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/PT64S NASA NumericalData ACE Solar Wind Electron Proton Alpha Monitor (SWEPAM) 64-Second Level 2 Data https://doi.org/10.48322/tsfn-6v47 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 Solar Wind Ion parameters from ACE/SWEPAM. Level 2 data, 64-second averages. Parameters include proton density, temperature (radial component) and flow speed, flow velocity vector in GSE, GSM and RTN coordinates, and alpha to proton density ratio. ACE position vectors in GSE and GSM are included. The data are accessible via ftp in HDF and CDF from the ACE Science Center and CDAWeb, respectively, and in ASCII format from the value-added interfaces at those sites. Hourly averaged L2 plasma parameters are also available from these access paths. The "parameter keys" given below are as used by CDAWeb. Please acknowledge the ACE/SWEPAM instrument team and the ACE Science Center McComas, D., Skoug, R., Delapp, D., Elliott, H., and Davis, A. 2022-04-27T00:00:00 Space Physics Data Facility; California Institute of Technology spase://SMWG/Person/Ruth.Skoug TechnicalContact spase://SMWG/Person/David.J.McComas PrincipalInvestigator ACE SWEPAM Level 2 data Home Page https://izw1.caltech.edu/ACE/ASC/level2/swepam_l2desc.html ACE Science Center site hosting instrument information, data release notes, as well as web utilities for plotting and downloading data Rules of use, and caveats https://izw1.caltech.edu/ACE/ASC/level2/policy_lvl2.html ACE level 2 data rules of use, and caveats spase://VHO/NumericalData/ACE/SWEPAM/L2_PT64S spase://VSPO/NumericalData/ACE/SWEPAM/L2/PT64S 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_h0/ FTP repository of 64-second ACE SWEPAM data in CDF format at CDAWeb HTTPS from SPDF https://spdf.gsfc.nasa.gov/pub/data/ace/swepam/level_2_cdaweb/swe_h0/ In CDF via HTTP from SPDF CDF Please acknowledge the ACE/SWEPAM instrument team, the ACE Science Center, and the CDAWeb team at GSFC/SPDF. 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 https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=AC_H0_SWE&index=sp_phys AC_H0_SWE ACE/SWEPAM L2 64-sec data with subset, plot, list functionalities from CDAWeb Text https://cdaweb.gsfc.nasa.gov/pub/data/ace/swepam/level_2_cdaweb/swe_h0/$Y ac_h0_swe_$Y$m$d_$v.cdf Please acknowledge the ACE/SWEPAM instrument team, the ACE Science Center, and the CDAWeb team at GSFC/SPDF. 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_H0_SWE/clientLibraryExample/ AC_H0_SWE Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS. Binary Please acknowledge the ACE/SWEPAM instrument team, the ACE Science Center, and the CDAWeb team at GSFC/SPDF. 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_H0_SWE Web Service to this product using the HAPI interface. CSV Please acknowledge the ACE/SWEPAM instrument team, the ACE Science Center, and the CDAWeb team at GSFC/SPDF. spase://SMWG/Repository/ACE_SC Online Open ACE Science Center ftp area ftp://mussel.srl.caltech.edu/pub/ace/level2/swepam/ In HDF via ftp from ACE Science Center HDF Please acknowledge the ACE/SWEPAM instrument team and the ACE Science Center spase://SMWG/Repository/ACE_SC Online Open ACE Science Center https://izw1.caltech.edu/ACE/ASC/level2/lvl2DATA_SWEPAM.html ACE/SWEPAM L2 64-sec data with subset, plot, list functionalities from the ACE Science Center Text Please acknowledge the ACE/SWEPAM instrument team and the ACE Science Center ACE SWEPAM Level 2 Data, 64-second averages Level 2 9 spase://SMWG/Instrument/ACE/SWEPAM ThermalPlasma 1998-02-04T00:00:12Z -P2M PT64S Heliosphere.NearEarth The quality of ACE level 2 data is 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. Time Epoch Number of milliseconds since CDF_EPOCH: 0000-01-01T00:00:00.000. Timestamp marks beginning of interval ms 1e-3>s 1996-01-01T00:00:00.000Z 2020-01-01T00:00:00.000Z -1.0E31 Temporal Time PB5 Time_PB5 Time of observation in year, day of year, and milliseconds. Timestamp marks beginning of interval 3 Year 1 year 1997 2020 -2147483648 Day of year 2 day 1 366 -2147483648 Elapsed milliseconds of day 3 msec 0 86401000 -2147483648 Temporal Proton Number density Np Solar Wind Proton Number Density, scalar Np is the proton number density in units of cm-3, as calculated by integrating the ion distribution function. cm^-3 0.0 200.0 -1.0E31 Proton Moment NumberDensity Solar Wind Proton Speed Vp Solar Wind Bulk Speed Vp is the solar wind proton speed, or more generally just the solar wind (bulk) speed. It is obtained by integrating the ion (proton) distribution function. km/s 0.0 2500.0 -1.0E31 Proton Moment Scalar Velocity Proton Temperature Tpr radial component of the proton temperature 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. Kelvin 1000.0 1100000.0 -1.0E31 Proton Moment Temperature alpha/proton ratio alpha_ratio alpha to proton density ratio Alpha ratio (Na/Np) - is the ratio of the number density of helium++ ions to the number density of protons. 0.0 10.0 -1.0E31 AlphaParticle Proton Ratio NumberDensity Solar Wind Velocity (GSE) V_GSE Solar Wind Velocity in GSE cartesian coordinates, 64-second average Solar Wind Velocity in GSE coords, 64-second average km/s Cartesian GSE 3 VX (GSE) Component.I 1 -2000.0 0.0 -1.0E31 VY (GSE) Component.J 2 -900.0 900.0 -1.0E31 VZ (GSE) Component.K 3 -900.0 900.0 -1.0E31 Proton Moment Vector Velocity Solar Wind Velocity (RTN) V_RTN Solar Wind Velocity in RTN cartesian coordinates, 64-second average Solar Wind Velocity in RTN cartesian coordinates, 64-second average km/s Cartesian RTN 3 VR (RTN) Component.I 1 0.0 2000.0 -1.0E31 VT (RTN) Component.J 2 -900.0 900.0 -1.0E31 VN (RTN) Component.K 3 -900.0 900.0 -1.0E31 Proton Moment Vector Velocity Solar Wind Velocity (GSM) V_GSM Solar Wind Velocity in GSM cartesian coordinates, 64-second average Solar Wind Velocity in GSM ccartesian coordinates, 64-second average km/s Cartesian GSM 3 VX (GSM) Component.I 1 -1800.0 0.0 -1.0E31 VY (GSM) Component.J 2 -900.0 900.0 -1.0E31 VZ (GSM) Component.K 3 -900.0 900.0 -1.0E31 Proton Moment Vector Velocity S/C position in GSE SC_pos_GSE ACE s/c position in GSE coordinates km 1e3>m Cartesian GSE 3 X GSE Component.I 1 -2000000.0 2000000.0 -1.0E31 Y GSE Component.J 2 -2000000.0 2000000.0 -1.0E31 Z GSE Component.J 3 -2000000.0 2000000.0 -1.0E31 Positional S/C position in GSM SC_pos_GSM ACE s/c position in GSM coordinates km 1e3>m Cartesian GSM 3 X GSM Component.I 1 -2000000.0 2000000.0 -1.0E31 Y GSM Component.J 2 -2000000.0 2000000.0 -1.0E31 Z GSM Component.K 3 -2000000.0 2000000.0 -1.0E31 Positional