AP and F107 data sources and processing

Ap and F107 All observation data . The short-term forecast is within one day ？ The medium and long-term forecast is more than months ？

One 、Ap data

“ Interplanetary three hour magnetotelluric index ” namely Kp Index .Kp Index is the most widely used geomagnetic index , It can reflect the overall activity level of geomagnetic field .Kp The index ranges from 0~9, The larger the value, the greater the disturbance amplitude of geomagnetic field .Kp Exponents are defined on a quasi logarithmic scale , It is not suitable to calculate the daily index by simple average . By switching , Get every three hours ap Index . And will 8 individual ap Average the index to get the daily average index of planetary properties , be called Ap.

1） Measured data

measurement Kp The geomagnetic station of is shown in the figure .

The data is actually from the German Geoscience Research Center GFZ released . Data address ：Geomagnetic Kp indexhttps://doi.org/10.5880/Kp.0001

2） Forecast data

forecasting and prediction Is different . At present, the geomagnetic index can also prediction At most 12 Hours . Longer prediction It's metaphysics .

Systematic Analysis of Machine Learning and Feature Selection Techniques for Prediction of the Kp Index - Zhelavskaya - 2019 - Space Weather - Wiley Online Libraryhttps://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019SW002271noaa Of swpc With forecast ,msfc Of Marshall Solar Cycle Forecast There are also forecasts .swpc There are short-term 27 Weather forecast ,msfc Yes. 11 Annual cycle forecast . 

Two 、F107 data

F107 It is an indicator of solar activity , Express 2800MHz（ wavelength 10.7cm） Solar radiation flux , With s.f.u Express .sfu = 10-22W m-2 Hz-1. It has a good correlation with the number of sunspots . and , It can be measured on the ground , Not subject to weather conditions .F10.7 Index from 1947 Measured by Canada in .

1） Measured data

Data publishing address ：Solar radio flux - solar monitoring program (spaceweather.gc.ca)https://www.spaceweather.gc.ca/forecast-prevision/solar-solaire/solarflux/sx-en.php The data includes observations , Adjustment value and URSI D Series value .

The observed value is the value measured by the solar radio telescope . This is modulated by two quantities ： Changes in the level of solar activity and the distance between the earth and the sun . Because it is produced by the impact of solar radiation on the earth , Therefore, this is the amount used in the study of ground phenomena .

When studying the sun , Because the distance between the earth and the sun changes ,10.7cm Annual modulation of solar flux should be avoided . However , The distance between the sun and the earth can be calculated through the ephemeris . therefore , We generate an extra quantity , According to the earth - Correction for changes in solar distance , The value based on the average distance is called the adjusted value .

The absolute measurement of flux density is quite difficult , And in the early days of solar radio astronomy , Considerable efforts have been made around the world to make absolute measurements of solar flux density at many different frequencies . Then try to fit all these various data into the spectrum . Then provide a scale factor for each group of measurements , Insert them into the fitted spectrum . about 10.7cm Solar energy flux , The estimated scale factor is 0.9. According to the future work , This work should be redone . however , We also give in the database D Series flux , It is the adjusted value multiplied by 0.9.

Conduct flux measurement three times a day . stay 3 Month to 10 During the month , The measurement time is 1700,2000（ Local noon ） and 2300UT. However , The combination of the location in the valley and the relatively high latitude makes it impossible to maintain these times for the rest of the year . therefore , from 11 Month to 2 month , The flux determination time becomes 1800,2000 and 2200, Because the sun is high enough above the horizon to make a good measurement .

2） Forecast data

Medium-term Predictions of F10.7 and F30 cm Solar Radio Flux with the Adaptive Kalman Filter - IOPsciencehttps://iopscience.iop.org/article/10.3847/1538-4365/abef6d1-24 Months forecast .

The prediction of business type is still in the front noaa swpc and msfc.

3、 ... and 、 Summary data

1）celestrak

celestrak The website collects observation data and prediction data , Including geomagnetic activity BSRN, ND, 3-hourly Kp, 3-hourly ap, Cp, C9 And the index of solar activity ： Sum of sunspot number f107. The problem is that there is no geomagnetism kp and ap Forecast data for .

2) iriweb

International ionospheric reference model website irimodel.org Regularly release Ap and F107 And sunspots and other data files . Only observation data , Include ap and f107, The advantage is to give iri The neutral atmosphere model inside does the input data , So there is no redundant data , Direct use , Very convenient .

APF107.dat File format

year, month, day, 3 Hours Ap Index , On the day Ap, Sunspot number , On the day F107,81 God F107,365 God F107

data format

i3, i3, i3, i3*8, i3, i3, f5.1, f5.1, f5.1

notes 1：i3 Represents a three digit integer ,f5.1 Express 1 Decimal place , The length is 5 Floating point number of bits

notes 2： The number of sunspots is not provided ;

notes 3： On the first line of the file f107 It's just after 40 Days of f107 Average .

3）msfc Predictive value

Including sunspots 、f107 and ap The estimated value of the solar cycle from now to the next , Used to serve space missions , Easy to use .Solar Cycle Progression and Forecast | NASAhttps://www.nasa.gov/msfcsolar