‘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.


INTRODUCTION
The words 'Antarctic science' usually spark thoughts of icebergs, the vast white expanse of the Antarctic ice sheets and charismatic megafauna such as penguins and seals-images characteristic of the Antarctic region-but Antarctic science is not only focused on what happens within the Southern Ocean and Antarctic continent.Earth's coldest continent is also home to scientific programmes that look well beyond Antarctica, and beyond Earth itself.One such branch of science is solar-terrestrial physics, 'aimed at understanding the nature and dynamics of the solar atmosphere, and how it affects the Earth's upper atmosphere and geomagnetic field'. 1 The polar regions are 'space weather sentinels', 2 windows from which to observe interactions between Earth's atmosphere and the heliosphere.For Halley VI, a British Antarctic Survey research station in East Antarctica, the evolution of solar-terrestrial physics is literally built into its history.
Drawing on original archival research and interviews with British Antarctic Survey scientists, this paper provides an account of the co-evolution of Halley VI research station with solar-terrestrial physics in the second half of the twentieth century. 3To do so, it tracks the emergence of the Super Dual Auroral Radar Network (SuperDARN) project, an international collaboration that today includes participation by 10 different countries. 4ther histories have been written of SuperDARN, but are primarily concerned with the scientific goals and results of SuperDARN as a whole; 5 here I seek to provide a historical geographical perspective on the infrastructure, people and places behind the science, focused specifically on Halley, one of the first SuperDARN sites, and what this story can tell us about the operation of Antarctic stations and science.
The evolution of Halley's infrastructure and place within the British Antarctic Survey has been influenced by its role as a geophysical observatory, during a period of growth for solarterrestrial physics.Antarctic stations must be understood and interrogated not only as polar sites, but as places of science within networks stretching far beyond Antarctica.For a geophysical observatory like Halley, Antarctica is only part of the story, 'a platform which allows you to put instruments in the right geophysical spaces'. 6We must look beyond the ice to understand the evolution of Antarctic science and infrastructure in the twentieth century.
The first half of this paper provides an overview of Halley's history with geospace research via its participation in international geospace projects in the 1980s and 1990s.The second half connects this history to wider trends in public, political and scientific agendas between the 1960s and the present day, arguing that Halley's close relationship with solar-terrestrial physics has been an important part of the British Antarctic Survey's ability to respond to changes in policy and scientific priorities.Overall, this paper makes clear that we need to understand the evolution of Antarctic stations, both their material infrastructures and the priorities of Antarctic science, as part of international networks of science beyond Antarctica.
In doing so, this paper contributes to bodies of work within Antarctic humanities and social sciences that explore the science, cultures and spatialities of Antarctic stations and calls into 1 John R. Dudeney, Richard I. Kressman and Alan S. Rodger, 'Automated observatories for geospace research in polar regions', Antarctic Sci. 10 (2), 192-203 (1998), p. 193.
3 This paper is an output of the author's doctoral research on the historical geographies of Halley research station from 1956 to the present.The interviews and archival records that inform this paper are therefore a subset of the total research conducted for this project.Interviewees were selected on the basis of their experience either at Halley or in guiding the operation or science of Halley from British Antarctic Survey headquarters in Cambridge.For this paper, archival records from the Royal Society and British Antarctic Survey collections are used alongside secondary literature to supplement four in-depth interviews with key figures in the British Antarctic Survey space weather and atmosphere programmes from the 1960s to the present day, conducted between the summer of 2020 and end of 2022.
5 See: Raymond A. question assumptions about Antarctica's isolation and exceptionalism, instead focusing on the heterogeneity of both the Antarctic environment and human engagements with the continent, and Antarctica's entanglement with wider scientific and geopolitical trends.Within Antarctic scholarship there are multiple accounts of the history, spatiality and heterogeneity of Antarctica's research stations.Collis's work on Mawson and Mirnyy stations argued that attention to the spatiality of research stations is of value for three reasons: documenting unique sites; highlighting the heterogeneity of Antarctic spaces; and exploring how these spaces are produced through colonialism, laws, infrastructure, geopolitics and so on. 7In their exploration of stations situated on Ross Island and King George Island, O'Reilly and Salazar also note the value of enquiries into the materiality of Antarctic research. 8They argue that the increasing human population in Antarctica requires more exploration of place-making and living practices, but also note that 'all life in this place … is intricately connected to global supply chains that link Antarctic places to several cities and regions across the globe'. 9hese intricate connections result in complex motivations behind the establishment and maintenance of stations.Collis notes that Antarctica is 'comprised not only of ice but also of competing spatialities … the costly construction, design and siting of national stations on the continent is a key part of this competition'. 10The balance of cost, science and logistics in shaping the architecture of stations is also discussed by Davis in her history of McMurdo station. 11Such accounts also emphasize the heterogeneity of stations.Collis and Stevens argue that 'the assumption that [Antarctica's] human settlements and spatialities are identical is far from the case'. 12Pottier also emphasizes the complexity and multiplicity of Antarctica's inhabited spaces, including stations, in her exploration of the appropriation of space at Dumont D'Urville station, arguing that '[a]n Antarctic station is a lived space, the product of an environment, a history and the richness of the social interactions evolving within it'. 13 Beyond stations, Howkins describes how the environmental specificity of the McMurdo Dry Valleys goes against the 'flattening' of descriptions of Antarctica, encouraging future work to 'focus on embracing both distinctiveness and connectivity'. 14Others have noted the connections between Antarctic research and science and geopolitics in the wider world.This has often been used to argue against simplistic narratives of the 1959 Antarctic Treaty as the end of geopolitics in Antarctica.For example, Turchetti et al. describe the use of scientific internationalism as a 'valuable weapon of propaganda' by states such as the United States, Australia and the UK in the 1960s, 15 and Howkins considers how environmental authority and climate science in Antarctica have contributed to the creation and preservation of an exclusionary governance system-the Antarctic Treaty System-shaped by politics as much as it is by science. 16This is not a matter of questioning the importance of science produced on the continent, but of understanding the complex ways in which scientific and geopolitical goals inform and support each other.
This paper contributes a new and valuable case study to this literature.Following Collis and Pottier, it documents part of the history of a unique site-Halley-and explores how the station is a product of its environment, history and co-evolution with geospace science. 17As with Howkins' exploration of environmental authority in Antarctic governance, the role of geospace in British Antarctic science is political as well as scientific, and this paper explores the logistical, geopolitical and scientific factors that produced Halley's geospace science over time.Thus, following O'Reilly and Salazar and Howkins, this paper embraces both Halley's specificity and its entanglement with other regions and processes on Earth, and an even wider scientific endeavour extending into the cosmos. 18

A (very) brief history of Halley
Halley research station is a British Antarctic Survey geophysical research station on the Brunt Ice Shelf in Eastern Antarctica.It was established in 1956 by the Royal Society in preparation for the International Geophysical Year (IGY) of 1957-1958, a global scientific collaboration that saw an explosion of scientific activity in Antarctica.Although the IGY is perhaps best known for Earth-bound geophysics, Halley's scientific portfolio has always included atmospheric and solar-terrestrial physics, and the station is even named after an astronomer and physicist: Edmond Halley. 19Some of Halley's observation programmes, such as ozone and meteorology records, have been in continuous operation since the IGY.Halley was handed over to the Falkland Islands Dependencies Survey, the precursor to the British Antarctic Survey, in January 1959 and has been in continuous operation as a British Antarctic Survey station since. 20here have been six versions of Halley to date, as a combination of ice accumulation and the movement of the Brunt Ice Shelf have necessitated regular replacement of the station buildings.The first, the Royal Society IGY Base, was a simple wooden hut that rapidly became buried by snow accumulation.The following three stations also suffered from snow accumulation and burial: Halley II, a pair of two-storey wooden buildings; Halley III, built inside metal armco tubes; and Halley IV, built inside wooden tubes.Halley V was the first above-ground station, and operated for over 10 years.Halley VI opened in 2012, another above-ground design of brightly-coloured blue and red modules equipped with skis, so that the station can be repositioned on the ice shelf in response to shelf dynamics.Halley is, and has been since the IGY, a platform for studying the atmosphere, space weather and glaciology.Halley has been part of the World Meteorological Organization's Global Atmosphere Watch programme since 2013 and was the third Antarctic station to join the programme.Halley data contributes to weather forecasting, climate change research and forecasting and understanding the impact of space weather, through both domestic and international projects.Halley is also isolated and experiences long periods of darkness, making it a terrestrial proxy for space flight.This has enabled Halley staff to take part in and support space flight research through the European Space Agency and in collaboration with Concordia, the French-Italian research station in Antarctica. 21Halley is a key site for the British Antarctic Survey's research on space weather and atmosphere, and it is the development of this field that is the subject of this paper.

Antarctica and geospace
Solar-terrestrial physics is concerned with a region called geospace, a collective term for the regions of the near-Earth space environment where Earth's magnetic field and the solar wind interact.These regions-the thermosphere, ionosphere and magnetosphere-were previously studied separately.The term 'geospace' emerged in the 1980s to collectively describe these regions in which the 'ionosphere,22 magnetosphere and solar wind form a closely coupled system'. 23Halley has been a site for ionospheric observation since the IGY, and today its instrumentation and scientific mandate has evolved to include geospace as a whole system.
The advantages of the polar regions-'windows to geospace' 24 -for solar-terrestrial physics are further amplified at Halley, which has been a 'springboard' for British Antarctic Survey research on the ionosphere and other regions of geospace. 25First, Halley is radio quiet, isolated from radio interference generated by things such as fluorescent lights or cars.Halley's high latitude means it is at the end of the magnetic field lines that also converge on Earth in the northern hemisphere, linking it with northern hemisphere observatories in a phenomenon called conjugation.Placing observatories at conjugate locations in the northern and southern hemisphere enables measurements to be taken simultaneously at both ends of the field line (conjugate measurements), a method that is highly valuable for research into a range of geospace phenomena and processes, such as energy flow in the ionosphere.Making these measurements in two conjugate locations allows scientists to investigate how flows vary with geomagnetic conditions, and with both latitude and longitude.Moreover, Halley sits beneath the South Atlantic anomaly, a weakness in Earth's magnetic field that allows high energy particles to penetrate closer to the Earth's surface. 26alley has therefore been equipped since the IGY with a growing suite of instruments aimed at monitoring components of the near-Earth system, which today has evolved into a dedicated research team on space weather and atmosphere.From the IGY, where programmes were divided into specific areas of inquiry such as ionospheric physics or auroral observation, to the emergence of 'geospace' science and today's Space Weather and Atmosphere Programme, this research is an integral part of Halley.
Halley was also a foundational part of the SuperDARN, an international project using ground-based high frequency radars to study dynamic processes in the ionosphere and magnetosphere.SuperDARN radars, of which there are now more than 30, have been used to map ionospheric convection and measure energy flow into and out of the magnetosphere, among other processes. 27With involvement by Australia, Canada, China, France, Italy, Japan, Norway, the UK, the USA and South Africa, and hundreds of papers published over the last four decades, SuperDARN is an active and successful collaboration emblematic of the highly international nature of both geospace and Antarctic science.
Halley's role as a geospace observatory is the result of a dual-track evolution of scientific priorities and capabilities in the UK and internationally, connected in part by existing relationships between the people involved (see figure 1).From the IGY onwards, external projects have aligned in useful ways with British Antarctic Survey/Halley research.
Halley exemplifies how histories of science are shaped by heterogeneous actors and events, all of which had to align in the right times and places to produce the outcomes they did.Halley's location, UK government priorities, British Antarctic Survey strategy, staff connections and advances in geospace instrumentation all converged in the 1980s to enable Halley-and, more broadly, the British Antarctic Survey-to take part in international geospace projects and contribute to UK policies focused on applied science.As the field of solar-terrestrial physics has grown, so has Halley's instrumentation and infrastructure, resulting in a sophisticated multi-instrument site.

FROM HALLEY TO HELIOSPHERE: EMERGING INFRASTRUCTURES
The co-evolution of Halley's infrastructure and instrumentation with geospace science can best be tracked through the installation of key instruments and their roles in international scientific collaborations throughout the 1980s and 1990s.These instruments marked significant jumps in Halley's (and the British Antarctic Survey's) capacity for geospace observation and research, and were made possible by evolving technologies and the British Antarctic Survey's international connections throughout this period.

The Advanced Ionospheric Sounder
The first major jump in Halley's ionospheric instrumentation came at the beginning of the 1980s.The British Antarctic Survey's Atmospheric Science Division collaborated with American academics in the Space Environment Laboratory in Boulder, Colorado, in the late 1970s to install a new type of ionosonde at Halley: the Advanced Ionospheric Sounder (AIS).This was an expensive programme that resulted in a technical jump for British Antarctic Survey ionospheric physics, including working with satellite data via American Halley and the evolution of geospace science collaborators.This led into a science programme at the British Antarctic Survey called Energy Flow in Geospace, aimed at understanding energy from the Sun through the magnetosphere and into the ionosphere.The 1980/81 British Antarctic Survey Annual Report describes the AIS as 'by far the most important BAS project this season'. 28nstalling the AIS also pushed the British Antarctic Survey to develop new infrastructures at Halley.The AIS had to be kept above ground, unlike the station buildings, which, at the time, were gradually buried by snow accumulation.The AIS was installed in containers with extending legs and a sledge base, a design later reflected in the structure of Halley V, the first above-ground version of Halley.The AIS masts were the largest ever erected by the British Antarctic Survey, and the amount of data produced required the creation of an entirely new data management system. 29ith new and more powerful instrumentation, the British Antarctic Survey was now at the frontier of a new field of research: geospace.By the late 1980s, geospace research was a growing field with international importance, with Halley at the centre of the British Antarctic Survey's efforts.The primary objective was 'to understand the processes which govern the transfer of energy from the solar wind into the magnetosphere, ionosphere and thermosphere, regions known collectively as geospace'; the author concluded that 'Halley is ideally located for studies of these effects'. 30The AIS not only provided the British Antarctic Survey with enhanced ionospheric instrumentation, but also laid the foundation for future changes to British Antarctic Survey science strategy and Halley's infrastructure and, alongside other discoveries, put Halley on a strong footing within British Antarctic Survey's wider scientific portfolio: After the 80s we became a very big player in Antarctica, and Halley became a very important station.Not merely because of the discovering of the ozone hole but because of the things that we were doing in other areas of science, and in particular in the area of space, what we used to call Geospace science. 31is trajectory continued in the late 1980s with new instrumentation and collaborations that led to Halley becoming a founding part of the SuperDARN network.

PACE, SHARE and SuperDARN
The combination of established collaborations, the British Antarctic Survey's emerging scientific priorities, Halley's location and its growing suite of instruments positioned Halley to become part of a rapid growth in international geospace science in the 1980s.Understanding this requires travelling through several different initiatives from the 1970s to the 1990s, many of which overlap in complex ways.A simplified version of this is presented in figure 1.First, I consider the Dual Auroral Radar Network (DARN).
DARN consisted of high frequency (HF) and very high frequency ground-based coherentbackscatter radar arrays with 'the unique capability of providing global-scale observations of the structure and dynamics of plasma convection and electric fields in the auroral zones and polar caps'. 32Coherent back-scatter radars are used to detect ionospheric irregularities, primarily in the E-region (90-130 km altitude) and F-region (above 150 km) of the ionosphere.Their design and use underwent significant development in the 1970s and 1980s.The first extensive use of these radars was via the Scandinavian Twin Auroral Radar Experiment (STARE), which consisted of two radar arrays in Malvik, Norway, and Hankasalmi, Finland, with a common viewing area over northern Scandinavia.STARE was used to study the structure and dynamics of plasma convection in the ionosphere.Further paired radar systems were later developed including the Sweden and Britain Radar Experiment (SABRE, Scotland and Sweden) and Bistatic Auroral Radar System (BARS, Ontario and Saskatchewan).These radars were part of a proposal submitted to NASA's Origins of Plasmas in the Earth's Neighborhood mission under the title of DARN. 33TARE was focused exclusively on the E-region of the ionosphere, and it eventually became apparent that there were limitations to both this approach and the STARE radars.New techniques were therefore developed using radars capable of observing both the E and F regions.The Johns Hopkins University Advanced Physics Laboratory (JHU/APL) developed a prototype of the new generation of HF coherent-backscatter radars, installed at Goose Bay, Labrador.34 The British Antarctic Survey became involved when one of their senior atmospheric scientists, Dr John Dudeney, heard about the Goose Bay radar and made plans for the 'most ambitious conjugate experiment ever taken'.35 Due to the tilt of the Earth's magnetic axis, Halley station is located very near to a point of magnetic conjugation with Goose Bay-an advantage not planned for in either the location of the Royal Society's IGY base nor the position of the Goose Bay radar.The Halley radar creates a conjugate field of view with Goose Bay of >3 million km 3 .36 Dudeney was able to persuade both the British Antarctic Survey and JHU/APL to engage in a collaborative project installing a second radar at Halley, titled the Polar Anglo-American Conjugate Experiment, or PACE.37 While the Goose Bay and Halley radars represented a technological step forward, they had a critical limitation: they were single radars, unlike the paired radars of STARE, SABRE and BARS.This limited researchers' ability to obtain vector velocity data, and required making assumptions to constrain data that were found to potentially lead to serious errors.It was concluded that bi-directional radars were required, and a radar previously located in Scandinavia was moved to Schefferville, Quebec, to pair with the Goose Bay system.38 For Halley, the British Antarctic Survey embarked on a collaboration with JHU/APL and the South African National Antarctic Programme to install a radar at the South African Antarctic station, SANAE.This was referred to as the Southern Hemisphere Auroral Radar Experiment (SHARE).
In 1990 it was formally decided that the international community would develop a globalscale bi-directional radar network, given the name SuperDARN to demonstrate that it was an expansion in scope of the original DARN project.Figure 1 illustrates this timeline, focusing on the dual evolution of projects external and internal to the British Antarctic Survey.This begins with the IGY, which both established Halley and led to an expansion of international science focused on the ionosphere.The development of the STARE radar in 1975 set the foundation for the more advanced Goose Bay radar to be built in 1983.Halley's growing suite of instruments, given a boost by the AIS in 1980, its location conjugate to Goose Bay and existing connections between American scientists and the British Antarctic Survey's ionospheric research allowed scientists like John Dudeney to connect Halley with the American projects, leading to PACE and later to SuperDARN. 39ritish Antarctic Survey involvement with SuperDARN has had a striking impact on Halley's infrastructure.The main antenna array for a SuperDARN radar typically consists of 16 antennas that transmit and receive HF radio signals.Most SuperDARN radars also have a receive-only four-antenna array for interferometry, although Halley does not. 40The antenna array added an arresting visual element to Halley's infrastructure, disrupting the flat white expanse of the Brunt Ice Shelf around the station.Today the British Antarctic Survey also operates a radar in the Falkland Islands and hosts a SuperDARN data hub.The SuperDARN project has contributed to cornerstone science programmes at the British Antarctic Survey and plays a key role in work of the space weather and atmosphere team. 41he British Antarctic Survey describes SuperDARN as 'one of the most successful tools for studying dynamical processes in the Earth's magnetosphere, ionosphere and neutral atmosphere'. 42SuperDARN was initially planned to have eight northern hemisphere radars and two southern hemisphere radars. 43There are now over 30 radars in the northern and southern hemispheres, organized by 16 principal investigator institutes in 10 countries. 44he network has over 900 published papers and the Halley radar has been employed in several of its key discoveries. 45he original goal of PACE and SuperDARN was the study of plasma convection in the ionosphere, but SuperDARN is a flexible piece of equipment.Its achievements represent its ability to grow beyond the original scope; it has been successfully leveraged in key work on the regions of the magnetosphere, ionosphere dynamics, ultra low frequency waves and upper atmospheric winds and tides. 46Achieving these successes requires good spatial coverage and multi-instrument sites, making Halley an important part of this global scientific network.Application of results from SuperDARN includes research into how magnetic storms and auroral activity affect atmospheric drag on satellites and the associated change to collision risk. 47The Halley radar increased the prominence of British Antarctic Survey geospace science at home and internationally: We entered a large international group of such radars, so it gave us really access to global data on the earth's ionosphere.And also, the importance of our science had increased greatly […] it started out as studying the Earth's ionosphere […] this is sort of expanded into what we now call space weather.As mankind puts more and more satellites up into space, we need space weather forecasting, because satellites are damaged by activity in the sun. 48e role of the SuperDARN radar in putting the British Antarctic Survey's geospace science 'on the map', particularly regarding the importance of forecasting space weather, is further discussed in the next section of this paper.Moreover, by bringing the British Antarctic Survey into that international research community, Halley's radar facilitated British Antarctic Survey involvement in further international collaborations, including the Global Geospace Science Project.

Going global from Halley
DARN and SuperDARN were one of the ground-based contributions to an international solarterrestrial physics (ISTP) initiative called the Global Geospace Science (GGS) project.ISTP was a collaborative effort by NASA, the European Space Agency and Japan's Institute of Space and Astronomical Science, consisting of international missions investigating the Sun-Earth space environment via satellite data, ground-based observations and theoretical modelling. 49GS aimed to quantify the interactions of the coupled system of the solar wind, magnetosphere and ionosphere, and was 'designed to improve greatly the understanding of the flow of energy, mass, and momentum in the solar-terrestrial environment with particular emphasis on "geospace"'. 50GGS combined satellites, ground-based experiments, theorists and modellers.Multiple spacecrafts were placed into orbit to focus on different elements of the geospace system: GEOTAIL (Japan); SOHO and CLUSTER (Europe); INTERBALL (Russia); and WIND and POLAR (US). 51ritish Antarctic Survey involvement in GGS was via SuperDARN and a project titled Satellite Experiments Simultaneous with Antarctic Measurements (SESAME).Raymond Greenwald at JHU/APL was the principal investigator (PI) for DARN, with John Dudeney at British Antarctic Survey as PI for SESAME.The role of DARN was to 'provide a global context for the spatially separated measurements provided by the ISTP/GGS spacecraft'. 52SESAME was about capitalizing on the geophysical advantages of Antarctica, centred on Halley and using automated geophysical observatories (AGOs) developed by the British Antarctic Survey through the 1980s/1990s and deployed poleward of Halley. 53These experiments were primarily located at Halley and AGOs poleward of Halley, with supporting data from Faraday station.The suite of instruments included an ionosonde, fluxgate magnetometers and VLF/ELF receivers, with many observations made continuously since the IGY.
The British Antarctic Survey also had an active geospace theory group at the time, led by Professor Richard Horne, which was working to generate analytical and numerical models.The theory group was not formally part of SESAME but did provide input.Ground-based data from British Antarctic Survey was combined with satellite data: the solar wind and interplanetary magnetic field from WIND, particle and wave data from GEOTAIL and particle, wave and electric field data from POLAR. 54ESAME took advantage of the British Antarctic Survey's multi-instrumented facilities in Antarctica, combined with WIND's data on the solar wind and magnetic field, GEOTAIL's particle and wave data and POLAR's particle, wave and electric field data.SESAME was to study a set of processes within geospace: merging of the solar wind with Earth's magnetic field, by which solar wind energy transfers into the magnetosphere/ionosphere at high latitudes; substorm processes, including initiation, position within the magnetosphere, extent, periodicity and so on; mapping of geospace boundaries, with a view to improving modelling of the magnetic field, including using approaches successfully used in the PACE project; ionospherethermosphere coupling in which the flow of energy throughout the geospace system was monitored; and wave-particle interactions important to numerous macroscopic geospace processes and to understanding the generation, propagation and dissipation of plasma waves. 55he British Antarctic Survey instruments used by SESAME included: the Halley SuperDARN radar; the AIS; the Fabry-Perot interferometer, riometer and magnetometer; and the VLF/ELF experiments that had been recording natural and artificial radio signals at Halley since 1967. 56ince the beginnings of its IGY ionospheric physics programme, Halley has emerged as a powerful multi-instrument site capable of significant contributions to the international geospace community, driven by its participation in collaborative international science.
However, British Antarctic Survey priorities and Halley science are not solely determined by the priorities of the international geospace science community.As a publicly funded organization via the UK's Natural Environment Research Council, British Antarctic Survey is affected by changes in government policy.Throughout the 1980s and 1990s, changing public and policy priorities, expressed through UK science strategies and Antarctic policy, seemed to be looking in the opposite direction from long-term geophysical observation.The next part of this paper explores how Halley's upwards-looking global science found its place in a world in which life sciences took on increasing prominence, and UK policy demanded quantifiable benefits for UK citizens from government-funded science.

BRINGING IT BACK HOME: UK SCIENCE POLICY AND THE STRATEGIC BENEFITS OF GEOSPACE
Halley exemplifies the complex interaction of geopolitics and science in Antarctica.This is partly the result of its location, which, alongside its geophysical advantages, is also at the edge of a region subject to overlapping claims by Britain and Argentina, and Britain's only permanent station in East Antarctica.It is well established that it is not only science but also 'practical geopolitical reasoning' that shapes states' activity in Antarctica. 57 A. E. Oates its establishment during the IGY, to subsequent decisions to replace past versions of Halley despite the costs of operating on the Brunt Ice Shelf, the geopolitics of Halley's location has been an important element in justifying maintaining a station in a location that regularly presents expensive operational challenges.Territorial competition with Argentina was a factor both in the decisions to establish the station and the choice to keep it open after the close of the IGY in 1959. 58Although the 1959 Antarctic Treaty 'froze' territorial claims, maintaining a presence in Antarctica on behalf of the UK remains part of the British Antarctic Survey's mission, and Halley, as the only British station in East Antarctica, is undoubtedly an important part of how British Antarctic Survey fulfils this requirement. 59owever, Halley's location is not the only aspect of the station with geopolitical and policy relevance.In this section I will discuss how geospace research, centred on Halley, played an important part in facilitating the British Antarctic Survey's response to a changing science and policy landscape.
Throughout the 1980s and 1990s the British Antarctic Survey was growing its atmosphere and geospace science programme, centred on Halley.Through these efforts, British Antarctic Survey made, and continues to make, contributions to international collaborations via the projects described here and others such as groups associated with the European Space Agency and the Scientific Committee on Antarctic Research (SCAR).
Aside from the direct scientific benefits of the AIS and SuperDARN radar at Halley, these programmes also played a key strategic role in a period of flux regarding UK government policy on science and science funding: first, the 'environmental shift' of the late 1960s and 1970s, which has been widely discussed by historians of science;60 second, UK science policy began to increasingly prioritize science that could deliver tangible benefits for the British economy and quality of life for British society, exemplified by policy documents such as Realising our potential (1993), discussed in the following sections of this paper. 61ntarctic science more often has global impact than specific quantifiable benefits for the UK and, as a geophysical observatory conducting long-term fundamental science, Halley could have been severely affected by these shifts.I argue that a key part of the reason it retained relevance was the British Antarctic Survey's ability to leverage geospace programmes to fit changing priorities in government and the international community-in fact, 'you can probably say that [geospace research] kept Halley going'. 62e environmental turn One indicator of those changing priorities was the turn towards environmental/life sciences in the late 1960s and 1970s.Halley was established at a high point for fundamental geophysical science and its role consisted of collecting long-term datasets such as ozone, auroral and ionospheric observations.In the late 1960s, the prominence of geophysics began to give way to an environmental movement that influenced both public opinion and international scientific priorities.Graf argues that 'if the 1960s had been a decade of seemingly limitless possibilities, in the 1970s people allegedly awoke to the realization of limits'. 63here was also significant institutional growth around this environmental turn, including in Antarctic science. 64In the late 1960s and 1970s the World Meteorological Organization, the International Council of Scientific Unions (now the International Science Council), the Council of Europe, the UN and the SCAR all established new institutions or projects focused on life sciences, the environment and global monitoring.
In the UK, the Department of the Environment, with in-house experts advising on climate change, was established in 1970, with centres of climate change research at the University of East Anglia and the Meteorological Office.The 1976 drought hammered home the potential implications of climate change for UK citizens, prompting further institutional growth around climate change.Margaret Thatcher's 1988 speech to the Royal Society added further urgency to the growing climate change research community. 65he 'environmental turn' was as present in British Antarctic science as in other research communities, evident as early as the 1960s when the IGY and the success of geophysical science were still fresh.In a debate in the UK House of Lords in 1963, it was argued that 'the biological sciences are trailing behind the physical sciences' and that it would be biological sciences, not 'physical sciences or space research', that would determine the future of humanity. 66f papers submitted to the first Antarctic Treaty Consultative Meeting in 1961, more were on conservation of fauna and flora than anything else, 67 and the British Antarctic Survey dedicated its Signy station to biological sciences in the same year. 68the British Antarctic Survey was heavily involved in a SCAR project titled BIOMASS, an international programme of research into Antarctic marine living resources with a view to their 'rational' control and use.British Antarctic Survey director Richard Laws was appointed UK permanent delegate to SCAR, convenor of SCAR's Specialist Group on Seals, part of the SCAR Working Group on Biology, and was part of the BIOMASS executive and associated groups.The BIOMASS executive decided in 1984 to establish a BIOMASS data centre at the British Antarctic Survey. 69British Antarctic Survey was aligning itself with the environmental turn.
The main relevance of this to Halley is that biological sciences was largely conducted at other stations or field sites. 70The shift from geophysics to biological sciences therefore had the potential to reduce the value of Halley.This is compounded by the fact that the international Antarctic research community was equally focused on life sciences, driven by a need to understand Antarctic ecosystems and the potential impacts of exploitation.
All of this equates to 'a fundamental change of perception and reinterpretation of the human world around 1970'. 71Moreover, the scientific community faced increasing financial and cultural pressures moving into the 1980s.British Antarctic science suffered a decline in funding throughout the 1970s that culminated in a decision to withdraw the UK's only ice patrol ship, HMS Endurance, in 1981/82. 72Even in this period, Halley's location, later so vital to the SuperDARN project, mattered: the Halley rebuild (Halley III to Halley IV) was approved despite financial stringencies, 'because of the exceptional importance of its location in relation to geophysical phenomena'. 73his funding crisis was averted by the onset of the Falklands War in 1982, which reaffirmed the strategic value of the South Atlantic for the British government and resulted in a ring-fenced funding boost for the British Antarctic Survey and stay of execution for Endurance. 74The Falklands War was 'the most influential motive underlying and precipitating British government decisions with respect to Antarctica during 1982-3'. 75 few years later, Halley's data resulted in the discovery of the hole in the ozone layer over Antarctica, leading to the Montreal Protocol banning chlorofluorocarbons.These two events firmly placed the British Antarctic Survey, and fundamental geophysical science, back on the strategic map.

Realizing our potential?
Antarctic science was now in a more secure position regarding funding, but the British Antarctic Survey was still operating in a context where environmental science was highly valued, and British science was coming under increasing pressure to prove its impact.The Antarctic research community has often had to respond quickly to these changes to keep and expand access to funding and to defend the value of Antarctic science.Moreover, changes to funding models in the 1990s put added pressure on British Antarctic Survey scientists to justify the value of their work; different fields of research within British Antarctic Survey had to compete for funds with each other and with other research institutions.One of the key criteria for winning funding was global relevance, and climate change science was particularly valued. 76olicymakers were increasingly focused on ensuring that publicly funded science would offer direct returns for British people, through either economic stimulation or improvements to quality of life.A 1993 White Paper titled Realising our potential was a major milestone in this shift. 77Realising our potential mandated a focus on science providing value for the British public, bringing in the 'quality of life' language that is prevalent after this point: The Government wishes to harness the intellectual resources of the science and engineering base to improve economic performance and the quality of life.It intends, in future, that decision on priorities for support should be much more clearly related to meeting the country's needs and enhancing the wealth-creating capacity of the country. 78 the world of 'realizing our potential' there was a general turn towards applied science that offered measurable benefits for taxpayers.Science had to be competitive, and it had to strengthen the UK science and industry base.So how did the British Antarctic Survey respond?
Realizing our Antarctic potential: the British Antarctic Survey response UK science strategy filtered down to the British Antarctic Survey via the Natural Environment Research Council (NERC), which now had a mission to 'promote and support, by any means, high quality basic, strategic and applied research' alongside long-term environmental monitoring.NERC was to 'advance knowledge and technology […] thereby contributing to the economic competitiveness of the UK, the effectiveness of public services and policy and the quality of life' and to promote public and policy understanding of the scientific fields under their purview. 79For the British Antarctic Survey, this translated to a mission to: undertake a world-class programme of science in the Antarctic and related regions, addressing key global and regional issues through research, survey and monitoring, and including the maintenance and development of necessary facilities and infrastructure. 80 so doing they would support NERC's mission and sustain a regional UK presence and leadership in Antarctica.Words such as 'effective', 'leadership', 'world-class' and 'flexible' are regularly used to define the approach to science in this period in documents such as the British Antarctic Survey business plans and annual reports; the value of science is clearly not considered self-evident enough to forgo such qualifiers.
Atmospheric and geospace research feature heavily in British Antarctic Survey's response to the Realising our potential White Paper.In the 1993/1994 Annual Report for example, the foreword from NERC's chief executive describes the impact on the British Antarctic Survey, which has been 'relatively unchanged' by Research Council restructures, but has been 'affected by the White Paper intentions to develop the UK research base to contribute more effectively to wealth creation, economic wellbeing and the quality of life'.The British Antarctic Survey has, he continues, responded to these requirements primarily 76  A. E. Oates through global environmental change research that related to the quality of life theme.It is also noted that 'work carried out by BAS in atmospheric sciences, glaciology and the life sciences demonstrates the value of long-term observations made by an organization such as BAS'. 81he inclusion of atmospheric sciences in this list is a hint to the continuing prominence of Halley science in the changing policy landscape.The British Antarctic Survey director's introduction further affirms this, while tempering adherence to the UK government's aims with a commitment to international partners, such as the 'international and legally-binding framework of the Antarctic Treaty'.While the British Antarctic Survey commits to exploring 'the opportunity and spin-off from its scientific research to transfer, improve connections and benefit the wealth creating aspects of national life', the director emphasizes that 'the Antarctic's most immediate benefit will continue to be the revelation, understanding and long-term monitoring of globally relevant environmental issues', including atmospheric chemistry. 82he 1994/1995 Annual Report continues the discussion about the British Antarctic Survey's response to the White Paper, and more explicitly mentions Halley science.Both the NERC chief executive and the British Antarctic Survey director specifically mention Halley science in their introductions, and demonstrate two of the branches of Halley science that have best enabled the British Antarctic Survey to respond to policy demands on science: atmospheric science, represented notably by the hole in the ozone layer, and geospace.For the NERC chief executive, the British Antarctic Survey's discovery of the ozone hole is a useful example of Antarctic science with direct impact on British citizens: Although Antarctica may at first sight seem remote and little connected to issues of relevance to the UK, on closer inspection this is not the case.Two spectacular examples (involving BAS science) of how events in Antarctica have an impact on day-to-day life in the UK are the role of the circumpolar current in ultimately determining our weather and climate and the well known 'ozone hole' discovered in Antarctica. 83nce its discovery, the ozone hole is one of the most cited discoveries when it comes to defence of the reputation, necessity and funding of British Antarctic science, and Britain's leadership in international Antarctic affairs.This is demonstrated by how frequently it appeared in debates in the UK's parliament-about Antarctica or otherwise-as the prime example of Britain's influence and leadership in global science. 84It appears in debate questions about space policy, 85 NERC funding 86 and the balance between applied and basic research. 87Throughout the late 1980s and early 1990s, the hole in the ozone layer was the example used to demonstrate that British science was worthy of public funds, that the British Antarctic Survey was a world-leading institution and that basic science could produce the kind of benefits for British society that were increasingly sought after by government and the research councils.The British Antarctic Survey even credited the ozone hole discovery with drawing public attention to Antarctica, arguing that it 'gave publicity to and emphasized the vital importance of Antarctica in our understanding of the natural environment and its responses to Man'. 88he ozone discovery was a tangible, serendipitous outcome of long-term Antarctic science, and has thus been an important cornerstone of defences of the British Antarctic Survey's existence and budgets ever since.However, it is not the only part of Halley science that has played this role.Returning to the same 1994/1995 Annual Report in which the NERC executive director lauded the ozone discovery, the British Antarctic Survey's director chose to focus on a different aspect of their science, equally connected to Halley-space weather: Modern navigation systems, communications networks and Earth observations are all critically dependent upon the weather in space.Storms in geospace can cause major disruptions to these, and can affect terrestrial power systems and cause radiation damage to high altitude travellers.Although the strategic value of geospace is immense, it remains one of the least explored regions of the Earth's environment. 89e practical applications of geospace science, particularly space weather forecasting, supported the British Antarctic Survey's need to produce science with tangible benefits for the UK, and respond to the international community's increasing focus on climate and global change.For example, its work on Sun-Earth connections and applications for understanding climate variability was used to argue against a decision by the Science and Technology Facilities Council to reduce the budget for ground-based solar-terrestrial physics to zero in 2009.The issue was debated in the House of Commons, with the British Antarctic Survey contribution lauded as 'the clearest evidence that we received'. 90British Antarctic Survey's account focused on Sun-climate links, with Halley's programme of research into upper atmosphere physics specifically mentioned.Solar influence on the near-Earth space environment and the corresponding effect on critical national infrastructure and satellites-and therefore the insurance industry-is also mentioned. 91pace weather became a dedicated strand of research at the British Antarctic Survey, particularly through the EU projects SPACECAST and SPACESTORM, which put in place a forecasting system for space weather using data from Halley and British Antarctic Survey computer models, with the aim of protecting satellites from radiation damage caused by space weather. 92espite the prominence of climate research and life sciences in recent decades, programmes such as space weather research have facilitated a continued prominence for Halley's geophysical science within the wider British Antarctic Survey portfolio.It is not inconceivable that the 'environmental turn' and the growing focus on climate change research could have relegated Halley's geophysical programmes to a lower profile.Instead, the combination of ozone and geospace have maintained the UK government's interest in space weather and atmosphere research in Antarctica, and Halley is 'delivering on all of those fronts'. 93The high-level, collaborative, policy-relevant work of the atmosphere and geospace programmes, balanced against these other trends, has significantly contributed to maintaining Halley's relevance into the twenty-first century. 94

CONCLUSION
To fully understand the history of Antarctic scientific sites it is necessary to expand our frame of reference beyond the ice, even beyond the Earth itself.Halley research station and geospace are entwined throughout their respective histories, and investigating their co-evolution illustrates the reciprocal interaction of politics, science and the material environment in shaping Halley's history.
For Halley to become entwined in the international geospace world required identification of priority areas by government decision-makers, an accompanying recognition of a scientific need by the Antarctic scientists, people with the correct expertise and international connections, the logistical capabilities of the British Antarctic Survey, and the location of the station.The role of serendipity is also interesting; Halley's precise location was determined not by foreknowledge of projects such as SuperDARN, but by ice dynamics that pushed the Royal Society expedition to pick the Brunt Ice Shelf for the Royal Society IGY base in 1955. 95qually, Halley's growing suite of instrumentation shaped Halley in return, connecting it to an international community of scientists and instruments, positioning Halley within the British Antarctic Survey's emerging geospace research and shaping the station itself with new instruments and their associated infrastructure, such as new data links for AIS data and the SuperDARN antenna array.The outputs of the atmospheric and geospace programmes at Halley, particularly the ozone discovery and space weather research, have helped protect Halley's future by demonstrating the value of long-term geophysical science in Antarctica to those deciding UK science policy and funding.
In this paper I have provided a novel account of the emergence of the SuperDARN project, a wide-reaching internationally organized cooperative, in operation for 30 years and with a successful and high output.In doing so I have also demonstrated that the trajectory of by SPACESTORM, which continued the forecasting element of SPACECAST and developed risk indicators for assessing the risk to satellites from space weather: Spacestorm, 'SPACESTORM' (n.d.), https://www.spacestorm.eu/(accessed 25 March 2024).Halley magnetometer data is one part of the data input into these projects: interview with R.H. by the author, 14 September 2020.
93 Interview with M.P. by the author, 21 August 2020.94 It is possible that non-geospace scientists within British Antarctic Survey might contest this account of how important geospace has been in regard to Antarctic science and policy in Britain, and that individuals involved with the space weather and atmosphere programme, beyond those interviewed here, may give a different account of events.However, as these voices were not present in the material accessed in researching this paper, it is not possible to provide a counterfactual history within this paper.Instead, I acknowledge that this is not a comprehensive history and that future research would benefit from the inclusion of a wider range of voices in regard to both geospace and other fields of science.
Halley and the evolution of geospace science

Figure 1 .
Figure 1.Diagram describing the evolution of projects that led to the establishment of Halley as a key site for international solar-terrestrial physics.The blue box in the centre refers to factors that facilitated connection between projects external to the British Antarctic Survey and their existing work and instrumentation.