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Kp, Sum_Kp, ap and Ap Geomagnetic Indices

ResourceID
spase://GBO/NumericalData/Indices/Kp.Ap

Description
Kp, Sum_Kp, (3-hour) ap, and (Daily) Ap geomagnetic indices. Kp and ap are 3-hour planetary indices and Sum_Kp and Ap are daily summed and averaged (respectively) indices created from Kp. These indices were created at the Geophysical Institute of Gottingen University through 1996, and at GeoForschungsZentrum (GFZ, Potsdam) subsequently. GFZ, url given below, is the primary distribution site. The web site of WDC for Geomagnetism at Kyoto U., url given below, offers plots and numeric downloads for Kp and related indices. The data are currently (as of 12/07/2011) "final" from January, 1957, through December, 2008, and are "real time" thereafter, through the current day. Alternative sources of many of the Kp and related indices include the hourly OMNI data set at NASA/GSFC/SPDF. Worldwide Indices The subscript p means planetary and designates a global magnetic activity index. The following 13 observatories, which lie between 46 and 63 degrees north and south geomagnetic latitude, now contribute to the planetary indices: Lerwick (UK), Eskdalemuir (UK), Hartland (UK), Ottawa (Canada), Fredericksburg (USA), Meanook (Canada), Sitka (USA), Eyrewell (New Zealand), Canberra (Australia), Lovo (Sweden), Brorfelde (Denmark), Wingst and Niemegk (Germany). Three-hour-range Index Kp Kp index derives from Ks indices that isolate solar particle effects on the earth's magnetic field; over a 3-hour period, they classify into disturbance levels the range of variation of the more unsettled horizontal field component. Each activity level relates almost logarithmically to its corresponding disturbance amplitude. Three-hour indices discriminate conservatively between true magnetic field perturbations and the quiet-day variations produced by ionospheric currents. Ks indices range in 28 steps from 0 (quiet) to 9 (greatly disturbed) with fractional parts expressed in thirds of a unit. A Ks-value equal to 27, for example, means 2 and 2/3 or 3-; a Ks-value equal to 30 means 3 and 0/3 or 3 exactly; and a Ks-value equal to 33 means 3 and 1/3 or 3+. The arithmetic mean of the Ks values scaled at the 13 observatories listed above gives Kp. Equivalent Amplitude ap The ap-index ranges from 0 to 400 and represents a Kp-value converted to a linear scale in nT (nanoTesla) - a scale that measures equivalent disturbance amplitude of a station at which K=9 has a lower limit of 400 nT.

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NumericalData

ResourceID
spase://GBO/NumericalData/Indices/Kp.Ap
ResourceHeader
ResourceName
Kp, Sum_Kp, ap and Ap Geomagnetic Indices
ReleaseDate
2020-03-17 12:34:56.789
RevisionHistory
RevisionEvent
ReleaseDate
2020-03-17 12:34:56.789
Note
Updated http URL to https, add one new Access URL and one new Information URL, LFB
Description
Kp, Sum_Kp, (3-hour) ap, and (Daily) Ap geomagnetic indices. Kp and ap are 3-hour planetary indices and Sum_Kp and Ap are daily summed and averaged (respectively) indices created from Kp. These indices were created at the Geophysical Institute of Gottingen University through 1996, and at GeoForschungsZentrum (GFZ, Potsdam) subsequently. GFZ, url given below, is the primary distribution site. The web site of WDC for Geomagnetism at Kyoto U., url given below, offers plots and numeric downloads for Kp and related indices. The data are currently (as of 12/07/2011) "final" from January, 1957, through December, 2008, and are "real time" thereafter, through the current day. Alternative sources of many of the Kp and related indices include the hourly OMNI data set at NASA/GSFC/SPDF. Worldwide Indices The subscript p means planetary and designates a global magnetic activity index. The following 13 observatories, which lie between 46 and 63 degrees north and south geomagnetic latitude, now contribute to the planetary indices: Lerwick (UK), Eskdalemuir (UK), Hartland (UK), Ottawa (Canada), Fredericksburg (USA), Meanook (Canada), Sitka (USA), Eyrewell (New Zealand), Canberra (Australia), Lovo (Sweden), Brorfelde (Denmark), Wingst and Niemegk (Germany). Three-hour-range Index Kp Kp index derives from Ks indices that isolate solar particle effects on the earth's magnetic field; over a 3-hour period, they classify into disturbance levels the range of variation of the more unsettled horizontal field component. Each activity level relates almost logarithmically to its corresponding disturbance amplitude. Three-hour indices discriminate conservatively between true magnetic field perturbations and the quiet-day variations produced by ionospheric currents. Ks indices range in 28 steps from 0 (quiet) to 9 (greatly disturbed) with fractional parts expressed in thirds of a unit. A Ks-value equal to 27, for example, means 2 and 2/3 or 3-; a Ks-value equal to 30 means 3 and 0/3 or 3 exactly; and a Ks-value equal to 33 means 3 and 1/3 or 3+. The arithmetic mean of the Ks values scaled at the 13 observatories listed above gives Kp. Equivalent Amplitude ap The ap-index ranges from 0 to 400 and represents a Kp-value converted to a linear scale in nT (nanoTesla) - a scale that measures equivalent disturbance amplitude of a station at which K=9 has a lower limit of 400 nT.
Acknowledgement
GeoForschungsZentrum (GFZ-Potsdam) for creating Kp and related indices since 1996.
Contacts
Role Person StartDate StopDate Note
1. GeneralContact spase://SMWG/Person/Hans.Joachim.Linthe
InformationURL
Name
Indices of Global Geomagnetic Activity
URL
Description
GFZ's pages about Geomagnetic Indices and data links.
InformationURL
Name
GZF Data Services Geomagnetic Kp index web site
URL
Description
Web site descriing the IAGA-endorsed Kp, ap, Ap, Cp and C9 indices and the International Quiet and Disturbed Days. This site can be reached via DOI: the DOI ‘https://doi.org/10.5880/Kp.0001.
InformationURL
Name
Kp/Ap File Format
URL
Description
Description of the WDC file format for selected Kp-related indices
PriorIDs
spase://VMO/NumericalData/Indices/Kp.Ap
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
GFZ-Potsdam, Kp and ap indices, FTP access
URL
Description
FTP download path of Kp and related indices at GFZ-Potsdam, including index documentation and history files.
Format
Text
Acknowledgement
To GFZ for providing data
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
GFZ-Potsdam, Kp and ap indices, HTTP access
URL
Description
HTTP download path of Kp and ap indices at GFZ-Potsdam.
Format
Text
Acknowledgement
To GFZ for providing data
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
WDC for Geomagnetism at Kyoto University, Kp and ap indices
URL
Description
Multi-option (html forms) access to Kp and related indices at Kyoto.
Format
Text
Acknowledgement
To WDC for Geomagnetism, Kyoto, for providing data
ProviderProcessingLevel
Calibrated
MeasurementType
MagneticField
MeasurementType
ActivityIndex
TemporalDescription
TimeSpan
StartDate
1932-01-01 00:00:00
RelativeStopDate
-P1D
Cadence
PT3H
ObservedRegion
Earth.Surface
Parameter #1
Name
Year
ParameterKey
Columns 1-2
Description
Last two digits of the year
Support
SupportQuantity
Temporal
Parameter #2
Name
Month
ParameterKey
Columns 3-4
Description
Month (1-12)
Support
SupportQuantity
Temporal
Parameter #3
Name
Day
ParameterKey
Columns 5-6
Description
Day (1-31)
Support
SupportQuantity
Temporal
Parameter #4
Name
Bartels Rotation
ParameterKey
Columns 7-10
Description
Bartels solar rotation number - a sequence of 27-day intervals counted continuously from February 8, 1832
Support
SupportQuantity
Temporal
Parameter #5
Name
Day within Bartels Rotation
ParameterKey
Columns 11-12
Description
Number of day within the Bartels 27-day cycle.
Support
SupportQuantity
Temporal
Parameter #6
Name
Kp 0-3 UT
ParameterKey
Columns 13-14
Description
Kp (planetary) 3-hour index for 0-3 UT
ValidMin
0
ValidMax
9
Support
SupportQuantity
Other
Parameter #7
Name
Kp 3-6 UT
ParameterKey
Columns 15-16
Description
Kp (planetary) 3-hour index for 3-6 UT
ValidMin
0
ValidMax
9
Support
SupportQuantity
Other
Parameter #8
Name
Kp 6-9 UT
ParameterKey
Columns 17-18
Description
Kp (planetary) 3-hour index for 6-9 UT
ValidMin
0
ValidMax
9
Support
SupportQuantity
Other
Parameter #9
Name
Kp 9-12 UT
ParameterKey
Columns 19-20
Description
Kp (planetary) 3-hour index for 9-12 UT
ValidMin
0
ValidMax
9
Support
SupportQuantity
Other
Parameter #10
Name
Kp 12-15 UT
ParameterKey
Columns 21-22
Description
Kp (planetary) 3-hour index for 12-15 UT
ValidMin
0
ValidMax
9
Support
SupportQuantity
Other
Parameter #11
Name
Kp 15-18 UT
ParameterKey
Columns 23-24
Description
Kp (planetary) 3-hour index for 15-18 UT
ValidMin
0
ValidMax
9
Support
SupportQuantity
Other
Parameter #12
Name
Kp 18-21 UT
ParameterKey
Columns 25-26
Description
Kp (planetary) 3-hour index for 18-21 UT
ValidMin
0
ValidMax
9
Support
SupportQuantity
Other
Parameter #13
Name
Kp 21-24 UT
ParameterKey
Columns 27-28
Description
Kp (planetary) 3-hour index for 21-24 UT
ValidMin
0
ValidMax
9
Support
SupportQuantity
Other
Parameter #14
Name
Kp_sum
ParameterKey
Columns 29-31
Description
Daily Kp sum of the eight Kp indices for the day expressed to the nearest third of a unit
Support
SupportQuantity
Other
Parameter #15
Name
Ap 0-3 UT
ParameterKey
Columns 32-34
Description
Ap (planetary) 3-hour equivalent amplitude for 0-3 UT
Units
nT
ValidMin
0
ValidMax
400
Support
SupportQuantity
Other
Parameter #16
Name
Ap 3-6 UT
ParameterKey
Columns 35-37
Description
Ap (planetary) 3-hour equivalent amplitude for 3-6 UT
Units
nT
ValidMin
0
ValidMax
400
Support
SupportQuantity
Other
Parameter #17
Name
Ap 6-9 UT
ParameterKey
Columns 38-40
Description
Ap (planetary) 3-hour equivalent amplitude for 6-9 UT
Units
nT
ValidMin
0
ValidMax
400
Support
SupportQuantity
Other
Parameter #18
Name
Ap 9-12 UT
ParameterKey
Columns 41-43
Description
Ap (planetary) 3-hour equivalent amplitude for 9-12 UT
Units
nT
ValidMin
0
ValidMax
400
Support
SupportQuantity
Other
Parameter #19
Name
Ap 12-15 UT
ParameterKey
Columns 44-46
Description
Ap (planetary) 3-hour equivalent amplitude for 12-15 UT
Units
nT
ValidMin
0
ValidMax
400
Support
SupportQuantity
Other
Parameter #20
Name
Ap 15-18 UT
ParameterKey
Columns 47-49
Description
Ap (planetary) 3-hour equivalent amplitude for 15-18 UT
Units
nT
ValidMin
0
ValidMax
400
Support
SupportQuantity
Other
Parameter #21
Name
Ap 18-21 UT
ParameterKey
Columns 50-52
Description
Ap (planetary) 3-hour equivalent amplitude for 18-21 UT
Units
nT
ValidMin
0
ValidMax
400
Support
SupportQuantity
Other
Parameter #22
Name
Ap 21-24 UT
ParameterKey
Columns 53-55
Description
Ap (planetary) 3-hour equivalent amplitude for 21-24 UT
Units
nT
ValidMin
0
ValidMax
400
Support
SupportQuantity
Other
Parameter #23
Name
Ap_daily
ParameterKey
Columns 56-58
Description
Ap (planetary) equivalent daily amplitude - the arithmentic mean of the day's eight Ap values.
Units
nT
ValidMin
0
ValidMax
400
Support
Qualifier
Average
SupportQuantity
Other
Parameter #24
Name
Cp
ParameterKey
Columns 59-61
Description
Cp or Planetary Daily Character Figure - a qualitative estimate of overall level of magnetic activity for the day determined from the sum of the eight ap amplitudes. Cp ranges, in steps of one-tenth, from 0 (quiet) to 2.5 (highly disturbed).
ValidMin
0
ValidMax
2.5
Support
SupportQuantity
Other
Parameter #25
Name
C9
ParameterKey
Column 62
Description
C9 - a conversion of the 0-to-2.5 range of the Cp index to one digit between 0 and 9.
ValidMin
0
ValidMax
9
Support
SupportQuantity
Other
Parameter #26
Name
Sunspot Number
ParameterKey
Columns 63-65
Description
International Sunspot Number. Records contain * Zurich number through December 31, 1980 * International Brussels number thereafter
Support
SupportQuantity
Other
Parameter #27
Name
Ottawa Solar Radio Flux
ParameterKey
Columns 66-70
Description
Ottawa 10.7 cm Solar Radio Flux adjusted to 1 AU - measured at 1700 UT daily. Observations began on February 14, 1947. From that date through December 31, 1973, the fluxes given here do not reflect the revisions Ottawa made in 1966.
Units
10^-22 W/m^2/Hz
Support
SupportQuantity
Other
Parameter #28
Name
Flux Qualifier
ParameterKey
Column 71
Description
Flux qualifier * 0: indicates flux required no adjustment * 1: indicates flux required adjustment for burst in progress at time of measurement * 2: indicates a flux approximated by either interpolation or extrapolation * 3: indicates no observation.
Support
SupportQuantity
Other