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Data Access
ACE Science Center Data Set Page
ACE Solar Wind Electron Proton Alpha Monitor (SWEPAM) Suprathermal Electron Pitch Angle 128-Second Level 3 Data
var authors='McComas, D., Skoug, R., Delapp, D., Elliott, H., and Davis, A.';
document.write(authors);
(2022).
ACE Solar Wind Electron Proton Alpha Monitor (SWEPAM) Suprathermal Electron Pitch Angle 128-Second Level 3 Data.
[Data set].
Space Physics Data Facility.
https://doi.org/10.48322/3fs6-7328. Accessed on document.write(currentDateStr);.
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ResourceID
spase://NASA/NumericalData/ACE/SWEPAM/L3/PT128S
Description
Suprathermal Electron Pitch Angle data from ACE/SWEPAM. Level 3 data, 128-second averages. These pitch angle distributions are calculated automatically by a computer code, and have not been validated by a person. It is therefore likely that they include some artifacts and erroneous values. These data files contain suprathermal electron pitch angle distribution functions (s^3 cm^-6) at 272 eV from the ACE/SWEPAM-E instrument. The energy channel is ~12% wide, centered at 272 eV. Pitch angle bins are 9 degrees wide, and run from 0 to 180 degrees (so 0-9, 9-18, 18-27 degrees, etc.). The break between the core and suprathermal electrons is generally around 70 eV at 1 AU, but varies around this value, at times exceeding 100 eV. Electrons at 272 eV are generally well within the suprathermal range, and the distribution at this energy typically shows very little contribution from the core population. The measured count rates at 272 eV energy provide excellent statistical significance. In addition, because of the high count rates, very few artifacts (for example due to sunlight contamination) are seen in the data at this energy. The data are in the solar wind frame, and have been corrected for the spacecraft potential. The spacecraft potential determination requires measurement of the lower energy electrons, and so the potentials calcuated at these times have been interpolated to the times of the suprathermal electron measurements. Transformation to the solar wind frame requires interpolation of the measurements (each at a different energy in the solar wind frame) to the desired energy (272 eV). Also note that the detector gains on the SWEPAM-E instrument change over time, including both slowly decreasing gains and abrupt increases when the instrument voltages are increased. The use of these data for long-term studies of the distribution function amplitudes is therefore strongly discouraged.
Metadata Rights
CC0-1.0:
Creative Commons Zero v1.0 Universal
Note
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available SPASE metadata descriptions. The actual data/software may be subject to a different license.
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Details
Version:2.7.1
NumericalData
ResourceID
spase://NASA/NumericalData/ACE/SWEPAM/L3/PT128S
NamingAuthority
NASA
ResourceType
NumericalData
ResourceHeader
ResourceName
ACE Solar Wind Electron Proton Alpha Monitor (SWEPAM) Suprathermal Electron Pitch Angle 128-Second Level 3 Data
DOI
https://doi.org/10.48322/3fs6-7328
ReleaseDate
2026-06-26 13:14:21Z
RevisionHistory
RevisionEvent
ReleaseDate
2020-07-07 21:14:15Z
Note
Last known prior metadata Release Date
RevisionEvent
ReleaseDate
2022-04-20 12:34:56.789Z
Note
ACE: DOI and PublicationInfo added, metadata revised by J.M. Weygand on 2022-04-08, reviewed by LFB
RevisionEvent
ReleaseDate
2022-05-17 12:34:56.789Z
Note
ACE: Updated to SPASE Version 2.4.0, two InformationURL URLs updated, revised by LFB on 2022-05-17
RevisionEvent
ReleaseDate
2025-09-30 14:27:19Z
Note
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
RevisionEvent
ReleaseDate
2025-12-04 13:28:25Z
Note
Added MetadataRightsList. Updated to 2.7.1. ZCB
RevisionEvent
ReleaseDate
2026-06-26 13:14:21Z
Note
Add 'Z' to RevisionEvent:ReleaseDate(s), PublicationDate. ZCB
Description
Suprathermal Electron Pitch Angle data from ACE/SWEPAM. Level 3 data, 128-second averages. These pitch angle distributions are calculated automatically by a computer code, and have not been validated by a person. It is therefore likely that they include some artifacts and erroneous values. These data files contain suprathermal electron pitch angle distribution functions (s^3 cm^-6) at 272 eV from the ACE/SWEPAM-E instrument. The energy channel is ~12% wide, centered at 272 eV. Pitch angle bins are 9 degrees wide, and run from 0 to 180 degrees (so 0-9, 9-18, 18-27 degrees, etc.). The break between the core and suprathermal electrons is generally around 70 eV at 1 AU, but varies around this value, at times exceeding 100 eV. Electrons at 272 eV are generally well within the suprathermal range, and the distribution at this energy typically shows very little contribution from the core population. The measured count rates at 272 eV energy provide excellent statistical significance. In addition, because of the high count rates, very few artifacts (for example due to sunlight contamination) are seen in the data at this energy. The data are in the solar wind frame, and have been corrected for the spacecraft potential. The spacecraft potential determination requires measurement of the lower energy electrons, and so the potentials calcuated at these times have been interpolated to the times of the suprathermal electron measurements. Transformation to the solar wind frame requires interpolation of the measurements (each at a different energy in the solar wind frame) to the desired energy (272 eV). Also note that the detector gains on the SWEPAM-E instrument change over time, including both slowly decreasing gains and abrupt increases when the instrument voltages are increased. The use of these data for long-term studies of the distribution function amplitudes is therefore strongly discouraged.
Acknowledgement
Please acknowledge the ACE/SWEPAM instrument team and the ACE Science Center
PublicationInfo
Authors
McComas, D., Skoug, R., Delapp, D., Elliott, H., and Davis, A.
PublicationDate
2022-04-27 00:00:00Z
PublishedBy
Space Physics Data Facility
Contacts
Role
Person
StartDate
StopDate
Note
1.
TechnicalContact
spase://SMWG/Person/Andrew.J.Davis
InformationURL
Name
ACE SWEPAM Level 3 Suprathermal Electron Pitch Angle Home Page
URL
https://izw1.caltech.edu/ACE/ASC/DATA/level3/swepam/index.html
Description
ACE Science Center site hosting description of the data set
PriorIDs
spase://VHO/NumericalData/ACE/SWEPAM/L3_PT128S
spase://VSPO/NumericalData/ACE/SWEPAM/L3/PT128S
AccessInformation
RepositoryID
spase://SMWG/Repository/ACE_SC
Availability
Online
AccessRights
Open
AccessURL
Name
ACE Science Center Data Set Page
URL
https://izw1.caltech.edu/ACE/ASC/DATA/level3/swepam/data/
Description
HTTP file listing of the ACE SWEPAM Suprathermal Electron Pitch Angle files available at ACE Science Center
Format
Text.ASCII
Encoding
ZIP
Acknowledgement
Please acknowledge the ACE/SWEPAM instrument team and the ACE Science Center
ProviderResourceName
ACE SWEPAM Suprathermal Electron Pitch Angle Level 3 Data
ProviderProcessingLevel
Level 3
InstrumentIDs
spase://SMWG/Instrument/ACE/SWEPAM
MeasurementType
ThermalPlasma
TemporalDescription
TimeSpan
StartDate
1997-12-16 00:00:00Z
RelativeStopDate
-P12M
Cadence
PT128S
ObservedRegion
Heliosphere.NearEarth
Parameter #1
Name
Year
ParameterKey
Column_1
Description
Year of the data point
Support
SupportQuantity
Temporal
Parameter #2
Name
DOY
ParameterKey
Column_2
Description
Day of year
Support
SupportQuantity
Temporal
Parameter #3
Name
Hour
ParameterKey
Column_3
Description
Hour of the data point
Support
SupportQuantity
Temporal
Parameter #4
Name
Minute
ParameterKey
Column_4
Description
Minute of the data point
Support
SupportQuantity
Temporal
Parameter #5
Name
Second
ParameterKey
Column_5
Description
Second of the data point
Support
SupportQuantity
Temporal
Parameter #6
Name
SCT
ParameterKey
Column_6
Description
Spacecraft Time
Support
SupportQuantity
Temporal
Parameter #7
Name
Suprathermal electron pitch angle distribution functions
ParameterKey
Column_7 thru Column_27
Description
Suprathermal electron pitch angle distribution functions at 272 eV from the ACE/SWEPAM-E instrument. The energy channel is ~12% wide, centered at 272 eV. Pitch angle bins are 9 degrees wide, and run from 0 to 180 degrees (so 0-9, 9-18, 18-27 degrees, etc.).
Units
s^3 cm^-6
Structure
Size
20
Particle
ParticleType
Electron
ParticleQuantity
PhaseSpaceDensity