshop to the National Science Foundation (Engebretson & Zesta, ) as well as conclusions from two follow‐up meetings. It describes the current state of U.S.‐funded ground magnetometer arrays and summarizes community recommendations for changes in both organizational and funding structures. It also outlines a variety of new and/or augmented regional and global data products and visualizations that can be facilitated by increased collaboration among arrays. Such products will enhance the value of ground‐based magnetometer data to the community's effort for understanding of Earth's space environment and space weather effects.

A 20-Year History of NSF-Supported Atmospheric Science Field Campaigns: Statistics and Demographics

Abstract Over the past two decades, the National Science Foundation’s Division of Atmospheric and Geospace Sciences (AGS) has funded nearly 200 atmospheric science–related field campaigns that have included deployment of AGS-sponsored observing facilities. These projects have spanned the range from modest, single-investigator experiments to massive, multi-investigator, multiagency campaigns. They have occurred both domestically and abroad, on every continent and over most oceans. In this article, we present an analysis of some of the details about these campaigns, including such elements as deployment location and cost of the campaign, and of statistics related to the principal investigators (e.g., type and location of institution, gender, years since degree). In addition, we assess trends in field campaign cost. These results provide a retrospective view of atmospheric science field work that has been supported since 1992.

The Unifying Principle of Coordinated Measurements in Geospace Science

AbstractSpace scientists recognize geospace as a coupled dynamical system extending from the Earth's upper atmosphere, ionosphere, and magnetosphere, through interplanetary space to the Sun. The weather in geospace describes variability in the electromagnetic fields, particle radiation, plasmas, and gases permeating it, usually in response to solar disturbances. Severe space weather poses a significant threat to human activities in space and to modern technological systems deployed both in space and at Earth. The challenge of characterizing and predicting space weather requires widely distributed, coordinated observations. Partnerships among government agencies, international consortia, and the private sector are developing creative solutions to address this challenge. This brief commentary highlights some of the coordinated measurements and data systems that are unifying knowledge of the geospace environment.

Low-Dimensional Structure Vacuum-Ultraviolet-Sensitive (λ < 200 nm) Photodetector with Fast-Response Speed Based on High-Quality AlN Micro/Nanowire.

A low-dimensional-structure vacuum-ultraviolet-sensitive photodetector based on high-quality aluminum nitride (AlN) micro-/nanowires is reported. This work, for the first time, demonstrates that a semiconductor nanostructure can be applied in vacuum-ultraviolet (VUV) photon detection and opens a way for developing diminutive, power-saving, and low-cost VUV materials and sensors that can be potentially applied in geospace sciences and solar-terrestrial physics.

CONSTRAINING SOLAR FLARE DIFFERENTIAL EMISSION MEASURES WITH EVE AND RHESSI

Deriving a well-constrained differential emission measure (DEM) distribution for solar flares has historically been difficult, primarily because no single instrument is sensitive to the full range of coronal temperatures observed in flares, from $\lesssim$2 to $\gtrsim$50 MK. We present a new technique, combining extreme ultraviolet (EUV) spectra from the EUV Variability Experiment (EVE) onboard the Solar Dynamics Observatory with X-ray spectra from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), to derive, for the first time, a self-consistent, well-constrained DEM for jointly-observed solar flares. EVE is sensitive to ~2-25 MK thermal plasma emission, and RHESSI to $\gtrsim$10 MK; together, the two instruments cover the full range of flare coronal plasma temperatures. We have validated the new technique on artificial test data, and apply it to two X-class flares from solar cycle 24 to determine the flare DEM and its temporal evolution; the constraints on the thermal emission derived from the EVE data also constrain the low-energy cutoff of the non-thermal electrons, a crucial parameter for flare energetics. The DEM analysis can also be used to predict the soft X-ray flux in the poorly-observed ~0.4-5 nm range, with important applications for geospace science.

Comparison of magnetic perturbation data from LEO satellite constellations: Statistics of DMSP and AMPERE

AbstractDuring the past decade engineering‐grade magnetic field measurements from the low Earth orbiting (LEO) Iridium constellation of communication satellites have been available to the geospace science community as a tool to map field‐aligned currents. The Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) applied to Iridium measurements markedly improved the temporal and spatial resolution of these data. We developed new methods to compare data from the latest improvement to AMPERE with those from a constellation of four LEO Defense Meteorological Satellite Program (DMSP) spacecraft that carry high‐resolution magnetometers. To perform the comparisons, we transformed all data to a common coordinate frame and altitude (110 km) and developed a means of computing spacecraft magnetic conjunctions. These conjunctions yield discrepancies in the magnetic field perturbations measured at each proximate spacecraft. During the geomagnetic disturbance of 29–30 May 2010, the vector differences in the horizontal perturbations at closest approach (typically a few tens of kilometers) had mean, median, and standard deviation values of 132 nT, 112 nT, and 90 nT, respectively. The DMSP spacecraft tend to report larger perturbations in the northern polar cap and cusp regions, especially during active intervals. We attribute some of the differences to limitations of spacecraft‐attitude knowledge that propagate into AMPERE data. Overall, for the magnetic storm, we provide clear evidence that AMPERE data can provide high‐resolution auroral zone data in good agreement with DMSP data for use in data assimilation algorithms. Such dual‐use commercial data can provide important global augmentation to the nation's space weather monitoring capabilities.

An Overview of Thunderstorm-Related Research on the Atmospheric Electric Field, Schumann Resonances, Sprites, and the Ionosphere at Sopron, Hungary

This paper gives a resume of the papers written in English which (a) describe some of the recording instruments in use at the Nagycenk Observatory (NCK) since the International Geophysical Year (IGY 1957–1958) and up to the present time, (b) summarise the most important and different types of observations associated with thunderstorms which have been made there, and (c) discuss their various geophysical interpretations. The paper describes the main results which have been obtained in four areas of thunderstorm associated atmospheric and geospace science within the context of Earth system science. These relate to the following parameters of atmospheric electricity: the vertical electric potential gradient just above the Earth’s surface and the air–Earth current as well as the point discharge current, Schumann resonance (SR) signals of the Earth-ionosphere cavity at 8, 14 and 20 Hz, transient luminous events (TLEs), and some aspects of the behaviour of the ionosphere. Deductions from these data sets are concerned with the global lightning activity and the conductivity of the air, with diurnal, seasonal, annual and long-term variations of the SR amplitudes and resonant frequencies in terms of migrating thunderstorm centres, with transient SR excitations and with sprites and other TLEs, and with ionospheric disturbances. The paper closes with some thoughts on future research directions based on the observations at NCK and Sopron and the results achieved since the IGY.

Wakimoto discusses role as NSF's incoming assistant director of geosciences

Roger Wakimoto's adrenaline “is starting to pump,” the incoming assistant director for geosciences (GEO) at the U.S. National Science Foundation (NSF) told Eos during an exclusive interview at this month's AGU Fall Meeting in San Francisco. Wakimoto, whose scientific expertise is in extreme weather, is scheduled to take charge as head of the NSF directorate for geosciences starting in February 2013. During his 4‐year appointment at NSF, Wakimoto, 59 and an avowed workaholic, will head up the GEO directorate, which has about an $880 million annual funding portfolio and provides about 55% of federal funding for geosciences basic research at U.S. academic institutions. The directorate currently includes the divisions of atmospheric and geospace sciences, Earth sciences, and ocean sciences. In addition, NSF's Office of Polar Programs is slated to become a GEO division under a realignment plan announced on 7 September; Wakimoto said that shift had “no bearing” on his decision to accept the position.

The US‐UK Space Weather Workshop

The US‐UK Space Weather Workshop