Space Weather Data Documentation

Updated 2023 May 26

CelesTrak has switched to using primary sources, wherever available, for producing the Space Weather Data, to mitigate the introduction of errors and inconsistencies found in some secondary sources. Users should expect to see differences in the data as a result of these improvements.

In addition to the legacy fixed-field format, the data is now also available in CSV format, to facilitate easier input to spreadsheets and other tools which support this standard. The CSV and legacy fixed-field formats are described below.

• Data used:

  1. Geomagnetic data

     https://www-app3.gfz-potsdam.de/kp_index/Kp_ap_Ap_SN_F107_since_1932.txt

     Nowcast data

     https://www-app3.gfz-potsdam.de/kp_index/Kp_ap_Ap_SN_F107_nowcast.txt

     Contains: BSRN, ND, 3-hourly K_p, 3-hourly a_p, and A_p. C_p and C₉ are calculated based on information originally available from http://wwwuser.gwdg.de/~rhennin/ap.html and https://ccmc.gsfc.nasa.gov/modelweb/solar/ap.html (these links no longer work).
     That information can now be found at:

     https://spaceweather.gfz-potsdam.de/products-data/nowcasts/nowcast-kp-index/geomagnetic-indices-ap-ap-cp-and-c9-derivative-indices

     Format documentation: Included in the header of the data.

     Nowcast data for the current date is merged into the NOAA SWPC 45-day predictions below.

     Updated: Current to the current date.

  2. International Sunspot Number

     https://www.sidc.be/SILSO/DATA/SN_d_tot_V2.0.txt (Daily)
     https://www.sidc.be/SILSO/DATA/EISN/EISN_current.txt (Daily Estimated)

     Contains: ISN

     Format documentation: https://www.sidc.be/SILSO/infosndtot (Daily), https://www.sidc.be/SILSO/eisninfo (Daily Estimated)

     Updated: Current to within the past month.

  3. 10.7-cm Solar Radio Flux (F10.7) data

     https://spaceweather.gc.ca/solar_flux_data/daily_flux_values/F107_1947_1996.txt (1947–1996)
     https://spaceweather.gc.ca/solar_flux_data/daily_flux_values/F107_1996_2007.txt (1996–2007)
     https://spaceweather.gc.ca/solar_flux_data/daily_flux_values/fluxtable.txt (2004–Present)

     Contains: F10.7_Obs, F10.7_Adj

     Format documentation: https://www.spaceweather.gc.ca/forecast-prevision/solar-solaire/solarflux/sx-3-en.php

     Updated: Current to current date.

  4. 3-Hourly K_p Predictions

     https://services.swpc.noaa.gov/products/noaa-planetary-k-index-forecast.json

     Contains: 3-hourly forecast of daily K_p for the coming 3 days. The K_p data is used to calcuate the a_p, C_p, and C₉ data. It is used from the end of the GFZ nowcast and followed by the 45-day predictions below.

     Updated: Every 3 hours

  5. 45-Day Predictions

     https://services.swpc.noaa.gov/text/45-day-ap-forecast.txt

     Contains: 45-day forecast of daily a_p and F10.7_Adj. K_p is estimated from a_p and F10.7_Obs is calculated from F10.7_Adj.

     Updated: Daily

  6. Monthly Sunspot Predictions

     https://www.nasa.gov/wp-content/uploads/2024/09/sep2024ssn-prd.txt

     Contains: Monthly ISN for approximately 18.5 years. The 50th-percentile values are used.

     Format documentation: https://www.nasa.gov/solar-cycle-progression-and-forecast/

     Updated: Monthly

  7. Monthly F10.7 Predictions

     https://www.nasa.gov/wp-content/uploads/2024/09/sep2024f10-prd.txt

     Contains: Monthly F10.7_Adj for approximately 18.5 years. F10.7_Obs is calculated from F10.7_Adj. The 50th-percentile values are used.

     Format documentation: https://www.nasa.gov/solar-cycle-progression-and-forecast/

     Updated: Monthly

• Additional documentation can be found at:

  • Penticton Solar Radio Flux Values
    

    ftp://ftp.ngdc.noaa.gov/STP/space-weather/solar-data/solar-features/solar-radio/noontime-flux/penticton/documentation/miscellaneous/penticton.txt

  • Geomagnetic K_p Index
    

    http://wwwuser.gwdg.de/~rhennin/kp.html [Link no longer works]

• Process:

  1. Observed data is produced by combining Sources 1, 2, and 3 to the current date. Missing F10.7 values are estimated using linear interpolation (Q=4).

  2. Daily predicted data (a_p and F10.7_Adj) is produced using Source 4. K_p, C_p, and C₉ are estimated from a_p. F10.7_Obs values are calculated using F10.7_Adj, adjusted to Earth orbital radius.

  3. Monthly predicted data (F10.7_Adj) is produced using Source 5. F10.7_Obs values are calculated using F10.7_Adj, adjusted to Earth orbital radius.

  4. Missing values are left blank.

• CSV Data Format:

  DATE,BSRN,ND,KP1,KP2,KP3,KP4,KP5,KP6,KP7,KP8,KP_SUM,AP1,AP2,AP3,AP4,AP5,AP6,AP7,AP8,AP_AVG,CP,C9,ISN,F10.7_OBS,F10.7_ADJ,F10.7_DATA_TYPE,F10.7_OBS_CENTER81,F10.7_OBS_LAST81,F10.7_ADJ_CENTER81,F10.7_ADJ_LAST81
  2000-01-01,2272,7,53,47,40,33,43,30,43,37,327,56,39,27,18,32,15,32,22,30,1.3,6,71,129.9,125.6,OBS,166.2,179.0,161.1,175.0
  

  Field	Description
  DATE	Year-Month-Day (ISO 8601)
  BSRN	Bartels Solar Rotation Number. A sequence of 27-day intervals counted continuously from 1832 Feb 8.
  ND	Number of Day within the Bartels 27-day cycle (01-27).
  KP1	Planetary 3-hour Range Index (Kp) for 0000-0300 UT.
  KP2	Planetary 3-hour Range Index (Kp) for 0300-0600 UT.
  KP3	Planetary 3-hour Range Index (Kp) for 0600-0900 UT.
  KP4	Planetary 3-hour Range Index (Kp) for 0900-1200 UT.
  KP5	Planetary 3-hour Range Index (Kp) for 1200-1500 UT.
  KP6	Planetary 3-hour Range Index (Kp) for 1500-1800 UT.
  KP7	Planetary 3-hour Range Index (Kp) for 1800-2100 UT.
  KP8	Planetary 3-hour Range Index (Kp) for 2100-0000 UT.
  KP_SUM	Sum of the 8 Kp indices for the day. Kp has values of 0o, 0+, 1-, 1o, 1+, 2-, 2o, 2+, ... , 8o, 8+, 9-, 9o, which are expressed in steps of one third unit. These values are multiplied by 10 and rounded to an integer value.
  AP1	Planetary Equivalent Amplitude (Ap) for 0000-0300 UT.
  AP2	Planetary Equivalent Amplitude (Ap) for 0300-0600 UT.
  AP3	Planetary Equivalent Amplitude (Ap) for 0600-0900 UT.
  AP4	Planetary Equivalent Amplitude (Ap) for 0900-1200 UT.
  AP5	Planetary Equivalent Amplitude (Ap) for 1200-1500 UT.
  AP6	Planetary Equivalent Amplitude (Ap) for 1500-1800 UT.
  AP7	Planetary Equivalent Amplitude (Ap) for 1800-2100 UT.
  AP8	Planetary Equivalent Amplitude (Ap) for 2100-0000 UT.
  AP_AVG	Arithmetic average of the 8 Ap indices for the day.
  CP	Cp or Planetary Daily Character Figure. A qualitative estimate of overall level of magnetic activity for the day determined from the sum of the 8 Ap indices. Cp ranges, in steps of one-tenth, from 0 (quiet) to 2.5 (highly disturbed).
  C9	C9. A conversion of the 0-to-2.5 range of the Cp index to one digit between 0 and 9.
  ISN	International Sunspot Number. Records contain the Zurich number through 1980 Dec 31 and the International Brussels number thereafter.
  F10.7_OBS	Observed 10.7-cm Solar Radio Flux (F10.7). Measured at Ottawa at 1700 UT daily from 1947 Feb 14 until 1991 May 31 and measured at Penticton at 2000 UT from 1991 Jun 01 on. Expressed in units of 10-22 W/m2/Hz.
  F10.7_ADJ	10.7-cm Solar Radio Flux (F10.7) adjusted to 1 AU.
  F10.7_DATA_TYPE	Flux Qualifier. OBS: Observed flux measurement INT: CelesTrak linear interpolation of missing data PRD: 45-Day predicted flux PRM: Monthly predicted flux
  F10.7_OBS_CENTER81	Centered 81-day arithmetic average of F10.7 (observed).
  F10.7_OBS_LAST81	Last 81-day arithmetic average of F10.7 (observed).
  F10.7_ADJ_CENTER81	Centered 81-day arithmetic average of F10.7 (adjusted).
  F10.7_ADJ_LAST81	Last 81-day arithmetic average of F10.7 (adjusted).




• Legacy Data Format:

  ----------------------------------------------------------------------------------------------------------------------------------
  FORMAT(I4,I3,I3,I5,I3,8I3,I4,8I4,I4,F4.1,I2,I4,F6.1,I2,5F6.1)
  ----------------------------------------------------------------------------------------------------------------------------------
  Column
  0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001111111111111111111111111111111
  0000000001111111111222222222233333333334444444444555555555566666666667777777777888888888899999999990000000000111111111122222222223
  1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
  ----------------------------------------------------------------------------------------------------------------------------------
                                                                                                Adj     Adj   Adj   Obs   Obs   Obs 
  yyyy mm dd BSRN ND Kp Kp Kp Kp Kp Kp Kp Kp Sum ap  ap  ap  ap  ap  ap  ap  ap  Avg Cp C9 ISN F10.7 Q Ctr81 Lst81 F10.7 Ctr81 Lst81
  ----------------------------------------------------------------------------------------------------------------------------------
  yyyy mm dd nnnn nn nn nn nn nn nn nn nn nn nnn nnn nnn nnn nnn nnn nnn nnn nnn nnn n.n n nnn nnn.n n nnn.n nnn.n nnn.n nnn.n nnn.n
  ----------------------------------------------------------------------------------------------------------------------------------
  2000 01 01 2272  7 53 47 40 33 43 30 43 37 327  56  39  27  18  32  15  32  22  30 1.3 6  71 125.6 0 161.1 175.0 129.9 166.2 179.0
  ----------------------------------------------------------------------------------------------------------------------------------
  

  Columns	Description
  001-004	Year
  006-007	Month (01-12)
  009-010	Day
  012-015	Bartels Solar Rotation Number. A sequence of 27-day intervals counted continuously from 1832 Feb 8.
  017-018	Number of Day within the Bartels 27-day cycle (01-27).
  020-021	Planetary 3-hour Range Index (Kp) for 0000-0300 UT.
  023-024	Planetary 3-hour Range Index (Kp) for 0300-0600 UT.
  026-027	Planetary 3-hour Range Index (Kp) for 0600-0900 UT.
  029-030	Planetary 3-hour Range Index (Kp) for 0900-1200 UT.
  032-033	Planetary 3-hour Range Index (Kp) for 1200-1500 UT.
  035-036	Planetary 3-hour Range Index (Kp) for 1500-1800 UT.
  038-039	Planetary 3-hour Range Index (Kp) for 1800-2100 UT.
  041-042	Planetary 3-hour Range Index (Kp) for 2100-0000 UT.
  044-046	Sum of the 8 Kp indices for the day. Kp has values of 0o, 0+, 1-, 1o, 1+, 2-, 2o, 2+, ... , 8o, 8+, 9-, 9o, which are expressed in steps of one third unit. These values are multiplied by 10 and rounded to an integer value.
  048-050	Planetary Equivalent Amplitude (Ap) for 0000-0300 UT.
  052-054	Planetary Equivalent Amplitude (Ap) for 0300-0600 UT.
  056-058	Planetary Equivalent Amplitude (Ap) for 0600-0900 UT.
  060-062	Planetary Equivalent Amplitude (Ap) for 0900-1200 UT.
  064-066	Planetary Equivalent Amplitude (Ap) for 1200-1500 UT.
  068-070	Planetary Equivalent Amplitude (Ap) for 1500-1800 UT.
  072-074	Planetary Equivalent Amplitude (Ap) for 1800-2100 UT.
  076-078	Planetary Equivalent Amplitude (Ap) for 2100-0000 UT.
  080-082	Arithmetic average of the 8 Ap indices for the day.
  084-086	Cp or Planetary Daily Character Figure. A qualitative estimate of overall level of magnetic activity for the day determined from the sum of the 8 Ap indices. Cp ranges, in steps of one-tenth, from 0 (quiet) to 2.5 (highly disturbed).
  088-088	C9. A conversion of the 0-to-2.5 range of the Cp index to one digit between 0 and 9.
  090-092	International Sunspot Number. Records contain the Zurich number through 1980 Dec 31 and the International Brussels number thereafter.
  094-098	10.7-cm Solar Radio Flux (F10.7) Adjusted to 1 AU. Measured at Ottawa at 1700 UT daily from 1947 Feb 14 until 1991 May 31 and measured at Penticton at 2000 UT from 1991 Jun 01 on. Expressed in units of 10-22 W/m2/Hz.
  100-100	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; and 4 indicates CelesTrak interpolation of missing data.
  102-106	Centered 81-day arithmetic average of F10.7 (adjusted).
  108-112	Last 81-day arithmetic average of F10.7 (adjusted).
  114-118	Observed (unadjusted) value of F10.7.
  120-124	Centered 81-day arithmetic average of F10.7 (observed).
  126-130	Last 81-day arithmetic average of F10.7 (observed).




• Keywords:

  • DATATYPE CssiSpaceWeather
    Specifies the data format type for the file.

  • VERSION major.minor
    Provides major and minor version of current data format.

  • UPDATED yyyy Mon dd hh:mm:ss UTC
    Provides UTC date and time of current update.

  • NUM_OBSERVED_POINTS number
    Indicates number of records of data in the Observed Data section.

  • BEGIN OBSERVED
    END OBSERVED
    Marks beginning and end of the Observed Data section.

  • NUM_DAILY_PREDICTED_POINTS number
    Indicates number of records of data in the Daily Predicted Data section.

  • BEGIN DAILY_PREDICTED
    END DAILY_PREDICTED
    Marks beginning and end of the Daily Predicted Data section.

  • NUM_MONTHLY_PREDICTED_POINTS number
    Indicates number of records of data in the Monthly Predicted Data section.

  • BEGIN MONTHLY_PREDICTED
    END MONTHLY_PREDICTED
    Marks beginning and end of the Monthly Predicted Data section. Data is output for the first day of the month.