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Data Access
FTPS from SPDF (not with most browsers)
HTTPS from SPDF
CDAWeb
COHOWeb plots and lists
COHOweb top page
WebService:
CDAWeb Programmatic Data Access
HAPI: CDAWeb HAPI Server
Helios 2 hourly merged magnetic field and plasma data
var authors='Ness, Norman F.; Rosenbauer, Helmut R.; Mariani, Franco; Schwenn, Rainer';
document.write(authors);
(2025).
Helios 2 hourly merged magnetic field and plasma data.
[Data set].
Space Physics Data Facility.
https://doi.org/10.48322/509j-gm79. 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/Helios2/MAGandPLS/PT1H
Description
This is an hourly resolution, merged magnetic field and plasma data set created at NSSDC for COHOWeb. Magnetic field vectors and plasma flow direction angles are given in RTN coordinates. Spacecraft position data are given in Heliographic inertial (HGI coordinates).
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/Helios2/MAGandPLS/PT1H
NamingAuthority
NASA
ResourceType
NumericalData
ResourceHeader
ResourceName
Helios 2 hourly merged magnetic field and plasma data
DOI
https://doi.org/10.48322/509j-gm79
ReleaseDate
2026-07-21 12:05:04Z
RevisionHistory
RevisionEvent
ReleaseDate
2021-04-27 15:38:11Z
Note
Only known prior ReleaseDate of the metadata
RevisionEvent
ReleaseDate
2025-09-09 12:34:56.789Z
Note
Revised ObservedRegions. JMW
RevisionEvent
ReleaseDate
2025-11-14 16:02:23Z
Note
Added PublicationInfo. 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 13:29:21Z
Note
Added MetadataRightsList and RightsList(s). Updated to 2.7.1. ZCB
RevisionEvent
ReleaseDate
2026-06-26 13:17:11Z
Note
Add 'Z' to RevisionEvent:ReleaseDate(s), TemporalDescription:TimeSpan:StartDate, TemporalDescription:TimeSpan:StopDate. ZCB
RevisionEvent
ReleaseDate
2026-07-21 12:05:04Z
Note
Added HelioData InformationURL. JWL
Description
This is an hourly resolution, merged magnetic field and plasma data set created at NSSDC for COHOWeb. Magnetic field vectors and plasma flow direction angles are given in RTN coordinates. Spacecraft position data are given in Heliographic inertial (HGI coordinates).
Acknowledgement
Please acknowledge N.F. Ness (P.I.) and F. Mariani for magnetic field data and H. Rosenbauer (P.I.) and R. Schwenn for plasma data, and NSSDC or GSFC-SPDF
PublicationInfo
Authors
Ness, Norman F.; Rosenbauer, Helmut R.; Mariani, Franco; Schwenn, Rainer
PublicationDate
2025-11-14 16:02:23Z
PublishedBy
Space Physics Data Facility
Contacts
Role
Person
StartDate
StopDate
Note
1.
PrincipalInvestigator
spase://SMWG/Person/Norman.F.Ness
2.
PrincipalInvestigator
spase://SMWG/Person/Helmut.R.Rosenbauer
3.
CoInvestigator
spase://SMWG/Person/Franco.Mariani
4.
CoInvestigator
spase://SMWG/Person/Rainer.Schwenn
5.
GeneralContact
spase://SMWG/Person/Natalia.E.Papitashvili
InformationURL
Name
Readme file at SPDF
URL
https://spdf.gsfc.nasa.gov/pub/data/helios/helios2/merged/he2mgd.txt
InformationURL
Name
HelioData
URL
https://helio.data.nasa.gov/dataset/Helios2_MAGandPLS_PT1H
Description
The HelioData dataset page provides an overview of the dataset with access links, associated variables, and more.
PriorIDs
spase://VHO/NumericalData/Helios2/MAGandPLS/PT1H
spase://VSPO/NumericalData/Helios2/MAGandPLS/PT1H
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF
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/helios/helios2/merged/
Description
for annual files via ftp
AccessURL
Name
HTTPS from SPDF
URL
https://spdf.gsfc.nasa.gov/pub/data/helios/helios2/merged/
Description
In CDF via HTTP from SPDF
AccessURL
Name
CDAWeb
URL
https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=HELIOS2_COHO1HR_MERGED_MAG_PLASMA&index=sp_phys
ProductKey
HELIOS2_COHO1HR_MERGED_MAG_PLASMA
Description
For CDAWeb subset,plot and list capabilities
AccessURL
Name
COHOWeb plots and lists
URL
https://omniweb.gsfc.nasa.gov/coho/form/helios2.html
Description
Helios 2-specific page for plots and lists
AccessURL
Name
COHOweb top page
URL
https://omniweb.gsfc.nasa.gov/coho/
Description
Plots, lists, scatter plots, regressions, distributions, means, etc.
Format
Text
AccessDirectoryTemplate
https://cdaweb.gsfc.nasa.gov/pub/data/helios/helios2/coho1hr_magplasma/$Y
AccessFilenameTemplate
helios2_coho1hr_merged_mag_plasma_$Y$m$d_$v.cdf
DataExtent
Quantity
1.2
Units
MB
Per
P1Y
Acknowledgement
Please acknowledge N.F. Ness (P.I.) and F. Mariani for magnetic field data and H. Rosenbauer (P.I.) and R. Schwenn for plasma data, and NSSDC or 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/HELIOS2_COHO1HR_MERGED_MAG_PLASMA/clientLibraryExample/
Style
WebService
ProductKey
HELIOS2_COHO1HR_MERGED_MAG_PLASMA
Description
Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS.
Format
Binary
Acknowledgement
Please acknowledge N.F. Ness (P.I.) and F. Mariani for magnetic field data and H. Rosenbauer (P.I.) and R. Schwenn for plasma data, and NSSDC or GSFC-SPDF
AccessInformation
RepositoryID
spase://SMWG/Repository/NASA/GSFC/SPDF
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
HELIOS2_COHO1HR_MERGED_MAG_PLASMA
Description
Web Service to this product using the HAPI interface.
Format
CSV
Acknowledgement
Please acknowledge N.F. Ness (P.I.) and F. Mariani for magnetic field data and H. Rosenbauer (P.I.) and R. Schwenn for plasma data, and NSSDC or GSFC-SPDF
InstrumentIDs
spase://SMWG/Instrument/Helios2/E1
spase://SMWG/Instrument/Helios2/E3
MeasurementType
MagneticField
MeasurementType
ThermalPlasma
TemporalDescription
TimeSpan
StartDate
1976-01-17 00:00:00Z
StopDate
1980-03-04 00:00:00Z
Cadence
PT1H
ObservedRegion
Heliosphere.Inner
ObservedRegion
Heliosphere
ObservedRegion
Heliosphere.NearEarth
Parameter #1
Name
Year
ParameterKey
Column1
Description
Four digit Year
Cadence
PT1H
FillValue
999.9999
Support
SupportQuantity
Temporal
Parameter #2
Name
Day
ParameterKey
Column2
Description
Decimal Day of Year
Cadence
PT1H
FillValue
999.9999
Support
SupportQuantity
Temporal
Parameter #3
Name
Hour
ParameterKey
Column3
Description
Hour
Cadence
PT1H
FillValue
999.9999
Support
SupportQuantity
Temporal
Parameter #4
Name
Carrington Rotation Number
ParameterKey
Column4
Description
Carrington Rotation Number seen by an Earth based observer at the start of the data interval
Cadence
PT1H
FillValue
999.9999
Support
SupportQuantity
Temporal
Parameter #5
Name
H2 radial distance
ParameterKey
Column05
Description
Heliocentric radial distance of Helios 2 in AU
Cadence
PT1H
Units
AU
Support
SupportQuantity
Positional
Parameter #6
Name
H2 latitude
ParameterKey
Column06
Description
Heliographic Inertial elevation angle of Helios 2 in deg
Cadence
PT1H
Units
deg
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
HGI
Support
SupportQuantity
Positional
Parameter #7
Name
H2 longitude
ParameterKey
Column07
Description
Heliographic Inertial azimuthal angle of Helios 2 in deg
Cadence
PT1H
Units
deg
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
HGI
Support
SupportQuantity
Positional
Parameter #8
Name
ESS angle
ParameterKey
Column08
Description
Earth-Sun-Spacecraft separation angle
Cadence
PT1H
Units
deg
Support
SupportQuantity
Positional
Parameter #9
Name
Magnetic Field Vector, SSE
Description
Hourly averages of SSE (spacecraft-centric solar ecliptic) components of fine time scale magnetic field vectors
Cadence
PT1H
Units
nT
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
SSE
Structure
Size
3
Description
X,Y,Z components
Element
Name
X component
Qualifier
Component.I
Index
1
ParameterKey
Column09
Element
Name
Y component
Qualifier
Component.J
Index
2
ParameterKey
Column10
Element
Name
Z component
Qualifier
Component.K
Index
3
ParameterKey
Column11
FillValue
99999.99
Field
Qualifier
Vector
FieldQuantity
Magnetic
Parameter #10
Name
Magnetic Field Vector, RTN
Description
Hourly averages of RTN components of fine time scale magnetic field vectors
Cadence
PT1H
Units
nT
CoordinateSystem
CoordinateRepresentation
Cartesian
CoordinateSystemName
RTN
Structure
Size
3
Description
R,T,N components
Element
Name
R component
Qualifier
Component.I
Index
1
ParameterKey
Column12
Element
Name
T component
Qualifier
Component.J
Index
2
ParameterKey
Column13
Element
Name
N component
Qualifier
Component.K
Index
3
ParameterKey
Column14
FillValue
99999.99
Field
Qualifier
Vector
FieldQuantity
Magnetic
Parameter #11
Name
Magnetic Field Magnitude
ParameterKey
Column15
Description
Hourly average of fine time scale magnetic field magnitudes
Cadence
PT1H
Units
nT
FillValue
99999.99
Field
Qualifier
Magnitude
FieldQuantity
Magnetic
Parameter #12
Name
Flow speed
ParameterKey
Column16
Description
Hourly averaged solar wind plasma flow speed
Cadence
PT1H
Units
km/s
FillValue
9999.9
Particle
ParticleType
Proton
Qualifier
Average
ParticleQuantity
FlowSpeed
Parameter #13
Name
Flow elevation angle
ParameterKey
Column17
Description
Hourly averaged solar wind plasma flow elevation angle
Cadence
PT1H
Units
deg
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
RTN
FillValue
9999.9
Particle
ParticleType
Proton
Qualifier
DirectionAngle.ElevationAngle
ParticleQuantity
FlowVelocity
Parameter #14
Name
Flow azimuth angle
ParameterKey
Column18
Description
Hourly averaged solar wind plasma flow azimuthal angle
Cadence
PT1H
CoordinateSystem
CoordinateRepresentation
Spherical
CoordinateSystemName
RTN
FillValue
9999.9
Particle
ParticleType
Proton
Qualifier
DirectionAngle.AzimuthAngle
ParticleQuantity
FlowVelocity
Parameter #15
Name
Density
ParameterKey
Column19
Description
Hourly averaged solar wind plasma density
Cadence
PT1H
Units
n/cc
FillValue
999.9
Particle
ParticleType
Proton
Qualifier
Average
ParticleQuantity
NumberDensity
Parameter #16
Name
Temperature
ParameterKey
Column20
Description
Hourly averaged solar wind plasma temperature (radial component)
Cadence
PT1H
Units
degK
FillValue
9999999.
Particle
ParticleType
Proton
Qualifier
Average
ParticleQuantity
Temperature