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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
Polar Cap (PC), Northern and Southern Hemisphere Activity Indices, 5 min Data
var authors='Troshichev, Oleg A.';
document.write(authors);
(2025).
Polar Cap (PC), Northern and Southern Hemisphere Activity Indices, 5 min Data.
[Data set].
Space Physics Data Facility.
https://doi.org/10.48322/vdm3-4236. Accessed on document.write(currentDateStr);.
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ResourceID
spase://NASA/NumericalData/Interball/PC_Index/KeyParameter/K0/PT5M
Description
The PC Index is an Empirical Magnetic Activity Index based on Data from Single Near-Pole Station, Thule for the Northern Hemisphere and Vostok for the Southern Hemisphere, respectively). Its Derivation Procedure is optimized to achieve the Best Correlation of PC Index with the Solar Wind Electric Field, SWEF, Magnitude quantified by v*B*sin((theta/2)^2). The Average Horizontal Magnetic Disturbance Vector, Quiet Value subtracted, is projected onto the Optimal Direction, which is defined empirically for each UT Hour and each Season based on the Best COrrelation with the SWEF. After Normalization to the Equivalent Value of the SWEF, the PC Index is expressed in Units of mV/m. Although the PC Index is formally expressed in mV/m, it actually represents the Measure of Magnetic Activity, the Normalization Procedure to SWEF helps to reduce Seasonal and Diurnal Effects to facilitate the Intercomparison. The Time Resolution of the Northern Cap PC Index is 5 min while it is 15 min form the Southern PC Index. However, one Time SCale with a 5 min Step is used for both Indices and each 15 min averaged Value of southern index is, hence, repeated three Times. References: 1. Troshichev, O.A., et al., Planet. Space Sci., 36, 1095, 1988, 2. Vennerstrom, S., et al., Report UAG-103, World Data Center A for STP, Boulder, April 1994.
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/Interball/PC_Index/KeyParameter/K0/PT5M
NamingAuthority
NASA
ResourceType
NumericalData
ResourceHeader
ResourceName
Polar Cap (PC), Northern and Southern Hemisphere Activity Indices, 5 min Data
DOI
https://doi.org/10.48322/vdm3-4236
ReleaseDate
2025-12-04 13:29:35Z
RevisionHistory
RevisionEvent
ReleaseDate
2021-04-27 15:38:11Z
Note
Only known prior ReleaseDate of the metadata
RevisionEvent
ReleaseDate
2025-11-14 16:02:25Z
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 13:29:35Z
Note
Added MetadataRightsList and RightsList(s). Updated to 2.7.1. ZCB
Description
The PC Index is an Empirical Magnetic Activity Index based on Data from Single Near-Pole Station, Thule for the Northern Hemisphere and Vostok for the Southern Hemisphere, respectively). Its Derivation Procedure is optimized to achieve the Best Correlation of PC Index with the Solar Wind Electric Field, SWEF, Magnitude quantified by v*B*sin((theta/2)^2). The Average Horizontal Magnetic Disturbance Vector, Quiet Value subtracted, is projected onto the Optimal Direction, which is defined empirically for each UT Hour and each Season based on the Best COrrelation with the SWEF. After Normalization to the Equivalent Value of the SWEF, the PC Index is expressed in Units of mV/m. Although the PC Index is formally expressed in mV/m, it actually represents the Measure of Magnetic Activity, the Normalization Procedure to SWEF helps to reduce Seasonal and Diurnal Effects to facilitate the Intercomparison. The Time Resolution of the Northern Cap PC Index is 5 min while it is 15 min form the Southern PC Index. However, one Time SCale with a 5 min Step is used for both Indices and each 15 min averaged Value of southern index is, hence, repeated three Times. References: 1. Troshichev, O.A., et al., Planet. Space Sci., 36, 1095, 1988, 2. Vennerstrom, S., et al., Report UAG-103, World Data Center A for STP, Boulder, April 1994.
Acknowledgement
O.A. Troshichev
PublicationInfo
Authors
Troshichev, Oleg A.
PublicationDate
2025-11-14 16:02:25Z
PublishedBy
Space Physics Data Facility
Contacts
Role
Person
StartDate
StopDate
Note
1.
PrincipalInvestigator
spase://SMWG/Person/Oleg.A.Troshichev
2.
MetadataContact
spase://SMWG/Person/Robert.E.McGuire
3.
MetadataContact
spase://SMWG/Person/Lee.Frost.Bargatze
PriorIDs
spase://VSPO/NumericalData/Interball/PC_Index/KeyParameter/K0/PT5M
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/interball/ground/geo_index/
Description
Access to Data in CDF Format via ftp from SPDF
AccessURL
Name
HTTPS from SPDF
URL
https://spdf.gsfc.nasa.gov/pub/data/interball/ground/geo_index/
Description
Access to Data in CDF Format via http from SPDF
AccessURL
Name
CDAWeb
URL
https://cdaweb.gsfc.nasa.gov/cgi-bin/eval2.cgi?dataset=IG_K0_PCI&index=sp_phys
ProductKey
IG_K0_PCI
Description
Access to ASCII, CDF, and plots via NASA/GSFC CDAWeb
Format
CDF
Encoding
None
AccessDirectoryTemplate
https://cdaweb.gsfc.nasa.gov/pub/data/interball/ground/geo_index/$Y
AccessFilenameTemplate
ig_k0_pci_$Y$m$d_$v.cdf
Acknowledgement
O.A. Troshichev. Please acknowledge the data providers and CDAWeb when using these data.
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/IG_K0_PCI/clientLibraryExample/
Style
WebService
ProductKey
IG_K0_PCI
Description
Access to this data from common programming environments. Note: this AccessInformation element was added by HDPWS.
Format
Binary
Acknowledgement
O.A. Troshichev. Please acknowledge the data providers and CDAWeb when using these data.
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
IG_K0_PCI
Description
Web Service to this product using the HAPI interface.
Format
CSV
Acknowledgement
O.A. Troshichev. Please acknowledge the data providers and CDAWeb when using these data.
ProcessingLevel
Calibrated
InstrumentIDs
spase://SMWG/Instrument/Ground/Thule.Air.Base/Magnetometer
spase://SMWG/Instrument/Ground/Vostok/Magnetometer
MeasurementType
ActivityIndex
TemporalDescription
TimeSpan
StartDate
1995-08-07 00:02:30
StopDate
2000-10-22 23:57:30
Cadence
PT5M
ObservedRegion
Earth.NearSurface.PolarCap
Parameter #1
Name
Epoch Time, Centered
ParameterKey
Epoch
Description
Epoch Time, Centered
Caveats
This parameter exhibits an increasing monotonic progression.
Cadence
PT5M
Units
ms
UnitsConversion
1e-3>s
RenderingHints
AxisLabel
Epoch
ScaleMin
6.2974951569904e+13
ScaleMax
6.2975556069904e+13
ValidMin
01-Jan-1994 00:00:00.000
ValidMax
31-Dec-2020 23:59:59.000
FillValue
-1.0e+31
Support
SupportQuantity
Temporal
Parameter #2
Name
Southern PC Index, PCS, Vostok
Set
Time series defined by using: EPOCH
ParameterKey
PC_Vostok
Description
Southern Polar Cap Magnetic Activity Index, PCS, Vostok
Caveats
15 min averaged value of southern index is repeated for three times.
Cadence
PT5M
Units
mV/m
UnitsConversion
1e-3>V/m
RenderingHints
DisplayType
TimeSeries
AxisLabel
PCS
ValueFormat
F5.1
ScaleMin
-5.0
ScaleMax
15.0
ValidMin
-10.0
ValidMax
30.0
FillValue
-1.0e+31
Field
FieldQuantity
Electric
Parameter #3
Name
Northern PC Index, PCN, Thule
Set
Time series defined by using: EPOCH
ParameterKey
PC_Thule
Description
Northern Polar Cap Magnetic Activity Index, PCN, Thule
Caveats
5 min. resolution
Cadence
PT5M
Units
mV/m
UnitsConversion
1e-3>V/m
RenderingHints
DisplayType
TimeSeries
AxisLabel
PCN
ValueFormat
F5.1
ScaleMin
-5.0
ScaleMax
15.0
ValidMin
-10.0
ValidMax
30.0
FillValue
-1.0e+31
Field
FieldQuantity
Electric
Parameter #4
Name
Status Flag, PCS
Set
Time series defined by using: EPOCH
ParameterKey
Flag_Vostok
Description
Status Flag, PCS: 0=Good Data, 2=Missing Data, 5=Data Delayed
Caveats
Average Type: none
Cadence
PT5M
RenderingHints
AxisLabel
FLag_S
ValueFormat
I2
ScaleMin
0
ScaleMax
5
ValidMin
0
ValidMax
5
FillValue
128
Support
SupportQuantity
InstrumentMode
Parameter #5
Name
Status Flag, PCN
Set
Time series defined by using: EPOCH
ParameterKey
Flag_Thule
Description
Status Flag, PCN: 0=Good Data, 2=Missing Data, 5=Data Delayed
Caveats
Average Type: none
Cadence
PT5M
RenderingHints
AxisLabel
Flag_N
ValueFormat
I2
ScaleMin
0
ScaleMax
5
ValidMin
0
ValidMax
5
FillValue
128
Support
SupportQuantity
InstrumentMode
Parameter #6
Name
Post Gap Flag
Set
Time series defined by using: EPOCH
ParameterKey
Gap_Flag
Description
Post Gap Flag: 0=No Gap before this Point, Values 1 to 5 denote Specific Gap Types
Caveats
Average Type: none
Cadence
PT5M
RenderingHints
AxisLabel
GAP_FLAG
ValueFormat
I1
ScaleMin
0
ScaleMax
5
ValidMin
0
ValidMax
5
FillValue
-2147483648
Support
SupportQuantity
InstrumentMode