5586a319-fa57-4bb6-af3a-3746cd643c0d eng utf8 dataset dataset NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom polardatacentre@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact 2026-01-09 ISO 19115 Geographic Information - Metadata ISO 19115:2003(E) European Petroleum Survey Group (EPSG) Geodetic Parameter Registry 2008-11-12 publication European Petroleum Survey Group EPSGadministrator@iogp.org https://www.epsg-registry.org/ EPSG Geodetic Parameter Dataset The EPSG Geodetic Parameter Dataset is a structured dataset of Coordinate Reference Systems and Coordinate Transformations, accessible through this online registry. information publisher urn:ogc:def:crs:EPSG::3031 6.18.3 Global morphology of chorus waves in the outer radiation belt and the effect of geomagnetic activity and fpe/fce 2026-01-09 creation 2026-01-09 revision 2026-01-09 publication 2026-01-09 released 1.0 https://doi.org/10.5285/5586a319-fa57-4bb6-af3a-3746cd643c0d doi GB/NERC/BAS/PDC/02134 https://data.bas.ac.uk/ Please cite this item as: Bunting, K., Meredith, N., Bortnik, J., Ma, Q., Matsuura, R., & Shen, X. (2026). Global morphology of chorus waves in the outer radiation belt and the effect of geomagnetic activity and fpe/fce (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/5586a319-fa57-4bb6-af3a-3746cd643c0d Whistler-mode chorus waves play a key role in driving radiation belt dynamics by enabling both acceleration of electrons to relativistic energies as well as their loss into the atmosphere via pitch-angle scattering. The ratio between the electron plasma frequency (fpe) and the electron gyrofrequency (fce) significantly influences the efficiency of these processes, with electron acceleration being most effective during periods of low fpe/fce. In this study, a combined total of approximately 24.5 years of THEMIS wave data are analyzed to show how chorus wave intensity and spatial location vary with relative frequency, geomagnetic activity and fpe/fce. Results demonstrate that the strongest chorus emissions are observed during active conditions. At these times, equatorial chorus at low relative frequencies (flhr<f<0.1fce) is strongest when fpe/fce is high (fpe/fce>10) primarily in the region 5<L*<8, from 22:00-12:00 MLT. In sharp contrast at high relative frequencies (0.5fce<f<0.7fce), the equatorial chorus is strongest when fpe/fce is low (fpefce<6) mainly in the region 4<L*<6 from 21:00-09:00 MLT. At intermediate relative frequencies (0.3fce<f<0.4fce), equatorial chorus is strongest in the region 3.5<L*<8 from 21:00-12:00 MLT. In the off-equatorial region the strongest waves are seen in the frequency range (0.1fce<f<0.3fce) between 5<L*<8 and 06:00-15:00 MLT and again are mostly independent of fpe/fce. We show that the location of the strongest waves can be largely explained in terms of the source electrons being in the required energy range for resonance and the absence of Landau damping and highlight the regions where electron acceleration to relativistic energies is likely to be mostly significant. No credit. completed Bunting, Kaine British Antarctic Survey Researcher author Meredith, Nigel British Antarctic Survey Researcher author Bortnik, Jacob UCLA Space institute Researcher author Ma, Qianli UCLA Researcher author Matsuura, Ryoma UCLA Researcher author Shen, Xiao-Chen Boston University Researcher author NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information pointOfContact asNeeded completed EARTH SCIENCE > Sun-earth Interactions > Ionosphere/Magnetosphere Dynamics > Plasma Waves EARTH SCIENCE > Sun-earth Interactions > Solar Energetic Particle Properties theme Global Change Master Directory (GCMD) Science Keywords 2026-01-27 publication 23 Global Change Data Center, Science and Exploration Directorate, Goddard Space Flight Center (GSFC) National Aeronautics and Space Administration (NASA) Greenbelt MD United States of America https://earthdata.nasa.gov/about/gcmd/global-change-master-directory-gcmd-keywords Global Change Master Directory (GCMD) Keywords The information provided on this page seeks to define how the GCMD Keywords are structured, used and accessed. It also provides information on how users can participate in the further development of the keywords. information publisher Radiation belts Wave-particle interaction Whistler-mode chorus theme Global place Atmospheric conditions theme GEMET - INSPIRE themes, version 1.0 2021-01-06 revision otherRestrictions no limitations to public access otherRestrictions no limitations license This dataset is supplied under the Open Government Licence v3.0: https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ url url crossReference textTable eng utf8 geoscientificInformation -180.0 180.0 -90.0 90.0 It is recommended that careful attention be paid to the contents of any data, and that the author be contacted with any questions regarding appropriate use. If you find any errors or omissions, please report them to polardatacentre@bas.ac.uk. NERC EDS UK Polar Data Centre +44 (0)1223 221400 British Antarctic Survey, High Cross, Madingley Road Cambridge Cambridgeshire CB3 0ET United Kingdom PDCServiceDesk@bas.ac.uk https://www.bas.ac.uk/team/business-teams/information-services/uk-polar-data-centre/ information distributor bytes 1 http://ramadda.data.bas.ac.uk/repository/entry/show?entryid=5586a319-fa57-4bb6-af3a-3746cd643c0d WWW:LINK-1.0-http--link Get Data Download data download dataset Methodology: The data used in this study were collected by the NASA Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft. Specifically, we primarily use magnetic (fff) wave data. This data is publicly available at http://themis.ssl.berkeley edu/data/themis. Full details of the subsequent analysis are given in Bunting et al. (2025) Data collection: THEMIS data is used from the THEMIS -A, -D and -E satellites. THEMIS high resolution (fff) data is the fast Fourier transform of magnetic variations observed by the search coil magnetometer on board. The Fluxgate magnetometer gives the background magnetic field strength. Data quality: THEMIS data have been calibrated and quality-controlled prior to release. asNeeded completed