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Data Access
FTPS from SPDF (not with most browsers)
HTTPS from SPDF
CDAWeb
WebService:
CDAWeb Programmatic Data Access
HAPI: CDAWeb HAPI Server
ACE Science Center ftp area
ACE Science Center
ACE Magnetic Field 16-Second Level 2 Data
var authors='Smith, C.W., and N.F. Ness';
document.write(authors);
(2022).
ACE Magnetic Field 16-Second Level 2 Data.
[Data set].
Space Physics Data Facility; California Institute of Technology.
https://doi.org/10.48322/e0dc-0h53. Accessed on document.write(currentDateStr);.
Note: Proper references, including
Copy BibTeX Citation
or other formats, should include the "Accessed on date" to identify the version of the resource being cited in a given publication.
ResourceID
spase://NASA/NumericalData/ACE/MAG/L2/PT16S
Description
ACE Magnetometer level 2 data, 16-second averages of field magnitude and GSE and GSM Cartesian components, plus standard deviations, plus ACE location data. 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. The "parameter keys" given below are as used by CDAWeb. One-sec, 4-min, 1-hr, 1-day and 27-day averages are also available via the access paths given below.
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/MAG/L2/PT16S
NamingAuthority
NASA
ResourceType
NumericalData
ResourceHeader
ResourceName
ACE Magnetic Field 16-Second Level 2 Data
DOI
https://doi.org/10.48322/e0dc-0h53
ReleaseDate
2026-07-21 12:03:50Z
RevisionHistory
RevisionEvent
ReleaseDate
2021-04-27 15:38:11Z
Note
Only known prior ReleaseDate of the metadata
RevisionEvent
ReleaseDate
2022-08-19 12:34:56.789Z
Note
Added DOI and PublicationInfo minted by JMW on 20220808, updated three InformationURL URLs, updated the RepositoryID, added Robert M. Candey SPDF MetadataContact, metadata updated to SPASE 2.4.1, reviewed by LFB 20220819
RevisionEvent
ReleaseDate
2025-09-30 14:27:18Z
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 13:28:24Z
Note
Added MetadataRightsList and RightsList(s). Updated to 2.7.1. ZCB
RevisionEvent
ReleaseDate
2026-06-26 13:14:16Z
Note
Add 'Z' to RevisionEvent:ReleaseDate(s), PublicationDate. ZCB
RevisionEvent
ReleaseDate
2026-07-21 12:03:50Z
Note
Added HelioData InformationURL. JWL
Description
ACE Magnetometer level 2 data, 16-second averages of field magnitude and GSE and GSM Cartesian components, plus standard deviations, plus ACE location data. 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. The "parameter keys" given below are as used by CDAWeb. One-sec, 4-min, 1-hr, 1-day and 27-day averages are also available via the access paths given below.
Acknowledgement
Please acknowledge the ACE/MAG instrument team and the ACE Science Center
PublicationInfo
Authors
Smith, C.W., and N.F. Ness
PublicationDate
2022-01-01 00:00:00Z
PublishedBy
Space Physics Data Facility; California Institute of Technology
Contacts
Role
Person
StartDate
StopDate
Note
1.
CoInvestigator
spase://SMWG/Person/Norman.F.Ness
2.
TechnicalContact
spase://SMWG/Person/Charles.W.Smith
3.
MetadataContact
spase://SMWG/Person/Robert.M.Candey
4.
MetadataContact
spase://SMWG/Person/James.M.Weygand
5.
MetadataContact
spase://SMWG/Person/Lee.Frost.Bargatze
InformationURL
Name
ACE Magnetometer (MAG) Level 2 data Home Page
URL
https://izw1.caltech.edu/ACE/ASC/level2/mag_l2desc.html
Description
ACE Science Center site hosting instrument information, data release notes, as well as web utilities for plotting and downloading data
InformationURL
Name
Rules of use, and caveats
URL
https://izw1.caltech.edu/ACE/ASC/level2/policy_lvl2.html
Description
ACE level 2 data rules of use, and caveats
InformationURL
Name
HelioData
URL
https://helio.data.nasa.gov/dataset/ACE_MAG_L2_PT16S
Description
The HelioData dataset page provides an overview of the dataset with access links, associated variables, and more.
PriorIDs
spase://VHO/NumericalData/ACE/MAG/L2_PT16S
spase://VSPO/NumericalData/ACE/MAG/L2/PT16S
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb
Availability
Online
AccessRights
Open
RightsList
Rights
SchemeURI
https://spdx.org/licenses/
RightsIdentifierScheme
SPDX
RightsIdentifier
CC0-1.0
RightsURI
https://spdx.org/licenses/CC0-1.0.html
RightsName
Creative Commons Zero v1.0 Universal
Note
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products
AccessURL
Name
FTPS from SPDF (not with most browsers)
URL
ftps://spdf.gsfc.nasa.gov/pub/data/ace/mag/level_2_cdaweb/mfi_h0/
Description
In CDF via ftp from CDAWeb
AccessURL
Name
HTTPS from SPDF
URL
https://spdf.gsfc.nasa.gov/pub/data/ace/mag/level_2_cdaweb/mfi_h0/
Description
In CDF via HTTP from SPDF
Format
CDF
Acknowledgement
Please acknowledge the ACE/MAG instrument team, the ACE Science Center, and the CDAWeb team at GSFC/SPDF.
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb
Availability
Online
AccessRights
Open
RightsList
Rights
SchemeURI
https://spdx.org/licenses/
RightsIdentifierScheme
SPDX
RightsIdentifier
CC0-1.0
RightsURI
https://spdx.org/licenses/CC0-1.0.html
RightsName
Creative Commons Zero v1.0 Universal
Note
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products
AccessURL
Name
CDAWeb
URL
https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=AC_H0_MFI&index=sp_phys
ProductKey
AC_H0_MFI
Description
ACE/MAG L2 16-sec data with subset, plot, list functionalities from CDAWeb
Format
Text
AccessDirectoryTemplate
https://cdaweb.gsfc.nasa.gov/pub/data/ace/mag/level_2_cdaweb/mfi_h0/$Y
AccessFilenameTemplate
ac_h0_mfi_$Y$m$d_$v.cdf
Acknowledgement
Please acknowledge the ACE/MAG instrument team, the ACE Science Center, and the CDAWeb team at GSFC/SPDF.
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF
Availability
Online
AccessRights
Open
AccessURL
Name
CDAWeb Programmatic Data Access
URL
https://cdaweb.gsfc.nasa.gov/WS/cdasr/1/dataviews/sp_phys/datasets/AC_H0_MFI/clientLibraryExample/
Style
WebService
ProductKey
AC_H0_MFI
Description
Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS.
Format
Binary
Acknowledgement
Please acknowledge the ACE/MAG instrument team, the ACE Science Center, and the CDAWeb team at GSFC/SPDF.
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF/CDAWeb
Availability
Online
AccessRights
Open
RightsList
Rights
SchemeURI
https://spdx.org/licenses/
RightsIdentifierScheme
SPDX
RightsIdentifier
CC0-1.0
RightsURI
https://spdx.org/licenses/CC0-1.0.html
RightsName
Creative Commons Zero v1.0 Universal
Note
CC0 1.0 Universal is the Creative Commons license applicable to all publicly available NASA Heliophysics data products
AccessURL
Name
CDAWeb HAPI Server
URL
https://cdaweb.gsfc.nasa.gov/hapi
Style
HAPI
ProductKey
AC_H0_MFI
Description
Web Service to this product using the HAPI interface.
Format
CSV
Acknowledgement
Please acknowledge the ACE/MAG instrument team, the ACE Science Center, and the CDAWeb team at GSFC/SPDF.
AccessInformation
RepositoryID
spase://SMWG/Repository/ACE_SC
Availability
Online
AccessRights
Open
AccessURL
Name
ACE Science Center ftp area
URL
ftp://mussel.srl.caltech.edu/pub/ace/level2/mag/
Description
In HDF via ftp from ACE Science Center
Format
HDF
Acknowledgement
Please acknowledge the ACE/MAG instrument team and the ACE Science Center
AccessInformation
RepositoryID
spase://SMWG/Repository/ACE_SC
Availability
Online
AccessRights
Open
AccessURL
Name
ACE Science Center
URL
https://izw1.caltech.edu/ACE/ASC/level2/lvl2DATA_MAG.html
Description
ACE/MAG L2 16-sec data with subset, plot, list functionalities from the ACE Science Center
Format
Text
Acknowledgement
Please acknowledge the ACE/MAG instrument team and the ACE Science Center
ProviderResourceName
ACE MAG Level 2 Data, 16-second averages
ProviderProcessingLevel
Level 2
ProviderVersion
5
InstrumentIDs
spase://SMWG/Instrument/ACE/MAG
MeasurementType
MagneticField
TemporalDescription
TimeSpan
StartDate
1997-09-02 00:00:12Z
RelativeStopDate
-P2M
Cadence
PT16S
ObservedRegion
Heliosphere.NearEarth
Caveats
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.
Parameter #1
Name
Time
ParameterKey
Epoch
Description
Number of milliseconds since CDF_EPOCH: 0000-01-01T00:00:00.000. Timestamp marks beginning of interval
Units
ms
UnitsConversion
1e-3>s
ValidMin
1996-01-01T00:00:00.000Z
ValidMax
2020-01-01T00:00:00.000Z
FillValue
-1.0E31
Support
SupportQuantity
Temporal
Parameter #2
Name
Time PB5
ParameterKey
Time_PB5
Description
Time of observation in year, day of year, and milliseconds. Timestamp marks beginning of interval
Structure
Size
3
Element
Name
Year
Index
1
Units
year
ValidMin
1997
ValidMax
2020
FillValue
-2147483648
Element
Name
Day of year
Index
2
Units
day
ValidMin
1
ValidMax
366
FillValue
-2147483648
Element
Name
Elapsed milliseconds of day
Index
3
Units
msec
ValidMin
0
ValidMax
86401000
FillValue
-2147483648
Support
SupportQuantity
Temporal
Parameter #3
Name
Bmagnitude
ParameterKey
Magnitude
Description
Magnetic field magnitude
Units
nT
UnitsConversion
1e-9>T
ValidMin
0.0
ValidMax
500.0
FillValue
-1.0E31
Field
Qualifier
Average
Qualifier
Magnitude
FieldQuantity
Magnetic
Parameter #4
Name
B GSE
ParameterKey
BGSEc
Description
Magnetic field vector in GSE Cartesian coordinates (16 sec)
Units
nT
UnitsConversion
1e-9>T
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSE
Structure
Size
3
Element
Name
Bx GSE
Qualifier
Component.I
Index
1
ValidMin
-65534.0
ValidMax
65534.0
FillValue
-1.0E31
Element
Name
By GSE
Qualifier
Component.J
Index
2
ValidMin
-65534.0
ValidMax
65534.0
FillValue
-1.0E31
Element
Name
Bz GSE
Qualifier
Component.K
Index
3
ValidMin
-65534.0
ValidMax
65534.0
FillValue
-1.0E31
Field
Qualifier
Vector
Qualifier
Component.I
Qualifier
Component.J
Qualifier
Component.K
FieldQuantity
Magnetic
Parameter #5
Name
B GSM
ParameterKey
BGSM
Description
Magnetic field vector in GSM coordinates (16 sec)
Units
nT
UnitsConversion
1e-9>T
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSM
Structure
Size
3
Element
Name
Bx GSM
Qualifier
Component.I
Index
1
ValidMin
-65534.0
ValidMax
65534.0
FillValue
-1.0E31
Element
Name
By GSM
Qualifier
Component.J
Index
2
ValidMin
-65534.0
ValidMax
65534.0
FillValue
-1.0E31
Element
Name
Bz GSM
Qualifier
Component.K
Index
3
ValidMin
-65534.0
ValidMax
65534.0
FillValue
-1.0E31
Field
Qualifier
Vector
Qualifier
Component.I
Qualifier
Component.J
Qualifier
Component.K
FieldQuantity
Magnetic
Parameter #6
Name
B RMS
ParameterKey
dBrms
Description
RMS of magnetic field magnitude (16 sec period)
Units
nT
UnitsConversion
1e-9>T
ValidMin
0.0
ValidMax
10.0
FillValue
-1.0E31
Field
Qualifier
StandardDeviation
Qualifier
Magnitude
FieldQuantity
Magnetic
Parameter #7
Name
Data Quality Flag
ParameterKey
Q_FLAG
Description
Data Quality Flag: 0 = good; 1 = S/C Maneuver and subsequent high-nutation period (~4 hr) 2 = Bad data/missing data
ValidMin
0
ValidMax
2
FillValue
-2147483648
Support
SupportQuantity
Other
Parameter #8
Name
S/C position in GSE
ParameterKey
SC_pos_GSE
Description
ACE s/c position in GSE coordinates
Units
km
UnitsConversion
1e3>m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSE
Structure
Size
3
Element
Name
X GSE
Qualifier
Component.I
Index
1
ValidMin
-2000000.0
ValidMax
2000000.0
FillValue
-1.0E31
Element
Name
Y GSE
Qualifier
Component.J
Index
2
ValidMin
-2000000.0
ValidMax
2000000.0
FillValue
-1.0E31
Element
Name
Z GSE
Qualifier
Component.K
Index
3
ValidMin
-2000000.0
ValidMax
2000000.0
FillValue
-1.0E31
Support
SupportQuantity
Positional
Parameter #9
Name
S/C position in GSM
ParameterKey
SC_pos_GSM
Description
ACE s/c position in GSM coordinates
Units
km
UnitsConversion
1e3>m
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
GSM
Structure
Size
3
Element
Name
X GSM
Qualifier
Component.I
Index
1
ValidMin
-2000000.0
ValidMax
2000000.0
FillValue
-1.0E31
Element
Name
Y GSM
Qualifier
Component.J
Index
2
ValidMin
-2000000.0
ValidMax
2000000.0
FillValue
-1.0E31
Element
Name
Z GSM
Qualifier
Component.K
Index
3
ValidMin
-2000000.0
ValidMax
2000000.0
FillValue
-1.0E31
Support
SupportQuantity
Positional