2.7.1 https://spdx.org/licenses/ SPDX CC0-1.0 https://spdx.org/licenses/CC0-1.0.html Creative Commons Zero v1.0 Universal CC0 1.0 Universal is the Creative Commons license applicable to all publicly available SPASE metadata descriptions spase://NASA/NumericalData/ISIS2/IMS/Plasma_Data NASA NumericalData ISIS 2/IMS/Plasma Data https://doi.org/10.48322/8j95-et16 2026-02-12T23:08:28Z 2020-07-07T21:14:42Z Only known prior ReleaseDate of the metadata 2025-11-14T16:02:28Z Added PublicationInfo. Added ResourceType and NamingAuthority. ZCB 2025-12-04T13:29:41Z Added MetadataRightsList and RightsList(s). Updated to 2.7.1. ZCB 2026-02-12T23:08:28Z Added DOI. tlk This set of plasma data came from the ISIS 2 (International Satellites for Ionospheric Studies) ion-mass spectrometer experiment. Ion densities of various ion species are available for the lower range (1-8 atomic mass units, H+, D+, He+, N++, O++) and the upper range (8-64 atomic mass units, O++, N+, O+, 18+, N2+, NO+, O2+). Also included in the data set are spacecraft position data, geomagnetic field intensity, F107 flux (daily solar radio flux), Kp indices, and Dst indices. Hoffman, John H. 2025-11-14T16:02:28Z Space Physics Data Facility spase://SMWG/Person/John.H.Hoffman PrincipalInvestigator spase://VSPO/NumericalData/ISIS2/IMS/Plasma_Data spase://SMWG/Repository/NASA/GSFC/SPDF Online Open https://spdx.org/licenses/ SPDX CC0-1.0 https://spdx.org/licenses/CC0-1.0.html Creative Commons Zero v1.0 Universal CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products FTPS from SPDF (not with most browsers) ftps://spdf.gsfc.nasa.gov/pub/data/isis/ion-mass_spectrometer_ascii_binary/ HTTPS from SPDF https://spdf.gsfc.nasa.gov/pub/data/isis/ion-mass_spectrometer_ascii_binary/ Text spase://SMWG/Instrument/ISIS2/IMS IonComposition 1971-04-21T00:12:41 1972-12-31T23:20:43 Earth.NearSurface.Ionosphere