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/ACE/SWEPAM/L2/PT1H NASA NumericalData ACE Solar Wind Electron, Proton, and Alpha Monitor (SWEPAM) Plasma Moments, Level 2 (H2), 1 h Data https://doi.org/10.48322/9w01-2555 2025-12-04T13:28:25Z 2021-04-27T15:38:11 Last known prior metadata Release Date 2022-04-20T12:34:56.789 ACE: DOI and PublicationInfo added, metadata revised by J.M. Weygand on 2022-04-08, reviewed by LFB 2022-05-17T12:34:56.789 ACE: Updated to SPASE Version 2.4.0, three InformationURL URLs updated, revised by LFB on 2022-05-17 2025-09-30T14:27:19Z Updated PublishedBy name to match ROR Registry. Added ResourceType and NamingAuthority. Changed http to https in top-level schemaLocation attribute. Fixed version number separator in top-level schemaLocation attribute. Matched version number in schemaLocation attribute to updated value in Version tag. ZCB 2025-12-04T13:28:25Z Added MetadataRightsList and RightsList(s). Updated to 2.7.1. ZCB This Data Product contains Measurements from the ACE Solar Wind Electron Proton Alpha Monitor (SWEPAM) Instrument. The Quality of the ACE Level 2 Data are such that it is suitable for serious Scientific Study. However, to avoid Confusion and Misunderstanding, it is recommended that Users consult with the appropriate ACE Team Members before publishing Work derived from the Data. The ACE Team has worked hard to ensure that the Level 2 Data are free from Errors, but the Team cannot accept Responsibility for erroneous Data, or for Misunderstandings about how the Data may be used. This is especially true if the appropriate ACE Team Members are not consulted before Publication. At the very least, Preprints should be forwarded to the ACE Team before Publication. SWEPAM References: https://izw1.caltech.edu/ACE/ D.J. McComas, Please acknowledge the Principal Investigator, D.J. McComas, Southwest Research Institute. See the Rules Of Use available from the ACE Science Center at: http://www.srl.caltech.edu/ace/asc/level2/policy_lvl2.html. McComas, D., Skoug, R., Delapp, D., Elliott, H., and Davis, A. 2022-04-27T00:00:00 Space Physics Data Facility spase://SMWG/Person/David.J.McComas PrincipalInvestigator spase://SMWG/Person/Ruth.Skoug DataProducer spase://SMWG/Person/Robert.E.McGuire MetadataContact spase://SMWG/Person/Lee.Frost.Bargatze MetadataContact ACE Science Center Home Page for Level 2 Data Release Notes https://izw1.caltech.edu/ACE/ASC/level2/index.html ACE Level 2 Data Release Notes Home Page ACE Science Center Home Page for Level 2 Rules of Use https://izw1.caltech.edu/ACE/ASC/level2/policy_lvl2.html ACE Level 2 Rules of Use Home Page ACE SWEPAM Instrument Description https://doi.org/10.1023/A:1005040232597 McComas, D.J., Bame, S.J., Barker, P., Feldman, W.C., Phillips, J.L., Riley, P., and J.W. Griffee, Solar Wind Electron Proton Alpha Monitor (SWEPAM) for the Advanced Composition Explorer, Space Sci. Rev., 86, 563–612, 1998 spase://VSPO/NumericalData/ACE/SWEPAM/L2/PT3600S spase://VSPO/NumericalData/P_ACE_HDR_SWEPAM_1HR spase://VSPO/NumericalData/ACE/SWEPAM/L2/PT1H 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/ace/swepam/level_2_cdaweb/swe_h2/ Access to Data in CDF Format via ftp from SPDF HTTPS from SPDF https://spdf.gsfc.nasa.gov/pub/data/ace/swepam/level_2_cdaweb/swe_h2/ Access to Data in CDF Format via http from SPDF CDAWeb https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=AC_H2_SWE&index=sp_phys AC_H2_SWE Access to ASCII, CDF, and Plots via NASA/GSFC CDAWeb CDF None https://cdaweb.gsfc.nasa.gov/pub/data/ace/swepam/level_2_cdaweb/swe_h2/$Y ac_h2_swe_$Y$m$d_$v.cdf D.J. McComas, Please acknowledge the Principal Investigator, D.J. McComas, Southwest Research Institute. See the Rules Of Use available from the ACE Science Center at: http://www.srl.caltech.edu/ace/asc/level2/policy_lvl2.html. Please acknowledge the Data Providers and CDAWeb when using these Data. spase://SMWG/Repository/NASA/GSFC/SPDF Online Open CDAWeb Programmatic Data Access https://cdaweb.gsfc.nasa.gov/WS/cdasr/1/dataviews/sp_phys/datasets/AC_H2_SWE/clientLibraryExample/ AC_H2_SWE Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS. Binary D.J. McComas, Please acknowledge the Principal Investigator, D.J. McComas, Southwest Research Institute. See the Rules Of Use available from the ACE Science Center at: http://www.srl.caltech.edu/ace/asc/level2/policy_lvl2.html. Please acknowledge the Data Providers and CDAWeb when using these 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 CDAWeb HAPI Server https://cdaweb.gsfc.nasa.gov/hapi AC_H2_SWE Web Service to this product using the HAPI interface. CSV D.J. McComas, Please acknowledge the Principal Investigator, D.J. McComas, Southwest Research Institute. See the Rules Of Use available from the ACE Science Center at: http://www.srl.caltech.edu/ace/asc/level2/policy_lvl2.html. Please acknowledge the Data Providers and CDAWeb when using these Data. Calculated spase://SMWG/Instrument/ACE/Ephemeris spase://SMWG/Instrument/ACE/SWEPAM Ephemeris ThermalPlasma 1998-02-04T00:00:00.000 -P3M The Data become available about three Months after Observation PT1H Heliosphere Heliosphere.Inner Heliosphere.NearEarth Epoch Time Epoch Epoch Time, Beginning of Interval Average Type: standard This Parameter exhibits an increasing Monotonic Progression. PT1H ms 1.0e-3>s Epoch E14.8 6.2987652219904e+13 6.3745034619904e+13 LinearScale 01-Jan-1996 00:00:00.000 01-Jan-2020 00:00:00.000 -1.0e+31 Temporal Time PB5 Time Series defined by using: EPOCH Time_PB5 Time PB5, Time of Observation, Year, Day, and Milliseconds of Day This Parameter exhibits an increasing Monotonic Progression. PT1H LinearScale 3 Year 1 a 1997 2020 year 1997 2020 Day of Year (Jan 1 = Day 1) 2 d 1 366 day 1 366 Elapsed milliseconds of day 3 ms 0 86400 msec 0 86400 -2147483648 Temporal Solar Wind Proton Number Density Time Series defined by using: EPOCH Np Solar Wind Proton Number Density Np is the Solar Wind Proton Number Density in Units of cm^-3, as calculated by Integration of the Ion Distribution Function. PT1H cm^-3 1.0e6>m^-3 TimeSeries H_Density F8.4 0.0 100.0 0.0 200.0 -1.0e+31 Proton Magnitude Moment NumberDensity 1 Solar Wind Proton Bulk Speed Time Series defined by using: EPOCH Vp Solar Wind Proton Bulk Speed Vp is the Solar Wind Proton Speed, or more generally just the Solar Wind Bulk Speed. It is obtained by Integration of the Ion (Proton) Distribution Function. PT1H km/s 1.0e3>m/s TimeSeries SW_H_Speed F8.2 0.0 500.0 0.0 2000.0 -1.0e+31 Proton Moment Scalar FlowSpeed 1 Solar Wind Proton Temperature, Radial Time Series defined by using: EPOCH Tpr Solar Wind Proton Temperature, Radial Component The Radial Component of the Proton Temperature is the (1,1) Component of the Temperature Tensor, along the Radial Direction. It is obtained by Integration of the Ion (Proton) Distribution Function. PT1H °K TimeSeries H_Temp_radial F9.1 1000.0 1.1e+06 1000.0 1.1e+06 -1.0e+31 Proton Component.I Temperature 1 Solar Wind Alpha Particle to Proton Density Ratio Time Series defined by using: EPOCH alpha_ratio Solar Wind Alpha Particle to Proton, He++/H+, Density Ratio Alpha Ratio (Na/Np) is the Ratio of the Number Density of Helium++ Ions to the Number Density of Protons PT1H TimeSeries Na/Np F8.4 0.0 0.5 0.0 10.0 -1.0e+31 AlphaParticle Proton Ratio Scalar NumberDensity 1 2 Solar Wind Bulk Velocity Vector, GSE, Cartesian Coordinates Time Series defined by using: EPOCH V_GSE Solar Wind Bulk Velocity Vector, Geocentric Solar Ecliptic, GSE, Cartesian Coordinates PT1H km/s 1.0e3>m/s Cartesian GSE TimeSeries F8.1 3 VX (GSE) 1 -1800.0 0.0 -1200.0 0.0 VY (GSE) 2 -900.0 900.0 -500.0 500.0 VZ (GSE) 3 -900.0 900.0 -500.0 500.0 -1.0e+31 Ion Vector Moment FlowVelocity Solar Wind Bulk Velocity Vector, RTN, Cartesian Coordinates Time Series defined by using: EPOCH V_RTN Solar Wind Bulk Velocity Vector, Radial Tangential Normal, RTN, Cartesian Coordinates PT1H km/s 1.0e3>m/s Cartesian RTN TimeSeries F8.1 3 VR (RTN) 1 0.0 1800.0 0.0 1200.0 VT (RTN) 2 -900.0 900.0 -500.0 500.0 VN (RTN) 3 -900.0 900.0 -500.0 500.0 -1.0e+31 Ion Vector Moment FlowVelocity Solar Wind Bulk Velocity Vector, GSM, Cartesian Coordinates Time Series defined by using: EPOCH V_GSM Solar Wind Bulk Velocity Vector, Geocentric Solar Magnetospheric, GSM, Cartesian Coordinates PT1H km/s 1.0e3>m/s Cartesian GSM TimeSeries F8.1 3 VX (GSM) 1 -1800.0 0.0 -1200.0 0.0 VY (GSM) 2 -900.0 900.0 -500.0 500.0 VZ (GSM) 3 -900.0 900.0 -500.0 500.0 -1.0e+31 Ion Vector Moment FlowVelocity Spacecraft Position Vector, GSE, Cartesian Coordinates Time Series defined by using: EPOCH SC_pos_GSE Spacecraft Position Vector, Geocentric Solar Ecliptic, GSE, Cartesian Coordinates Average Type: standard PT1H km 1.0e3>m Cartesian GSE TimeSeries F9.1 3 ACE X-GSE 1 -2.0e+06 2.0e+06 -2.0e+06 2.0e+06 ACE Y-GSE 2 -1.0e+06 1.0e+06 -1.0e+06 1.0e+06 ACE Z-GSE 3 -1.0e+06 1.0e+06 -1.0e+06 1.0e+06 -1.0e+31 Vector Positional Spacecraft Position Vector, GSM, Cartesian Coordinates Time Series defined by using: EPOCH SC_pos_GSM Spacecraft Position Vector, Geocentric Solar Magnetospheric, GSM, Cartesian Coordinates Average Type: standard PT1H km 1.0e3>m Cartesian GSM TimeSeries F9.1 3 ACE X(GSM) 1 -2.0e+06 2.0e+06 -2.0e+06 2.0e+06 ACE Y(GSM) 2 -1.0e+06 1.0e+06 -1.0e+06 1.0e+06 ACE Z(GSM) 3 -1.0e+06 1.0e+06 -1.0e+06 1.0e+06 -1.0e+31 Vector Positional