Mervyn Freeman

Science Leader

Biography

I am Leader of the Space Weather and Atmosphere Team at the British Antarctic Survey.

In 2017, I was awarded the Chapman medal of the Royal Astronomical Society for investigations of outstanding merit in solar-terrestrial physics. My main research theme has been an holistic view of the coupled solar wind-magnetosphere-ionosphere system by the synthesis of experiment, data analysis and theory, including the development of new simple mathematical models to explain observations and resolve controversies, e.g., in ionospheric convection and substorms. I have published over 100 papers in peer-reviewed journals.

Since 2013, I have been the UK Research and Innovation (UKRI) Delegate to the European Incoherent Scatter (EISCAT) Council, responsible for the activities of the EISCAT Scientific Association. The Association is an international organisation that operates radars in Norway, Sweden, and Finland to investigate the upper atmosphere and ionosphere. Together with UK colleagues, Ian McCrea, Yulia Bogdanova, Steve Crothers (RAL Space), and Andrew Kavanagh (BAS), I oversee and support the UK’s scientific exploitation of EISCAT, including a £6M UK capital investment in the new EISCAT-3D radar, which is due to begin operations in 2022.

Career history

Leader, Space Weather and Atmosphere Team, British Antarctic Survey, 2022-
Promotion to UKRI Band G, 2024
Honorary Professor, Mullard Space Science Laboratory, University College London, 2019-2024
Chapman medal, Royal Astronomical Society, 2017
Deputy Leader, Space Weather and Atmosphere Team, British Antarctic Survey, 2015-2022
UK Research and Innovation (UKRI) Delegate to the European Incoherent Scatter (EISCAT) Council, 2013-
Senior Space Weather Researcher, Radiation Belts and Atmospheric Chemistry Workpackage, British Antarctic Survey, 2013-2015
Manager, Natural Complexity Workpackage, British Antarctic Survey, 2009-2013
Principal Investigator, Halley SuperDARN radar, 2005-2016, and Falkland Islands SuperDARN radar, 2009-2011
Principal Investigator, Natural Complexity Programme, British Antarctic Survey, 2005-2009
Principal Investigator, BAS Low Power Magnetometer Network, 2000-
Project leader, Magnetic Reconnection Project, British Antarctic Survey, 2000-2005
Promotion to Band 4, British Antarctic Survey, 2000-
Senior Scientific Officer, British Antarctic Survey, 1991-2000
Research Assistant, Imperial College, London, UK, 1991
Visiting Postdoctoral Fellow, Johns Hopkins University Applied Physics Laboratory, Maryland, USA, 1990-1991
Research Assistant, Imperial College, London, UK, 1989
PhD Space Physics, Imperial College, London, UK, 1986-1989
BSc (Hons) Physics, Imperial College, London, UK, 1983-1986

Research interests

Universal properties and theory of substorms at Earth and other planets.
Multi-scale structure and turbulence of plasma convection and currents in Earth’s ionosphere.
Modes of variability of the geomagnetic field.
Space weather and its applications.
Geoelectric circuit influences on climate.
Cross-disciplinary applications of natural complexity.

Collaborations

European Incoherent Scatter (EISCAT) Scientific Association

NERC Space Weather Impact on Ground-based Systems (SWIGS) Highlight Topic grant 2017-2021 (including 10 UK institutes and universities)

STFC Rutherford Appleton Laboratory RAL Space group

Super Dual Auroral Radar Network (SuperDARN)

University College London Mullard Space Science Laboratory

Publications from NERC Open Research Archive

2024

Lao, C.J., Forsyth, C., Freeman, Mervyn , Smith, A.W., Mooney, M.K.. (2024) On the Association of Substorm Identification Methods. JGR Space Physics, 129 (). 16 pp. 10.1029/2024JA032762

Parker, William E., Freeman, Mervyn , Chisham, Gareth , Kavanagh, Andrew John , Siew, Peng Mun, Rodriguez-Fernandez, Victor, Linares, Richard. (2024) Influences of Space Weather Forecasting Uncertainty on Satellite Conjunction Assessment. Space Weather, 22 (). 19 pp. 10.1029/2023SW003818

Chisham, G. , Freeman, M. P. . (2024) The spatial variation of large- and meso-scale plasma vorticity statistics in the high-latitude ionosphere and implications for ionospheric plasma flow models. Journal of Geophysical Research: Space Physics, 129 (). 21 pp. 10.1029/2024JA032887

Carter, J.A., Dunlop, M., Forsyth, C., Oksavik, K., Donovon, E., Kavanagh, A. , Milan, S.E., Sergienko, T., Fear, R.C., Sibeck, D.G., Connors, M., Yeoman, T., Tan, X., Taylor, M.G.G.T., McWilliams, K., Gjerloev, J., Barnes, R., Billet, D.D., Chisham, G. , Dimmock, A., Freeman, M.P. , Han, D.-S., Hartinger, M.D., Hsieh, S.-Y.W., Hu, Z.-J., James, M.K., Juusola, L., Kauristie, K., Kronberg, E.A., Lester, M., Manuel, J., Matzka, J., McCrea, I., Miyoshi, Y., Rae, J., Ren, L., Sigernes, F., Spanswick, E., Sterne, K., Steuwer, A., Sun, T., Walach, M.-T., Walsh, B., Wang, C., Weygand, J., Wild, J., Yan, J., Zhang, J., Zhang, Q.-H.. (2024) Ground-based and additional science support for SMILE. Earth and Planetary Physics, 8 (). 24 pp. 10.26464/epp2023055

2023

Coyle, S.E., Baker, J.B.H., Chakraborty, S., Hartinger, M. D., Freeman, M.P. , Clauer, C.R., Xu, Z., Weimer, D.R.. (2023) Substorms and Solar Eclipses: A Mutual Information Based Study. Geophysical Research Letters, 50 (). 7 pp. 10.1029/2023GL106432

Coxon, J.C., Chisham, G. , Freeman, M.P. , Forsyth, C., Walach, M-T., Murphy, K.R., Vines, S.K., Anderson, B.J., Smith, A.W., Fogg, A.R.. (2023) Extreme Birkeland Currents Are More Likely During Geomagnetic Storms on the Dayside of the Earth. Journal of Geophysical Research: Space Physics, 128 (). 16 pp. 10.1029/2023JA031946

Chisham, G. , Freeman, M.P. . (2023) Separating contributions to plasma vorticity in the high-latitude ionosphere from large-scale convection and meso-scale turbulence. Journal of Geophysical Research: Space Physics, 128 (). 13 pp. 10.1029/2023JA031885

Lam, M.M. , Shore, R.M. , Chisham, G. , Freeman, M.P. , Grocott, A., Walach, M.-T., Orr, L.. (2023) A Model of High Latitude Ionospheric Convection Derived From SuperDARN EOF Model Data. Space Weather, 21 (). 17 pp. 10.1029/2023SW003428

Coyle, S.E., Hartinger, M.D., Clauer, C.R., Baker, J.B.H., Cnossen, I. , Freeman, M.P. , Weygand, J.M.. (2023) The 2021 Antarctic Total Eclipse: Ground Magnetometer and GNSS Wave Observations from the 40 Degree Magnetic Meridian. Journal of Geophysical Research: Space Physics, 128 (). 12 pp. 10.1029/2022JA031142

Maffei, Stefano, Eggington, Joseph W. B., Livermore, Philip W., Mound, Jonathan E., Sanchez, Sabrina, Eastwood, Jonathan P., Freeman, Mervyn P. . (2023) Climatological predictions of the auroral zone locations driven by moderate and severe space weather events. Scientific Reports, 13 (). pp. 10.1038/s41598-022-25704-2

Orr, L., Grocott, A., Walach, M.‐T., Chisham, G. , Freeman, M.P. , Lam, M.M. , Shore, R.M. . (2023) A quantitative comparison of high latitude electric field models during a large geomagnetic storm. Space Weather, 21 (). 24 pp. 10.1029/2022SW003301

2022

Engebretson, Mark J., Simms, Laura E., Pilipenko, Viacheslav A., Bouayed, Lilia, Moldwin, Mark B., Weygand, James M., Hartinger, Michael D., Xu, Zhonghua, Clauer, C. Robert, Coyle, Shane, Willer, Anna N., Freeman, Mervyn P. , Gerrard, Andy J.. (2022) Geomagnetic disturbances that cause GICs: investigating their interhemispheric conjugacy and control by IMF orientation.. Journal of Geophysical Research: Space Physics, 127 (). 23 pp. 10.1029/2022JA030580

Smith, A.W., Rodger, C.J., Manus, D.H. Mac, Forsyth, C., Rae, I.J., Freeman, M.P. , Clilverd, M.A. , Petersen, T., Dalzell, M.. (2022) The correspondence between sudden commencements and geomagnetically induced currents: Insights from New Zealand. Space Weather, 20 (). 18 pp. 10.1029/2021SW002983

Daggitt, Thomas A. , Horne, Richard B. , Glauert, Sarah A. , Del Zanna, Giulio, Freeman, Mervyn P. . (2022) Variations in Observations of Geosynchronous Magnetopause and Last Closed Drift Shell Crossings with Magnetic Local Time. Space Weather, 20 (). 13 pp. 10.1029/2022SW003105

Coxon, John C., Chisham, Gareth , Freeman, Mervyn P. , Anderson, Brian J., Fear, Robert C.. (2022) Distributions of Birkeland current density observed by AMPERE are heavy‐tailed or long‐tailed. Journal of Geophysical Research: Space Physics, 127 (). 20 pp. 10.1029/2021JA029801

2021

Chisham, G. , Freeman, M.P. . (2021) A statistical model of vorticity in the polar ionosphere and implications for extreme values. Journal of Geophysical Research: Space Physics, 126 (). 16 pp. 10.1029/2021JA029307

Bentley, Mike, Siegert, Martin, Jones, Anna , Meredith, Michael , Hendry, Katharine, Arthur, Jennifer, Brooks, Ian, Convey, Peter , Dodds, Klaus, Freeman, Mervyn , Hughes, Kevin A. , Johnston, Nadine M. , Marschalek, Jim, Nichols, Keir, Plaschkes, Charlotte, Rhodes, Rachael, Taylor, Michelle L.. (2021) The future of UK Antarctic science: Strategic priorities, essential needs and opportunities for international leadership. Imperial College London, The Grantham Institute, 10 pp. (Grantham Institute Discussion Paper 9.) 10.25561/92181

Desai, R.T., Freeman, M.P. , Eastwood, J.P., Eggington, J.W.B., Archer, M.O., Shprits, Y.Y., Meredith, N.P. , Staples, F.A., Rae, I.J., Hietala, H., Mejnertsen, L., Chittenden, J.P., Horne, R.B. . (2021) Interplanetary shock‐induced magnetopause motion: Comparison between theory and global magnetohydrodynamic simulations. Geophysical Research Letters, 48 (). 11 pp. 10.1029/2021GL092554

Shore, R.M. , Freeman, M.P. , Chisham, G. . (2021) Data‐driven basis functions for SuperDARN ionospheric plasma flow characterisation and prediction. Journal of Geophysical Research: Space Physics, 126 (). 18 pp. 10.1029/2021JA029272

Smith, A.W., Forsyth, C., Rae, I.J., Rodger, C.J., Freeman, M.P. . (2021) The impact of sudden commencements on ground magnetic field variability: Immediate and delayed consequences. Space Weather, 19 (). 17 pp. 10.1029/2021SW002764

Dimmock, A.P., Welling, D.T., Rosenqvist, L., Forsyth, C., Freeman, M.P. , Rae, I.J., Viljanen, A., Vandegriff, E., Boynton, R.J., Balikhin, M.A., Yordanova, E.. (2021) Modeling the geomagnetic response to the September 2017 space weather event over Fennoscandia using the Space Weather Modeling Framework: Studying the impacts of spatial resolution. Space Weather, 19 (). 25 pp. 10.1029/2020SW002683

Clilverd, Mark , Rodger, Craig J., Freeman, Mervyn P. , Brundell, James B., Mac Manus, Daniel H., Dalzell, Michael, Clarke, Ellen, Thomson, Alan W.P., Richardson, Gemma S., MacLeod, Finlay, Frame, Ian. (2021) Geomagnetically induced currents during the 07-08 September 2017 disturbed period: a global perspective. Journal of Space Weather and Space Climate, 11 (). 15 pp. 10.1051/swsc/2021014

2020

Smith, A.W., Rae, I.J., Forsyth, C., Oliveira, D.M., Freeman, M.P. , Jackson, D.R.. (2020) Probabilistic forecasts of storm sudden commencements from interplanetary shocks using machine learning. Space Weather, 18 (). 24 pp. 10.1029/2020SW002603

Engebretson, Mark J., Kirkevold, Kathryn R., Steinmetz, Erik S., Pilipenko, Viacheslav A., Moldwin, Mark B., McCuen, Brett A., Clauer, C. R., Hartinger, Michael D., Coyle, Shane, Opgenoorth, Hermann, Schillings, Audrey, Willer, Anna N., Edwards, Thom R., Boteler, David H., Gerrard, Andy J., Freeman, Mervyn P. , Rose, Michael C.. (2020) Interhemispheric comparisons of large nighttime magnetic perturbation events relevant to GICs. Journal of Geophysical Research: Space Physics, 125 (). 24 pp. 10.1029/2020JA028128

2019

Smith, A.W., Freeman, M.P. , Rae, I.J., Forsyth, C.. (2019) The influence of sudden commencements on the rate of change of the surface horizontal magnetic field in the United Kingdom. Space Weather, 17 (). pp. 10.1029/2019SW002281

Freeman, Mervyn , Lam, Mai Mai. (2019) Regional, seasonal, and inter-annual variations of Antarctic and sub-Antarctic temperature anomalies related to the Mansurov effect. Environmental Research Communications, 11 (). pp. 10.1088/2515-7620/ab4a84

Sandhu, J.K., Rae, I.J., Freeman, M.P. , Gkioulidou, M., Forsyth, C., Reeves, G.D., Murphy, K.R., Walach, M.-T.. (2019) Substorm ‐ Ring Current Coupling: A comparison of isolated and compound substorms. Journal of Geophysical Research: Space Physics, 124 (). pp. 10.1029/2019JA026766

Coxon, John C., Shore, Robert M. , Freeman, Mervyn P. , Fear, Robert C., Browett, Stephen D., Smith, Andrew W., Whiter, Daniel K., Anderson, Brian J.. (2019) Timescales of Birkeland Currents driven by the IMF. Geophysical Research Letters, 46 (). pp. 10.1029/2018GL081658

Shore, R.M. , Freeman, M.P. , Coxon, J.C., Thomas, E.G., Gjerloev, J.W., Olsen, N.. (2019) Spatial variation in the responses of the surface external and induced magnetic field to the solar wind. Journal of Geophysical Research: Space Physics, 124 (). pp. 10.1029/2019JA026543

Shore, Robert , Freeman, Mervyn , Gjerloev, Jesper. (2019) Interplanetary magnetic field control of polar ionospheric equivalent current system modes. Space Weather, 17 (). pp. 10.1029/2019SW002161

Freeman, Mervyn P. , Forsyth, Colin, Rae, I. Jonathan. (2019) The influence of substorms on extreme rates of change of the surface horizontal magnetic field in the United Kingdom. Space Weather, 17 (). pp. 10.1029/2018SW002148

Lam, Mai Mai , Freeman, Mervyn P. , Jackman, C.M., Rae, I.J., Kalmoni, N.M.E., Sandhu, J.K., Forsyth, C.. (2019) How well can we estimate Pedersen conductance from the THEMIS white-light all-sky cameras?. Journal of Geophysical Research: Space Physics, 124 (). pp. 10.1029/2018JA026067

Lockwood, Mike, Bentley, Sarah N., Owens, Mathew J., Barnard, Luke A., Scott, Chris J., Watt, Clare E., Allanson, Oliver, Freeman, Mervyn P. . (2019) The development of a space climatology: 3. Models of the evolution of distributions of space weather variables with timescale. Space Weather, 17 (). pp. 10.1029/2018SW002017

Lockwood, Mike, Bentley, Sarah N., Owens, Mathew J., Barnard, Luke A., Scott, Chris J., Watt, Clare E., Allanson, Oliver, Freeman, Mervyn P. . (2019) The development of a space climatology: 2. The distribution of power input into the magnetosphere on a 3‐hourly timescale. Space Weather, 17 (). pp. 10.1029/2018SW002016

2018

Lam, Mai Mai , Freeman, Mervyn P. , Chisham, Gareth . (2018) IMF-driven change to the Antarctic tropospheric temperature due to the global atmospheric electric circuit. Journal of Atmospheric and Solar-Terrestrial Research, 180 (). pp. 10.1016/j.jastp.2017.08.027

Sandhu, J.K., Rae, I.J., Freeman, Mervyn P. , Forsyth, C., Gkioulidou, M., Reeves, G.D., Spence, H.E., Jackman, C.M., Lam, M.M.. (2018) Energization of the ring current by substorms. Journal of Geophysical Research: Space Physics, 123 (). pp. 10.1029/2018JA025766

Coxon, John C., Freeman, Mervyn P. , Jackman, Caitriona M., Forsyth, Colin, Rae, I. Jonathan, Fear, Robert C.. (2018) Tailward propagation of magnetic energy density variations With respect to substorm onset times. Journal of Geophysical Research: Space Physics, 123 (). pp. 10.1029/2017JA025147

Forsyth, C., Shortt, M., Coxon, J.C., Rae, I.J., Freeman, M.. , Kalmoni, N.M.E., Jackman, C.M., Anderson, B.J., Milan, S.E., Burrell, A.G.. (2018) Seasonal and temporal variations of field-aligned currents and ground magnetic deflections during substorms. Journal of Geophysical Research: Space Physics, 123 (). pp. 10.1002/2017JA025136

Shore, R.M. , Freeman, M.P. , Gjerloev, J.W.. (2018) An empirical orthogonal function reanalysis of the northern polar external and induced magnetic field during solar cycle 23. Journal of Geophysical Research, 123 (). pp. 10.1002/2017JA024420

2017

Shore, R.M. , Freeman, M.P. , Wild, J.A., Gjerloev, J.W.. (2017) A high-resolution model of the external and induced magnetic field at the Earth’s surface in the northern hemisphere. Journal of Geophysical Research: Space Physics, 122 (). pp. 10.1002/2016JA023682

2016

Forsyth, C., Rae, I. J., Murphy, K. R., Freeman, M. P. , Huang, C.-L., Spence, H. E., Boyd, A. J., Coxon, J. C., Jackman, C. M., Kalmoni, N. M. E., Watt, C. E. J.. (2016) What effect do substorms have on the content of the radiation belts?. Journal of Geophysical Research: Space Physics, 121 (). pp. doi:10.1002/2016JA022620

Coxon, J. C., Jackman, C. M., Freeman, M. P. , Forsyth, C., Rae, I. J.. (2016) Identifying the magnetotail lobes with Cluster magnetometer data. Journal of Geophysical Research: Space Physics, 121 (). pp. doi:10.1002/2015JA022020

2015

Forsyth, C., Rae, I. J., Coxon, J. C., Freeman, M. P. , Jackman, C. M., Gjerloev, J., Fazakerley, A. N.. (2015) A new technique for determining Substorm Onsets and Phases from Indices of the Electrojet (SOPHIE). Journal of Geophysical Research: Space Physics, 120 (). pp. doi:10.1002/2015JA021343

2014

Forsyth, C., Watt, C.E.J., Rae, I.J., Fazakerley, A.N., Kalmoni, N.M.E., Freeman, M.P. , Boakes, P.D., Nakamura, R., Dandouras, I., Kistler, L.M., Jackman, C.M., Coxon, J.C., Carr, C.. (2014) Increases in plasma sheet temperature with solar wind driving during substorm growth phases. Geophysical Research Letters, 41 (). pp. doi:10.1002/2014GL062400

Longden, N., Chisham, G. , Freeman, M.P. . (2014) Magnetic local time variation and scaling of poleward auroral boundary dynamics. Journal of Geophysical Research: Space Physics, 119 (). pp. 10.1002/2014JA020430

Lam, Mai Mai , Chisham, Gareth , Freeman, Mervyn . (2014) Solar-wind-driven geopotential height anomalies originate in the Antarctic lower troposphere. Geophysical Research Letters, 41 (). pp. 10.1002/2014GL061421

Jackman, C. M., Arridge, C. S., André, N., Bagenal, F., Birn, J., Freeman, M. P. , Jia, X., Kidder, A., Milan, S. E., Radioti, A., Slavin, J. A., Vogt, M. F., Volwerk, M., Walsh, A. P.. (2014) Large-scale structure and dynamics of the magnetotails of Mercury, Earth, Jupiter and Saturn. Space Science Reviews, 182 (). pp. doi:10.1007/s11214-014-0060-8

Jackman, C.M., Slavin, J. A, Kivelson, M.G., Southwood, D. J., Achilleos, N., Thomsen, M.F., DiBraccio, G. A., Eastwood, J.P., Freeman, M.P. , Dougherty, M.K., Vogt, M.F.. (2014) Saturn’s dynamic magnetotail: A comprehensive magnetic field and plasma survey of plasmoids and travelling compression regions, and their role in global magnetospheric dynamics. Journal of Geophysical Research: Space Physics, 119 (). pp. doi:10.1002/2013JA019388

2013

Lam, Mai Mai , Chisham, Gareth , Freeman, Mervyn P. . (2013) The interplanetary magnetic field influences mid-latitude surface atmospheric pressure. Environmental Research Letters, 8 (). pp. 10.1088/1748-9326/8/4/045001

Milan, S. E., Grocott, A., de Larquier, S., Lester, M., Yeoman, T. K., Freeman, M. P. , Chisham, G. . (2013) Traveling ionospheric disturbances in the Weddell Sea Anomaly associated with geomagnetic activity. Journal of Geophysical Research: Space Physics, 118 (). pp. doi:10.1002/jgra.50566

Chisham, Gareth , Freeman, Mervyn P. . (2013) A reassessment of SuperDARN meteor echoes from the upper mesosphere and lower thermosphere. Journal of Atmospheric and Solar-Terrestrial Physics, 102 (). pp. 10.1016/j.jastp.2013.05.018

Grocott, A., Hosokawa, K., Ishida, T., Lester, M., Milan, S. E., Freeman, M. P. , Sato, N., Yukimatu, A. S.. (2013) Characteristics of medium-scale traveling ionospheric disturbances observed near the Antarctic Peninsula by HF radar. Journal of Geophysical Research: Space Physics, 118 (). pp. doi:10.1002/jgra.50515

Capparelli, V., Franzke, C., Vecchio, A., Freeman, M.P. , Watkins, N.W., Carbone, V.. (2013) A spatiotemporal analysis of U.S. station temperature trends over the last century. Journal of Geophysical Research: Atmospheres, 118 (). pp. 10.1002/jgrd.50551

Moffat-Griffin, Tracy , Lester, Mark, Freeman, Mervyn . (2013) From atmosphere to space: a new scientific frontier. Astronomy & Geophysics, 54 (). pp. doi:10.1093/astrogeo/att079

2012

Kunduri, B.S.R., Baker, J.B.H., Ruohoniemi, J. M., Clausen, L.B.N., Grocott, A., Thomas, E.G., Freeman, M.P. , Talaat, E.R.. (2012) An examination of inter-hemispheric conjugacy in a subauroral polarization stream. Journal of Geophysical Research, 117 (). 17 pp. 10.1029/2012JA017784

Edwards, Andrew M., Freeman, Mervyn P. , Breed, Greg A., Jonsen, Ian D.. (2012) Incorrect likelihood methods were used to infer scaling laws of marine predator search behaviour. Plos One, 7 (). 13 pp. 10.1371/journal.pone.0045174

2011

Grocott, A., Milan, S.E., Baker, J.B.H., Freeman, M.P. , Lester, M., Yeoman, T.K.. (2011) Dynamic subauroral ionospheric electric fields observed by the Falkland Islands radar during the course of a geomagnetic storm. Journal of Geophysical Research, 116 (). 16 pp. 10.1029/2011JA016763

Boakes, P.D., Milan, S.E., Abel, G.A., Freeman, M.P. , Chisham, G. , Hubert, B.. (2011) A superposed epoch investigation of the relation between magnetospheric solar wind driving and substorm dynamics with geosynchronous particle injection signatures. Journal of Geophysical Research, 116 (). 12 pp. 10.1029/2010JA016007

Hibbins, Robert , Freeman, Mervyn , Milan, S.E., Ruohoiemi, J.M.. (2011) Winds and tides in the mid-latitude Southern Hemisphere upper mesosphere recorded with the Falkland Islands SuperDARN radar. Annales Geophysicae, 29 (). pp. 10.5194/angeo-29-1985-2011

2010

Longden, Nicola, Chisham, Gareth , Freeman, Mervyn P. , Abel, Gary A., Sotirelis, Tom. (2010) Estimating the location of the open-closed magnetic field line boundary from auroral images. Annales Geophysicae, 28 (). pp. 10.5194/angeo-28-1659-2010

Chisham, G. , Freeman, M.P. . (2010) On the non-Gaussian nature of ionospheric vorticity. Geophysical Research Letters, 37 (). 5 pp. doi:10.1029/2010GL043714

Freeman, Mervyn P. , Watkins, Nicholas W., Yoneki, Eiko, Crowcroft, Jon. (2010) Rhythm and randomness in human contact. 2010 International Conference on Advances in Social Networks Analysis and Mining, (). pp. 10.1109/ASONAM.2010.57

2009

Chisham, G. , Freeman, M.P. , Abel, G.A., Bristow, W.A., Marchaudon, A., Ruohoniemi, J.M., Sofko, G.J.. (2009) Spatial distribution of average vorticity in the high-latitude ionosphere and its variation with interplanetary magnetic field direction and season. Journal of Geophysical Research, 114 (). 14 pp. doi:10.1029/2009JA014263

Boakes, P.D., Milan, S.E., Abel, G.A., Freeman, M.P. , Chisham, G. , Hubert, B.. (2009) A statistical study of the open magnetic flux content of the magnetosphere at the time of substorm onset. Geophysical Research Letters, 36 (). 5 pp. doi:10.1029/2008GL037059

Abel, G.A., Freeman, M.P. , Chisham, G. . (2009) IMF clock angle control of multifractality in ionospheric velocity fluctuations. Geophysical Research Letters, 36 (). 5 pp. 10.1029/2009GL040336

Freeman, Mervyn P. , Morley, S. K.. (2009) No evidence for externally triggered substorms based on superposed epoch analysis of IMF Bz. Geophysical Research Letters, 36 (). 4 pp. 10.1029/2009GL040621

Jackman, C.M., Lamy, L., Freeman, Mervyn P. , Zarka, P., Cecconi, B., Kurth, W.S., Cowley, S.W.H., Dougherty, M.K.. (2009) On the character and distribution of lower-frequency radio emissions at Saturn and their relationship to substorm-like events. Journal of Geophysical Research, 114 (). 13 pp. 10.1029/2008JA013997

Morley, S.K., Rouillard, A.P., Freeman, Mervyn P. . (2009) Recurrent substorm activity during the passage of a corotating interaction region. Journal of Atmospheric and Solar-Terrestrial Physics, 71 (). pp. 10.1016/j.jastp.2008.11.009

2008

Alfonsi, Lucilla, Kavanagh, Andrew J., Amata, Ermanno, Cilliers, Pierre, Correia, Emilia, Freeman, Mervyn , Kauristie, Kirsti, Liu, Ruiyuan, Luntama, Juha-Pekka, Mitchell, Cathryn N., Zherebtsov, G.A.. (2008) Probing the high latitude ionosphere from ground-based observations: the state of current knowledge and capabilities during IPY (2007-2009). Journal of Atmospheric and Solar-Terrestrial Physics, 70 (). pp. 10.1016/j.jastp.2008.06.013

Boakes, P.D., Milan, S.E., Abel, G.A., Freeman, M.P. , Chisham, G. , Hubert, B., Sotirelis, T.. (2008) On the use of IMAGE FUV for estimating the latitude of the open/closed magnetic field line boundary in the ionosphere. Annales Geophysicae, 26 (). pp. doi:10.5194/angeo-26-2759-2008

Chisham, G. , Freeman, M.P. , Abel, G.A., Lam, M. M. , Pinnock, M., Coleman, I. J., Milan, S. E., Lester, M., Bristow, W. A., Greenwald, R. A., Sofko, G. J., Villain, J.-P.. (2008) Remote sensing of the spatial and temporal structure of magnetopause and magnetotail reconnection from the ionosphere. Reviews of Geophysics, 46 (). 27 pp. doi:10.1029/2007RG000223

Petkaki, P., Freeman, M.P. . (2008) Nonlinear dependence of ion-acoustic anomalous resistivity on electron drift velocity. Astrophysical Journal, 686 (). pp. 10.1086/590654

Watkins, Nicholas W., Freeman, Mervyn P. . (2008) Natural complexity. Science, 320 (). pp. 10.1126/science.1151611

2007

Abel, G.A., Freeman, M.P. , Chisham, G. , Watkins, N.W.. (2007) Investigating turbulent structure of ionospheric plasma velocity using the Halley SuperDARN radar. Nonlinear Processes in Geophysics, 14 (). pp. 10.5194/npg-14-799-2007

Morley, S.K., Freeman, M.P. . (2007) On the association between northward turnings of the interplanetary magnetic field and substorm onsets. Geophysical Research Letters, 34 (). 6 pp. doi:10.1029/2006GL028891

Abel, Gary A., Freeman, Mervyn P. , Chisham, Gareth , Watkins, Nicholas W.. (2007) Investigating the turbulent structure of ionospheric plasma velocities on open and closed magnetic field lines. In: Shaikh, Dastgeer, Zank, Gary P. (eds.). Turbulence and nonlinear processes in astrophysical plasmas, Melville, New York, American Institute of Physics, pp. (AIP conference proceedings, ).

Chisham, G. , Lester, M., Milan, S.E., Freeman, M.P. , Bristow, W.A., Grocott, A., McWilliams, K.A., Ruohoniemi, J.M., Yeoman, T.K., Dyson, P.L., Greenwald, R.A., Kikuchi, T., Pinnock, M., Rash, J.P.S., Sato, N., Sofko, G.J., Villain, J.-P., Walker, A.D.M.. (2007) A decade of the Super Dual Auroral Radar Network (SuperDARN): scientific achievements, new techniques and future directions. Surveys in Geophysics, 28 (). pp. doi:10.1007/s10712-007-9017-8

Edwards, Andrew M., Phillips, Richard A., Watkins, Nicholas W., Freeman, Mervyn P. , Murphy, Eugene J, , Afanasyev, Vsevolod, Buldyrev, Sergey V., da Luz, M. G. E., Raposo, E. P., Stanley, H. Eugene, Viswanathan, Gandhimohan M.. (2007) Revisiting Lévy flight search patterns of wandering albatrosses, bumblebees and deer. Nature, 449 (). pp. 10.1038/nature06199

Freeman, Mervyn P. . (2007) Auroral substorm. In: Riffenburgh, B. (eds.). Encyclopedia of the Antarctic, New York, Routledge, pp.

Freeman, Mervyn P. . (2007) Magnetic storm. In: Riffenburgh, B. (eds.). Encyclopedia of the Antarctic, New York, Routledge, pp.

Morley, S.K., Freeman, M.P. , Tanskanen, E.I.. (2007) A comparison of the probability distribution of observed substorm magnitude with that predicted by a minimal substorm model. Annales Geophysicae, 25 (). pp. 10.5194/angeo-25-2427-2007

2006

Abel, G.A., Freeman, M.P. , Chisham, G. . (2006) Spatial structure of ionospheric convection velocities in regions of open and closed magnetic field topology. Geophysical Research Letters, 33 (). 4 pp. doi:10.1029/2006GL027919

Abel, G.A., Freeman, M.P. , Smith, A.J., Reeves, G.D.. (2006) Association of substorm chorus events with drift echoes. Journal of Geophysical Research, 111 (). 8 pp. doi:10.1029/2006JA011860

Petkaki, P., Freeman, M.P. , Kirk, T., Watt, C.E.J., Horne, R.B. . (2006) Anomalous resistivity and the non-linear evolution of the ion-acoustic instability. Journal of Geophysical Research, 111 (). 12 pp. 10.1029/2004JA010793

Petkaki, P., Freeman, M.P. , Walsh, A.P.. (2006) Cluster observations of broadband electromagnetic waves in and around a reconnection region in the Earth’s magnetotail current sheet. Geophysical Research Letters, 33 (). 5 pp. 10.1029/2006GL027066

2005

Coleman, Iain J., Freeman, Mervyn P. . (2005) Fractal reconnection structures on the magnetopause. Geophysical Research Letters, 32 (). 4 pp. doi:10.1029/2004GL021779

Abel, G.A., Freeman, M.P. , Chisham, G. . (2005) Comment on “Location of the reconnection line for northward interplanetary magnetic field” by K. J. Trattner, S. A. Fuselier, and S. M. Petrinec. Journal of Geophysical Research, 110 (). 2 pp. doi:10.1029/2004JA010973

Chisham, G. , Freeman, M.P. , Lam, M.M. , Abel, G.A., Sotirelis, T., Greenwald, R.A., Lester, M.. (2005) A statistical comparison of SuperDARN spectral width boundaries and DMSP particle precipitation boundaries in the afternoon sector ionosphere. Annales Geophysicae, 23 (). pp. 10.5194/angeo-23-3645-2005

Chisham, G. , Freeman, M.P. , Sotirelis, T., Greenwald, R.A.. (2005) The accuracy of using the spectral width boundary measured in off-meridional SuperDARN HF radar beams as a proxy for the open-closed field line boundary. Annales Geophysicae, 23 (). pp. 10.5194/angeo-23-2599-2005

Chisham, G. , Freeman, M.P. , Sotirelis, T., Greenwald, R.A., Lester, M., Villain, J.-P.. (2005) A statistical comparison of SuperDARN spectral width boundaries and DMSP particle precipitation boundaries in the morning sector ionosphere. Annales Geophysicae, 23 (). pp. 10.5194/angeo-23-733-2005

Watkins, Nicholas W., Credgington, Daniel, Hnat, Bogdan, Chapman, Sandra C., Freeman, Mervyn P. , Greenhough, John. (2005) Towards synthesis of solar wind and geomagnetic scaling exponents: a fractional Levy motion model. Space Science Reviews, 121 (). pp. doi:10.1007/s11214-006-4578-2

2004

Chisham, G. , Freeman, M.P. . (2004) An investigation of latitudinal transitions in the SuperDARN Doppler spectral width parameter at different magnetic local times. Annales Geophysicae, 22 (). pp. 10.5194/angeo-22-1187-2004

Chisham, G. , Freeman, M.P. . (2004) A statistical comparison of SuperDARN spectral width boundaries and DMSP particle precipitation boundaries in the nightside ionosphere. Geophysical Research Letters, 31 (). 4 pp. 10.1029/2003GL019074

Chisham, G. , Freeman, M.P. , Coleman, I.J., Pinnock, M., Hairston, M.R., Lester, M., Sofko, G.. (2004) Measuring the dayside reconnection rate during an interval of due northward interplanetary magnetic field. Annales Geophysicae, 22 (). pp. 10.5194/angeo-22-4243-2004

Freeman, M.P. , Chisham, G. . (2004) On the probability distributions of SuperDARN Doppler spectral width measurements inside and outside the cusp. Geophysical Research Letters, 31 (). 4 pp. 10.1029/2004GL020923

Freeman, M.P. , Morley, S.K. . (2004) A minimal substorm model that explains the observed statistical distribution of times between substorms. Geophysical Research Letters, 31 (). 4 pp. 10.1029/2004GL019989

2003

Chisham, G. , Freeman, M.P. . (2003) A technique for accurately determining the cusp-region polar cap boundary using SuperDARN HF radar measurements. Annales Geophysicae, 21 (). pp. 10.5194/angeo-21-983-2003

Clarke, Richard W., Freeman, Mervyn P. , Watkins, Nicholas W.. (2003) Application of computational mechanics to the analysis of natural data: an example in geomagnetism. Physical Review E, 67 (). 15 pp. 10.1103/PhysRevE.67.016203

Coleman, Iain J., Chisham, Gareth , Pinnock, Michael, Freeman, Mervyn P. . (2003) Reply to comment by S.M. Petrinec and S.A. Fuselier on ‘An ionospheric convection signature of antiparallel reconnection’. Journal of Geophysical Research, 108 (). 3 pp. 10.1029/2002JA009568

Farrugia, C.J., Burlaga, L.F., Jordanova, V.K., Freeman, M.P. , Lawrence, G., Matsui, H., Cocheci, C.C., Arnoldy, R.L., Scudder, J.D., Ogilvie, K.W., Lepping, R.P.. (2003) Power to the magnetosphere: May 4, 1998. Advances in Space Research, 31 (). pp. 10.1016/S0273-1177902000891-8

Farrugia, C.J., Jordanova, V.K., Freeman, M.P. , Cocheci, C.C., Arnoldy, R.L., Engebretson, M., Stauning, P., Rostoker, G., Thomsen, M.F., Reeves, G., Yumoto, K.. (2003) Large-scale geomagnetic effects of May 4, 1998. Advances in Space Research, 31 (). pp. 10.1016/S0273-1177(02)00890-6

Freeman, M.P. . (2003) A unified model of the response of ionospheric convection to changes in the interplanetary magnetic field. Journal of Geophysical Research, 108 (). 13 pp. 10.1029/2002JA009385

Petkaki, P., Watt, C.E.J., Horne, R.B. , Freeman, M.P. . (2003) Anomalous resistivity in non-Maxwellian plasmas. Journal of Geophysical Research, 108 (). 11 pp. 10.1029/2003JA010092

Pinnock, M., Chisham, G. , Coleman, I.J., Freeman, M.P. , Hairston, M., Villain, J.-P.. (2003) The location and rate of dayside reconnection during an interval of southward interplanetary magnetic field. Annales Geophysicae, 21 (). pp. 10.5194/angeo-21-1467-2003

Rodger, A.S., Chisham, G. , Coleman, I.J., Freeman, M.P. , Pinnock, M.. (2003) Anti-parallel reconnection at the dayside magnetopause: ionospheric signatures and implications for the low latitude boundary layer. In: Newell, P.T., Onsager, T. (eds.). Earth's low-latitude boundary layer, Washington, D.C., American Geophysical Union, pp. (Geophysical Monograph, ).

2002

Chisham, G. , Coleman, I.J., Freeman, M.P. , Pinnock, M., Lester, M.. (2002) Ionospheric signatures of split reconnection X-lines during conditions of IMF Bz < 0 and |By| ∼ |Bz|: Evidence for the antiparallel merging hypothesis. Journal of Geophysical Research, 107 (). pp. 10.1029/2001JA009124

Abel, G.A., Freeman, M.P. . (2002) A statistical analysis of ionospheric velocity and magnetic field power spectra at the time of pulsed ionospheric flows. Journal of Geophysical Research: Space Physics, 107 (). 12 pp. doi:10.1029/2002JA009402

Freeman, Mervyn P. , Watkins, Nicholas W.. (2002) The heavens in a pile of sand. Science, 298 (). pp. 10.1126/science.1075555

Hnat, B., Chapman, S.C., Rowlands, G., Watkins, N.W., Freeman, M.P. . (2002) Scaling of solar wind epsilon and the AU, AL and AE indices by WIND. Geophysical Research Letters, 29 (). 4 pp. 10.1029/2002GL016054

Smith, A.J., Freeman, M.P. , Hunter, S., Milling, D.K.. (2002) VLF, magnetic bay, and Pi2 substorm signatures at auroral and midlatitude ground stations. Journal of Geophysical Research, 107 (). 14 pp. 10.1029/2002JA009389

Watt, C.E.J., Horne, R.B. , Freeman, M.P. . (2002) Ion-acoustic resistivity in plasmas with similar ion and electron temperatures. Geophysical Research Letters, 29 (). pp. 10.1029/2001GL013451

2001

Coleman, Iain J., Chisham, Gareth , Pinnock, Mike, Freeman, Mervyn P. . (2001) An ionospheric convection signature of antiparallel reconnection. Journal of Geophysical Research, 106 (). pp. 10.1029/2001JA900084

Partamies, Ni., Freeman, M.P. , Kauristie, K.. (2001) On the winding of auroral spirals: Interhemispheric observations and Hallinan’s theory revisited. Journal of Geophysical Research, 106 (). pp. 10.1029/2001JA900093

Horne, Richard B. , Freeman, Mervyn P. . (2001) A new code for electrostatic simulation by numerical integration of the Vlasov and Ampere equations using MacCormack’s method. Journal of Computational Physics, 171 (). pp. 10.1006/jcph.2001.6781

Phan, T.D., Freeman, M.P. , Kistler, L.M., Klecker, B., Haerendel, G., Paschmann, G., Sonnerup, B.U.Ö, Baumjohann, W., Bavassano-Cattaneo, M.B., Carlson, C.W., DiLellis, A.M., Fornacon, K.-H., Frank, L.A., Fujimoto, M., Georgescu, E., Kokubun, S., Moebius, E., Mukai, T., Paterson, W.R., Reme, H.. (2001) Evidence for an extended reconnection line at the dayside magnetopause. Earth Planets Space, 53 (). pp.

Watkins, N.W., Freeman, M.P. , Chapman, S.C, Dendy, R.O. (2001) Testing the SOC hypothesis for the magnetosphere. Journal of Atmospheric and Solar-Terrestrial Physics, 63 (). pp. doi:10.1016/S1364-6826(00)00245-5

Watkins, N.W., Freeman, M.P. , Rhodes, C.S., Rowlands, G.. (2001) Ambiguities in determination of self-affinity in the AE-index time series. Fractals, 9 (). pp. doi:10.1142/S0218348X01001123

Watkins, N.W., Oughton, S., Freeman, M.P. . (2001) What can we infer about the underlying physics from burst distributions observed in an RMHD simulation?. Planetary and Space Science, 49 (). pp. doi:10.1016/S0032-0633(01)00064-2

2000

Freeman, M.P. . (2000) Effect of magnetopause leakage on the lifetime of magnetospheric cavity modes. Journal of Geophysical Research, 105 (). pp. doi:10.1029/1999JA900483

Freeman, M.P. , Watkins, N.W., Riley, D.J.. (2000) Evidence for a solar wind origin of the power law burst lifetime distribution of the AE indices. Geophysical Research Letters, 27 (). pp. doi:10.1029/1999GL010742

Freeman, M.P. , Watkins, N.W., Riley, D.J.. (2000) Power law distributions of burst duration and interburst interval in the solar wind: Turbulence or dissipative self-organized criticality?. Physical Review E, 62 (). pp. doi:10.1103/PhysRevE.62.8794

Smith, A.J., Freeman, M.P. , Hunter, S.. (2000) VLF, magnetic and Pi2 substorm signatures. In: Wilson, A. (eds.). Proceedings of the Fifth International Conference on Substorms, St. Petersburg, Russia, May 2000, , European Space Agency, pp. (European Space Agency Special Paper, ).

1999

Freeman, M. P. , Farrugia, C. J.. (1999) Solar wind input between substorm onsets during and after the October 18–20, 1995, magnetic cloud. Journal of Geophysical Research, 104 (). pp. doi:10.1029/1999JA900204

Nishitani, Nozomu, Ogawa, Tadahiko, Pinnock, Mike, Freeman, Mervyn P. , Dudeney, John R., Villain, Jean-Paul, Baker, Kile B., Sato, Natsuo, Yamagishi, Hisao, Matsumoto, Haruhisa. (1999) A very large scale flow burst observed by the SuperDARN radars. Journal of Geophysical Research, 104 (). pp. doi:10.1029/1999JA900241

Smith, A. J., Freeman, M. P. , Wickett, M. G., Cox, B. D.. (1999) On the relationship between the magnetic and VLF signatures of the substorm expansion phase. Journal of Geophysical Research, 104 (). pp. doi:10.1029/1998JA900184

1998

Dudeney, J. R., Rodger, A. S., Freeman, M. P. , Pickett, J., Scudder, J., Sofko, G., Lester, M.. (1998) The nightside ionospheric response to IMF by changes. Geophysical Research Letters, 25 (). pp. doi:10.1029/98GL01413

Farrugia, C. J., Scudder, J. D., Freeman, M. P. , Janoo, L., Lu, G., Quinn, J. M., Arnoldy, R. L., Torbert, R. B., Burlaga, L. F., Ogilvie, K. W., Lepping, R. P., Lazarus, A. J., Steinberg, J. T., Gratton, F. T., Rostoker, G.. (1998) Geoeffectiveness of three Wind magnetic clouds: A comparative study. Journal of Geophysical Research, 103 (). pp. doi:10.1029/98JA00886

Freeman, M. P. , Farrugia, C. J.. (1998) Magnetopause motions in a Newton-Busemann approach. NATO ASI Series. Series C: Mathermatical and physical sciences, 509 (). pp. doi:10.1007/978-94-011-5214-3_2

Lewis, R. V., Freeman, M. P. , Rodger, A. S., Watanabe, M., Greenwald, R. A.. (1998) The behavior of the electric field within the substorm current wedge. Journal of Geophysical Research, 103 (). pp. doi:10.1029/97JA01987

1997

Lewis, R. V., Freeman, M. P. , Rodger, A. S., Reeves, G. D., Milling, D. K.. (1997) The electric field response to the growth phase and expansion phase onset of a small isolated substorm. Annales Geophysicae, 15 (). pp. doi:10.1007/s00585-997-0289-6

1996

Smith, A. J., Freeman, M. P. , Reeves, G. D.. (1996) Post midnight VLF chorus events, a substorm signature observed at the ground nearL= 4. Journal of Geophysical Research: Space Physics, 101 (). pp. doi:10.1029/96JA02236

1995

Freeman, M. P. , Farrugia, C. J.. (1995) A statistical study of the possible effects of solar wind variability on the recurrence rate of substorms. Journal of Geophysical Research, 100 (). pp. doi:10.1029/95JA02688

Freeman, M. P. , Freeman, N. C., Farrugia, C. J.. (1995) A linear perturbation analysis of magnetopause motion in the Newton-Busemann limit. Annales Geophysicae, 13 (). pp. doi:10.1007/s00585-995-0907-0

Morelli, J. P., Bunting, R. J., Cowley, S. W. H., Farrugia, C. J., Freeman, M. P. , Friis-Christensen, E., Jones, G. O. L., Lester, M., Lewis, R. V., Lühr, H., Orr, D., Pinnock, M., Reeves, G. D., Williams, P. J. S., Yeoman, T. K.. (1995) Radar observations of auroral zone flows during a multiple-onset substorm. Annales Geophysicae, 13 (). pp. doi:10.1007/s00585-995-1144-2

Morrison, K., Freeman, M.P. . (1995) The role of upstream ULF waves in the generation of quasi-periodic ELF-VLF emissions. Annales Geophysicae, 13 (). pp. doi:10.1007/s00585-995-1127-3

1994

Yeoman, T.K., Freeman, Mervyn P. , Reeves, G.D., Lester, M., Orr, D.. (1994) A comparison of midlatitude Pi 2 pulsations and geostationary orbit particle injections as substorm indicators. Journal of Geophysical Research, 99 (). pp. 10.1029/93JA03233

Fox, N. J., Lockwood, M., Cowley, S. W. H., Freeman, M. P. , Friis-Christensen, E., Milling, D. K., Pinnock, M., Reeves, G. D.. (1994) EISCAT observations of unusual flows in the morning sector associated with weak substorm activity. Annales Geophysicae, 12 (). pp. doi:10.1007/s00585-994-0541-2

1993

Morelli, J.P., Bunting, R.J., Cowley, S.W.H., Farrugia, C.J., Freeman, M.P. , Friis-Christensen, E., Jones, G.O.L., Lester, M., Lewis, R.V., Luhr, H., Orr, D., Pinnock, M., Reeves, G.D., Williams, P.J.S., Yeoman, T.K.. (1993) Plasma flow bursts in the nightside auroral zone ionosphere and their relation to geomagnetic activity. Advances in Space Research, 13 (). pp. 10.1016/0273-1177(93)90325-6

1992

Cowley, S.W.H., Morelli, J.P., Freeman, M.P. , Lockwood, M., Smith, M.F.. (1992) Excitation and decay of flows in the magnetosphere-ionosphere system due to magnetic reconnection at the dayside magnetopause and in the geomagnetic tail. In: Wilson, A. (eds.). Proceedings of the International Conference on Substorms (ICS-1), Kiruna, Paris, European Space Agency, pp. (ESA special report, ).

Farrugia, C.J., Freeman, Mervyn P. , Burlaga, L.F.. (1992) Magnetic cloud passage at Earth and associated substorm activity. In: Wilson, A. (eds.). Proceedings of the International Conference on Substorms (ICS-1), Kiruna, Paris, European Space Agency, pp. (ESA SP, ).

PRESCIENT
SWIGS
Joule Heating
Space Weather Observatory
THeMES
SuperDARN
The Global Electric Circuit
LPM Network
EISCAT Science Support
A High-Order Model of the Earth’s External and Induced Magnetic Field
SWIMMR-T
Magnetic cloud passage at Earth and associated substorm activity

UKRI Delegate, EISCAT Council
Principal Investigator of BAS low power magnetometer network, SuperMAG Executive Committee
Member, NERC Radar Advisory Group

Research outputs

Mervyn Freeman

Team

Links/Websites

General enquiries

Mervyn Freeman

Biography

Research interests

Collaborations

Publications from NERC Open Research Archive

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