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ACE Solar Wind Electron Proton Alpha Monitor (SWEPAM) Suprathermal Electron Pitch Angle 128-Second Level 3 Data

Metadata Updated: September 19, 2025

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.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Created Date August 21, 2025
Metadata Updated Date September 19, 2025

Metadata Source

Harvested from NASA Data.json

Additional Metadata

Resource Type Dataset
Metadata Created Date August 21, 2025
Metadata Updated Date September 19, 2025
Publisher SRL ACE Science Center;ASC
Maintainer
Identifier https://doi.org/10.48322/3fs6-7328
Data Last Modified 2025-09-10
Category Heliophysics
Public Access Level public
Bureau Code 026:00
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 7d6956be-5595-498e-b0de-01d679cfee4c
Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
Harvest Source Title NASA Data.json
Homepage URL https://doi.org/10.48322/3fs6-7328
Program Code 026:000
Source Datajson Identifier True
Source Hash c902a5992cf96bd854472ca3dab2a17cb9e1183cc6c73a8fb306ec7ff3d601bb
Source Schema Version 1.1
Temporal 1997-12-16/1997-12-16

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