Imperial College London

DrMartinArcher

Faculty of Natural SciencesDepartment of Physics

Stephen Hawking Fellow (Advanced Research Fellow)
 
 
 
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Contact

 

+44 (0)20 7594 7661m.archer10 Website

 
 
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Location

 

6M58Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

73 results found

Hartinger MD, Elsden T, Archer MO, Takahashi K, Wright AN, Artemyev A, Zhang X, Angelopoulos Vet al., 2023, Properties of Magnetohydrodynamic normal modes in the Earth's magnetosphere, JGR: Space Physics, Vol: 128, ISSN: 2169-9402

The Earth's magnetosphere supports a variety of Magnetohydrodynamic (MHD) normal modes with Ultra Low Frequencies (ULF) including standing Alfvén waves and cavity/waveguide modes. Their amplitudes and frequencies depend in part on the properties of the magnetosphere (size of cavity, wave speed distribution). In this work, we use ∼13 years of Time History of Events and Macroscale Interactions during Substorms satellite magnetic field observations, combined with linearized MHD numerical simulations, to examine the properties of MHD normal modes in the region L > 5 and for frequencies <80 mHz. We identify persistent normal mode structure in observed dawn sector power spectra with frequency-dependent wave power peaks like those obtained from simulation ensemble averages, where the simulations assume different radial Alfvén speed profiles and magnetopause locations. We further show with both observations and simulations how frequency-dependent wave power peaks at L > 5 depend on both the magnetopause location and the location of peaks in the radial Alfvén speed profile. Finally, we discuss how these results might be used to better model radiation belt electron dynamics related to ULF waves.

Journal article

Zhou Y-J, He F, Zhang X-X, Archer MO, Lin Y, Ma H, Tian A-M, Yao Z-H, Wei Y, Ni B, Liu W, Zong Q-G, Pu Z-Yet al., 2023, A radial standing Pc5-6 wave and its energy coupling with field line resonance within the dusk-sector magnetosphere, JGR: Space Physics, Vol: 128, ISSN: 2169-9402

Global ultra-low frequency (ULF) oscillations are believed to play a significant role in the mass, energy, and momentum transport within the Earth's magnetosphere. In this letter, we observe a ∼1.2 mHz radial standing wave in the dusk-sector magnetosphere accompanied by the field line resonance (FLR) on 16 July 2017. The frequency estimation from the simple box model also confirms the radial standing wave. The essential characteristics of FLR are concurrently identified at the dusk-sector magnetosphere and the conjugated ground location. Further, the radial standing wave dissipates energy into upper atmosphere to enhance the local aurora by coupling itself to the FLR. The magnetospheric dominant 1.2/1.1 mHz ULF waves plausibly correspond well with the discrete ∼1 mHz magnetosheath ion dynamic pressure/velocity oscillation, suggesting this radial standing wave and FLR in the flank magnetosphere may be triggered by the solar-wind and/or magnetosheath dynamic pressure/velocity fluctuations.

Journal article

Collinson GA, Hietala H, Plaschke F, Karlsson T, Wilson LB, Archer M, Battarbee M, BlancoCano X, Bertucci C, Long D, Opher M, Sergis N, Gasque C, Liu T, Raptis S, Burne S, Frahm R, Zhang T, Futaana Yet al., 2023, Shocklets and short large amplitude magnetic structures (SLAMS) in the high mach foreshock of Venus, Geophysical Research Letters, Vol: 50, ISSN: 0094-8276

Shocklets and short large-amplitude magnetic structures (SLAMS) are steepened magnetic fluctuations commonly found in Earth's upstream foreshock. Here we present Venus Express observations from the 26th of February 2009 establishing their existence in the steady-state foreshock of Venus, building on a past study which found SLAMS during a substantial disturbance of the induced magnetosphere. The Venusian structures were comparable to those reported near Earth. The 2 Shocklets had magnetic compression ratios of 1.23 and 1.34 with linear polarization in the spacecraft frame. The 3 SLAMS had ratios between 3.22 and 4.03, two of which with elliptical polarization in the spacecraft frame. Statistical analysis suggests SLAMS coincide with unusually high solar wind Alfvén mach-number at Venus (12.5, this event). Thus, while we establish Shocklets and SLAMS can form in the stable Venusian foreshock, they may be rarer than at Earth. We estimate a lower limit of their occurrence rate of ≳14%.

Journal article

Archer M, Southwood D, Hartinger M, Rastatter L, Nykyri Ket al., 2023, Magnetosonic ULF waves with anomalous plasma - magnetic field correlations: standing waves and inhomogeneous plasmas, Geophysical Research Letters, Vol: 50, Pages: 1-13, ISSN: 0094-8276

Ultra-low frequency (ULF) wave observations across the heliosphere often rely on the sign of correlations between plasma (density/pressure) and magnetic field perturbations to distinguish between fast and slow magnetosonic modes. However, the assumptions behind this magnetohydrodynamic result are not always valid, particularly within the magnetosphere which is inhomogeneous and supports standing waves along the geomagnetic field. Through theory and a global simulation, we find both effects can result in anomalous plasma–magnetic field correlations. The interference pattern in standing waves can lead both body and surface magnetosonic waves to have different cross-phases than their constituent propagating waves. Furthermore, if the scale of gradients in the background are shorter than the wavelength or the waves are near-incompressible, then advection by the wave of inhomogeneities can overcome the wave's inherent sense of compression. These effects need to be allowed for and taken into account when applying the typical diagnostic to observations.

Journal article

Grimmich N, Plaschke F, Archer MO, Heyner D, Mieth JZD, Nakamura R, Sibeck DGet al., 2023, Study of extreme magnetopause distortions under varying solar wind conditions, JGR: Space Physics, Vol: 128, Pages: 1-22, ISSN: 2169-9402

To first order, the magnetopause (MP) is defined by a pressure balance between the solar wind and the magnetosphere. The boundary moves under the influence of varying solar wind conditions and transient foreshock phenomena, reaching unusually large and small distances from the Earth. We investigate under which solar wind conditions such extreme MP distortions occur. Therefore, we construct a database of magnetopause crossings (MPCs) observed by the THEMIS spacecraft in the years 2007 to mid-2022 using a simple Random Forest Classifier. Roughly 7% of the found crossing events deviate beyond reported errors in the stand-off distance from the Shue et al. (1998, https://doi.org/10.1029/98JA01103) MP model and thus are termed extreme distortions. We find the occurrence of these extreme events in terms of expansion or compression of the MP to be linked to different solar wind parameters, most notably to the IMF magnitude, cone angle, velocity, Alfvén Mach number and temperature. Foreshock transients like hot-flow anomalies and foreshock bubbles could be responsible for extreme magnetospheric expansions. The results should be incorporated into future magnetopause models and may be helpful for the reconstruction of the MP locations out of soft x-ray images, relevant for the upcoming SMILE mission.

Journal article

Kelly H, Archer M, Eggington J, Heyns M, Southwood D, Desai R, Eastwood J, Mejnertsen L, Chittenden Jet al., 2023, Formation and identification of Kelvin-Helmholtz generated vortices at Earths magnetopause: Insight from adapting hydrodynamic techniques for MHD

<jats:p>The Kelvin-Helmholtz Instability (KHI) plays a significant role in the viscous-like mass, momentum, and energy transfer from the solar wind into the magnetosphere through both vortical and wave dynamics. To confidently study and compare the effects of these dynamics, we must formally define a vortex. Previously, a definition did not exist for the magnetohydrodynamic (MHD) regime. Consequently, we have developed a novel vortex definition (the `&amp;#955;MHD definition&amp;#8217;) for MHD flows. This is based on adapting well-used hydrodynamic techniques (the &amp;#955;2 family of methods) that defines a vortex as a local minimum in an adapted pressure field. We derive the MHD suitable adapted pressure field from the ideal MHD Cauchy-Momentum equation, and find that it is composed of four components. The first three components represent the hydrodynamic properties of rotational momentum flow, density inhomogeneity, and fluid compressibility respectively. The final component makes the &amp;#955;MHD definition unique from hydrodynamics as it represents the rotational component of the J&amp;#215;B Lorentz force which is found using a Helmholtz decomposition. We use the Gorgon global 3-Dimensional MHD code to validate the &amp;#955;MHD vortex definition within a northward IMF simulation run exhibiting KHI-driven waves at the magnetopause flanks. Comparison of &amp;#955;MHD with existing hydrodynamic definitions shows good correlations and skill scores, particularly with the more advanced methods. Our analysis also reveals that the rotational momentum flow term dominates at the magnetopause. The other components provide typically small corrections to this. We have found that at the magnetopause, compressibility generally acts in opposition to the existence of a pressure minimum and thus a vortex. Alternatively, inhomogeneity and the rotational component of the Lorentz force generally act to support the pressure minimum. We explore

Other

Desai R, Eastwood J, Glauert S, Horne R, Eggington J, Heyns M, Archer M, Kelly H, Mejnertsen L, Chittenden Jet al., 2023, Resolving Multiscale Magnetospheric and Radiation Belt Dynamics using Global MHD, Test Particle and Fokker Planck Simulations

<jats:p>The global magnetosphere represents an intricate and multi-scale system with dynamics occurring across scales ranging from metres to miles and milli-seconds to days. This represents a formidable challenge to understand, and differing plasma theories are typically applied to model the large-scale electromagnetic fields and the dynamics of the Van Allen radiation belts. This discretisation of plasma regimes, however, breaks down during extreme conditions when the magnetosphere becomes highly distorted and energetic particle dynamics vary rapidly across sub-drift timescales. To self-consistently model both short and long timescales, we combine global MHD and particle simulations with Fokker-Planck simulations to demonstrate how this presents a realistic and also necessary method to capture magnetospheric and radiation belt dynamics during severe geomagnetic storms. The global MHD simulations capture the large-scale modulations to the global magnetic and electric fields and the integrated particle simulations reveal intense acceleration processes during the compression phase and subsequent injections through the magnetotail. At relativistic energies, loss processes at low L shells are limited and the Fokker-Planck model reveals how newly accelerated radiation belt distributions evolve and persist over extended time periods. Modelling this flow of energy from the solar wind through to ring current and radiation belt populations, across both short and long time-scales, requires detailed observational constraints and we discuss how upcoming space missions will help us to holistically constrain energy transfers through our puzzling magnetosphere.&amp;#160;</jats:p>

Other

Archer M, Hartinger M, Cottingham M, Shi X, Vidugiris E, Holland A, Harold J, Masongsong E, Hill D, Fox M, Coyle S, Alexander R, Pacini A, Candey Ret al., 2023, Lend Me Your Ears: Space Weather Citizen Science Through Harnessing Sonification

<jats:p>The changing conditions in near-Earth space cause space weather. This poses a risk to our everyday lives through the technology we rely upon through impacts on crucial power, communications, navigation, and transport systems. Analogues of sound in the space plasmas around our planet, known as Ultra Low Frequency (ULF) waves, are one means by which energy is circulated from the solar wind to the radiation belt, auroral, and ionospheric regions. Time-series data of ULF waves is often analysed visually, however, such data lends itself more naturally to our sense of sound. Guided by experts in audio, citizen science, and public engagement, we have developed sonification tools that render ULF waves audible. Alongside this, a graphical user interface has been developed, enabling citizen scientists to highlight signals within this audible data that standard methods can struggle to identify. These efforts are part of a NASA-funded pilot project called HARP (Heliophysics Audified Resonances in Plasmas), where high-school students and members of the public contribute to space weather science through listening. We provide an overview of how we carefully developed and tested this citizen science project before launching it publicly.</jats:p>

Other

Grimmich N, Plaschke F, Archer M, Heyner D, Mieth J, Nakamura R, Sibeck Det al., 2023, Statistical study of extreme magnetopause locations

<jats:p>The magnetopause (MP) is the boundary that separates the solar wind plasma from the Earth&amp;#8217;s (inner) magnetosphere. To first order, its equilibrium position is defined by the pressure balance across it. The boundary moves under the influence of varying solar wind conditions and transient foreshock phenomena, thereby sometimes reaching unusually large and small distances from Earth. We investigate the occurrence of such extreme MP distortions. Therefore, we construct a database of magnetopause crossings observed by the THEMIS spacecraft in the years 2007 to mid-2022 using machine learning techniques. Crossing events deviating from the Shue et al. (1998) MP model by more than the reported uncertainties are denoted as extreme distortions. The occurrences of these extreme events in terms of expansion or compression of the magnetosphere are linked to different solar wind parameters. The results should be applied to future magnetopause models and may be validated by MP observations in soft x-ray images by the upcoming SMILE mission.</jats:p>

Other

Archer M, Southwood D, Hartinger M, 2023, Anticorrelation of density and magnetic field in a fast magnetosonic mode: The case of surface waves in an inhomogeneous magnetosphere

<jats:p>Magnetohydrodynamic (MHD) wave theory states that fast magnetosonic waves should have correlated fluctuations in the compressional magnetic field and the plasma density / pressure. Anticorrelation, on the other hand relates either to the slow magnetosonic or mirror modes. These classic results are often used as a diagnostic in waves observed by spacecraft throughout the heliosphere. However, it is important to recognise that they are derived under the assumption of a homogeneous background plasma. Planetary magnetospheres are, in contrast, highly inhomogeneous. When allowing for a non-uniform background, the linearised MHD equations for density and pressure perturbations include terms due to the intrinsic compression associated with the wave as well as advection of plasma parcels with different background values. We argue that these two effects can compete and result in anticorrelation between the density and magnetic field, particularly when the scale of the inhomogeneity is shorter than that of the wave. We demonstrate examples of this anticorrelation applied to fast-mode magnetopause surface waves in both analytic MHD theory and a global MHD simulation. Finally, methods which identify and allow for these effects in satellite observations are discussed.</jats:p>

Other

Battarbee M, Archer M, Hietala H, Plaschke F, Palmroth M, Turc Let al., 2023, Morphology and evolution of foreshock structures in a high-Mach number hybrid-Vlasov simulation of Earth's magnetosphere

<jats:p>Counter-streaming particles reflected from the Earth's bow shock towards the Sun build up the ion foreshock, exciting right-handed ultra-low frequency (ULF) waves, which convect with the solar wind back to the bow shock. As these waves move Earthward, they steepen and interact with each other, forming a complex wave field consisting of various foreshock structures. Observations of foreshock structures have classified them as, for example, ULF waves, shocklets, short large-amplitude magnetic structures (SLAMS), cavitons, and spontaneous hot flow anomalies (SHFAs). We present results from a high Mach number 2D-3V hybrid-Vlasov Vlasiator simulation of the Earth's bow shock and foreshock&amp;#160;during quasi-radial IMF and place them in the context of spacecraft observations. We combine spatial analysis of bulk characteristics within the foreshock with virtual spacecraft observations to evaluate the morphology of foreshock structures as they form, and how they subsequently evolve as they approach the Earth's bow shock.</jats:p>

Other

Archer M, Hartinger MD, Rastatter L, Southwood D, Heyns M, Eggington J, Wright A, Plaschke F, Shi Xet al., 2023, Auroral, ionospheric and ground magnetic signatures of magnetopause surface modes, Journal of Geophysical Research: Space Physics, Vol: 128, Pages: 1-25, ISSN: 2169-9380

Surface waves on Earth's magnetopause have a controlling effect upon global magnetospheric dynamics. Since spacecraft provide sparse in situ observation points, remote sensing these modes using ground-based instruments in the polar regions is desirable. However, many open conceptual questions on the expected signatures remain. Therefore, we provide predictions of key qualitative features expected in auroral, ionospheric, and ground magnetic observations through both magnetohydrodynamic theory and a global coupled magnetosphere-ionosphere simulation of a magnetopause surface eigenmode. These show monochromatic oscillatory field-aligned currents (FACs), due to both the surface mode and its non-resonant Alfvén coupling, are present throughout the magnetosphere. The currents peak in amplitude at the equatorward edge of the magnetopause boundary layer, not the open-closed boundary as previously thought. They also exhibit slow poleward phase motion rather than being purely evanescent. We suggest the upward FAC perturbations may result in periodic auroral brightenings. In the ionosphere, convection vortices circulate the poleward moving FAC structures. Finally, surface mode signals are predicted in the ground magnetic field, with ionospheric Hall currents rotating perturbations by approximately (but not exactly) 90° compared to the magnetosphere. Thus typical dayside magnetopause surface modes should be strongest in the East-West ground magnetic field component. Overall, all ground-based signatures of the magnetopause surface mode are predicted to have the same frequency across L-shells, amplitudes that maximize near the magnetopause's equatorward edge, and larger latitudinal scales than for field line resonance. Implications in terms of ionospheric Joule heating and geomagnetically induced currents are discussed.

Journal article

Archer MO, Hartinger MD, Rastatter L, Southwood DJ, Heyns M, Eggington JWB, Wright AN, Plaschke F, Shi Xet al., 2022, Auroral, Ionospheric and Ground Magnetic Signatures of Magnetopause Surface Modes

Journal article

Archer M, Cottingham M, Hartinger M, Shi X, Coyle S, Hill E, Fox M, Masongsong Eet al., 2022, Listening to the magnetosphere: How best to make ULF waves audible, Frontiers in Astronomy and Space Sciences, Vol: 9, ISSN: 2296-987X

Observations across the heliosphere typically rely on in situ spacecraft observations producing time-series data. While often this data is analysed visually, it lends itself more naturally to our sense of sound. The simplest method of converting oscillatory data into audible sound is audification—a one-to-one mapping of data samples to audio samples—which has the benefit that no information is lost, thus is a true representation of the original data. However, audification can make some magnetospheric ULF waves observations pass by too quickly for someone to realistically be able to listen to effectively. For this reason, we detail various existing audio time scale modification techniques developed for music, applying these to ULF wave observations by spacecraft and exploring how they affect the properties of the resulting audio. Through a public dialogue we arrive at recommendations for ULF wave researchers on rendering these waves audible and discuss the scientific and educational possibilities of these new methods.

Journal article

Archer M, Waters C, Dewan S, Foster S, Portas Aet al., 2022, GC Insights: Space sector careers resources in the UK need a greater diversity of roles, Geoscience Communication, Vol: 5, Pages: 119-123, ISSN: 2569-7110

Educational research highlights that improved careers education is needed to increase participation in science, technology, engineering, and mathematics (STEM). Current UK careers resources concerning the space sector, however, are found to perhaps not best reflect the diversity of roles present and may in fact perpetuate misconceptions about the usefulness of science. We, therefore, compile a more diverse set of space-related jobs, which will be used in the development of a new space careers resource.

Journal article

Archer M, Waters C, Dewan S, Foster S, Portas Aet al., 2022, Developing a new space sector careers resource based on educational research recommendations

<jats:p>&amp;lt;p&amp;gt;Educational research shows participation issues across Science Technology Engineering and Mathematics (STEM) are due to whether students see these fields and their potential career opportunities as for &amp;amp;#8220;people like me&amp;amp;#8221;. These perceptions form early and remain relatively stable with age, which has led to recommendations for increased provision and quality of careers education/engagement at both primary and secondary levels. Space-related roles should be rife for inclusion in careers education resources. However, we find that current UK careers resources concerning the space sector do not perhaps best reflect the diversity of roles present and may in fact perpetuate misconceptions about the usefulness of science. We present the development process of a new space careers resource, detailing how we have attempted to improve the diversity of space-related careers highlighted as well as addressing the key issues and recommendations raised by recent educational research.&amp;lt;/p&amp;gt;</jats:p>

Journal article

Archer M, Southwood D, Hartinger M, Rastaetter L, Wright Aet al., 2022, How a realistic magnetosphere alters the polarizations of surface, fast magnetosonic, and Alfvén waves, Journal of Geophysical Research: Space Physics, Vol: 127, ISSN: 2169-9380

System-scale magnetohydrodynamic (MHD) waves within Earth's magnetosphere are often understood theoretically using box models. While these have been highly instructive in understanding many fundamental features of the various wave modes present, they neglect the complexities of geospace such as the inhomogeneities and curvilinear geometries present. Here, we show global MHD simulations of resonant waves impulsively excited by a solar wind pressure pulse. Although many aspects of the surface, fast magnetosonic (cavity/waveguide), and Alfvén modes present agree with the box and axially symmetric dipole models, we find some predictions for large-scale waves are significantly altered in a realistic magnetosphere. The radial ordering of fast mode turning points and Alfvén resonant locations may be reversed even with monotonic wave speeds. Additional nodes along field lines that are not present in the displacement/velocity occur in both the perpendicular and compressional components of the magnetic field. Close to the magnetopause, the perpendicular oscillations of the magnetic field have the opposite handedness to the velocity. Finally, widely used detection techniques for standing waves, both across and along the field, can fail to identify their presence. We explain how all these features arise from the MHD equations when accounting for a non-uniform background field and propose modified methods that might be applied to spacecraft observations.

Journal article

Archer M, Waters C, Dewan S, Foster S, Portas Aet al., 2022, GC Insights: Space sector careers resources need a greater diversity of roles

<jats:p>Abstract. Educational research highlights that improved careers education is needed to increase participation in STEM. Current careers resources concerning the space sector, however, are found to perhaps not best reflect the diversity of roles present and may in fact perpetuate misconceptions about the usefulness of science. We, therefore, compile a more diverse set of space-related jobs, which will be used in the development of a new space careers resource. </jats:p>

Journal article

Archer M, Hartinger M, Plaschke F, Southwood D, Rastaetter Let al., 2021, Magnetopause ripples going against the flow form azimuthally stationary surface waves, Nature Communications, Vol: 12, Pages: 1-14, ISSN: 2041-1723

Surface waves process the turbulent disturbances which drive dynamics in many space, astrophysical and laboratory plasma systems, with the outer boundary of Earth’s magnetosphere, the magnetopause, providing an accessible environment to study them. Like waves on water, magnetopause surface waves are thought to travel in the direction of the driving solar wind, hence a paradigm in global magnetospheric dynamics of tailward propagation has been well-established. Here we show through multi-spacecraft observations, global simulations, and analytic theory that the lowest-frequency impulsively-excited magnetopause surface waves, with standing structure along the terrestrial magnetic field, propagate against the flow outside the boundary. Across a wide local time range (09–15h) the waves’ Poynting flux exactly balances the flow’s advective effect, leading to no net energy flux and thus stationary structure across the field also. Further down the equatorial flanks, however, advection dominates hence the waves travel downtail, seeding fluctuations at the resonant frequency which subsequently grow in amplitude via the Kelvin-Helmholtz instability and couple to magnetospheric body waves. This global response, contrary to the accepted paradigm, has implications on radiation belt, ionospheric, and auroral dynamics and potential applications to other dynamical systems.

Journal article

Desai R, Eastwood J, Horne R, Allison H, Allanson O, Watt C, Eggington J, Glauert S, Meredith N, Archer M, Staples F, Mejnertsen L, Tong J, Chittenden Jet al., 2021, Drift orbit bifurcations and cross-field transport in the outer radiation belt: global MHD and integrated test-particle simulations, Journal of Geophysical Research: Space Physics, Vol: 126, Pages: 1-14, ISSN: 2169-9380

Energetic particle fluxes in the outer magnetosphere present a significant challenge to modellingefforts as they can vary by orders of magnitude in response to solar wind driving conditions. In thisarticle, we demonstrate the ability to propagate test particles through global MHD simulations to ahigh level of precision and use this to map the cross-field radial transport associated with relativisticelectrons undergoing drift orbit bifurcations (DOBs). The simulations predict DOBs primarily occurwithin an Earth radius of the magnetopause loss cone and appears significantly different for southwardand northward interplanetary magnetic field orientations. The changes to the second invariant areshown to manifest as a dropout in particle fluxes with pitch angles close to 90◦and indicate DOBsare a cause of butterfly pitch angle distributions within the night-time sector. The convective electricfield, not included in previous DOB studies, is found to have a significant effect on the resultant longterm transport, and losses to the magnetopause and atmosphere are identified as a potential methodfor incorporating DOBs within Fokker-Planck transport models.

Journal article

Desai RT, Freeman M, Eastwood J, Eggington J, Archer M, Shprits Y, Meredith N, Staples F, Ian R, Hietala H, Mejnertsen L, Chittenden J, Horne Ret al., 2021, Interplanetary shock-induced magnetopause motion: Comparison between theory and global magnetohydrodynamic simulations, Geophysical Research Letters, Vol: 48, Pages: 1-11, ISSN: 0094-8276

The magnetopause marks the outer edge of the Earth’s magnetosphere and a distinct boundary between solar wind and magnetospheric plasma populations. In this letter, we use global magneto-hydrodynamic simulations to examine the response of the terrestrial magnetopause to fast-forward interplanetary shocks of various strengths and compare to theoretical predictions. The theory and simulations indicate the magnetopause response can be characterised by three distinct phases; an initial acceleration as inertial forces are overcome, a rapid compressive phase comprising the majority of the distance travelled, and large-scale damped oscillations with amplitudes of the order of an Earth radius. The two approaches agree in predicting subsolar magnetopause oscillations with frequencies2–13 mHz but the simulations notably predict larger amplitudes and weaker damping rates. This phenomenon is of high relevance to space weather forecasting and provides a possible explanation for magnetopause oscillations observed following the large interplanetary shocks of August 1972 and March 1991.

Journal article

Archer MO, 2021, Schools of all backgrounds can do physics research – on the accessibility and equity of the Physics Research in School Environments (PRiSE) approach to independent research projects, Geoscience Communication, Vol: 4, Pages: 189-208, ISSN: 2569-7110

Societal biases are a major issue in school students' access to and interaction with science. School engagement programmes in science from universities, like independent research projects, which could try and tackle these problems are, however, often inequitable. We evaluate these concerns applied to one such programme, Physics Research in School Environments (PRiSE), which features projects in space science, astronomy, and particle physics. Comparing the schools involved with PRiSE to those of other similar schemes and UK national statistics, we find that PRiSE has engaged a much more diverse set of schools with significantly more disadvantaged groups than is typical. While drop-off occurs within the protracted programme, we find no evidence of systematic biases present. The majority of schools that complete projects return for multiple years with the programme, with this repeated buy-in from schools again being unpatterned by typical societal inequalities. Therefore, a school's ability to succeed in independent research projects appears independent of background within the PRiSE framework. Qualitative feedback from teachers shows that the diversity and equity of the programme, which they attribute to the level of support offered through PRiSE's framework, is valued, and they have highlighted further ways of making the projects potentially even more accessible. Researcher involvement, uncommon in many other programmes, along with teacher engagement and communication are found to be key elements to success in independent research projects overall.

Journal article

Archer MO, DeWitt J, 2021, “Thanks for helping me find my enthusiasm for physics”: the lasting impacts “research in schools” projects can have on students, teachers, and schools, Geoscience Communication, Vol: 4, Pages: 169-188, ISSN: 2569-7110

Using 6 years of evaluation data, we assess the medium- and long-term impacts upon a diverse range of students, teachers, and schools from participating in a programme of protracted university-mentored projects based on cutting-edge space science, astronomy, and particle physics research. After having completed their 6-month-long projects, the 14–18-year-old school students report having substantially increased in confidence relating to relevant scientific topics and methods as well as having developed numerous skills, outcomes which are corroborated by teachers. There is evidence that the projects helped increase students' aspirations towards physics, whereas science aspirations (generally high to begin with) were typically maintained or confirmed through their involvement. Longitudinal evaluation 3 years later has revealed that these projects have been lasting experiences for students which they have benefited from and drawn upon in their subsequent university education. Data on students' destinations suggest that their involvement in research projects has made them more likely to undertake physics and STEM degrees than would otherwise be expected. Cases of co-created novel physics research resulting from Physics Research in School Environments (PRiSE) has also seemed to have a powerful effect, not only on the student co-authors, but also participating students from other schools. Teachers have also been positively affected through participating, with the programme having influenced their own knowledge, skills, and pedagogy, as well as having advantageous effects felt across their wider schools. These impacts suggest that similar “research in schools” initiatives may have a role to play in aiding the increased uptake and diversity of physics and/or STEM in higher education as well as meaningfully enhancing the STEM environment within schools.

Journal article

Archer MO, DeWitt J, Thorley C, Keenan Oet al., 2021, Evaluating participants' experience of extended interaction with cutting-edge physics research through the PRiSE “research in schools” programme, Geoscience Communication, Vol: 4, Pages: 147-168, ISSN: 2569-7110

Physics in schools is distinctly different from, and struggles to capture the excitement of, university research-level work. Initiatives where students engage in independent research linked to cutting-edge physics within their school over several months might help mitigate this, potentially facilitating the uptake of science in higher education. However, how such initiatives are best supported remains unclear and understudied. This paper evaluates a provision framework, Physics Research in School Environments (PRiSE), using survey data from participating 14–18-year-old students and their teachers to understand their experience of the programme. The results show that PRiSE appears to provide much more positive experiences than typical university outreach initiatives due to the nature of the opportunities afforded over several months, which schools would not be able to provide without external input. The intensive support offered is deemed necessary, with all elements appearing equally important. Based on additional feedback from independent researchers and engagement professionals, we also suggest the framework could be adopted at other institutions and applied to their own areas of scientific research, something which has already started to occur.

Journal article

Archer MO, Day N, Barnes S, 2021, Demonstrating change from a drop-in space soundscape exhibit by using graffiti walls both before and after, Geoscience Communication, Vol: 4, Pages: 57-67, ISSN: 2569-7110

Impact evaluation in public engagement necessarily requires measuring change. However, this is extremely challenging for drop-in activities due to their very nature. We present a novel method of impact evaluation which integrates graffiti walls into the experience both before and after the main drop-in activity. The activity in question was a soundscape exhibit, where young families experienced the usually inaudible sounds of near-Earth space in an immersive and accessible way. We apply two analysis techniques to the captured before and after data – quantitative linguistics and thematic analysis. These analyses reveal significant changes in participants' responses after the activity compared to before, namely an increased diversity in language used to describe space and altered conceptions of what space is like. The results demonstrate that the soundscape was surprisingly effective at innately communicating key aspects of the underlying science simply through the act of listening. The impacts also highlight the power of sonification in stimulating public engagement, which, through reflection, can lead to altered associations, perceptions, and understanding. Therefore, we show that this novel approach to drop-in activity evaluation, using graffiti walls both before and after the activity and applying rigorous analysis to this data, has the power to capture change and, thus, have a short-term impact. We suggest that commonly used evaluation tools suitable for drop-in activities, such as graffiti walls, should be integrated both before and after the main activity in general, rather than only using them afterwards as is typically the case.

Journal article

Archer M, DeWitt J, Davenport C, Keenan O, Coghill L, Christodoulou A, Durbin S, Campbell H, Hou Let al., 2021, Going beyond the one-off: How can STEM engagement programmes with young people have real lasting impact?, Research for All, Vol: 5, Pages: 67-85, ISSN: 2399-8121

A major focus in the STEM public engagement sector concerns engaging withyoung people, typically through schools. The aims of these interventions areoften to positively affect students' aspirations towards continuing STEMeducation and ultimately into STEM-related careers. Most schools engagementactivities take the form of short one-off interventions that, while able toachieve positive outcomes, are limited in the extent to which they can havelasting impacts on aspirations. In this paper we discuss various differentemerging programmes of repeated interventions with young people, assessing whatimpacts can realistically be expected. Short series of interventions appearalso to suffer some limitations in the types of impacts achievable. However,deeper programmes that interact with both young people and those that influencethem over significant periods of time (months to years) seem to be moreeffective in influencing aspirations. We discuss how developing a Theory ofChange and considering young people's wider learning ecologies are required inenabling lasting impacts in a range of areas. Finally, we raise severalsector-wide challenges to implementing and evaluating these emergingapproaches.

Journal article

Archer M, 2021, Comment on gc-2020-35, Publisher: Copernicus GmbH

Other

Archer M, 2020, Reply to RC5, Publisher: Copernicus GmbH

Other

Archer M, 2020, Further reply to RC1, Publisher: Copernicus GmbH

Other

Archer M, 2020, Reply to RC3, Publisher: Copernicus GmbH

Other

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