Solar-Terrestrial Physics Solar-Terrestrial Physics Solar-Terrestrial Physics 2500-0535 64828 10.12737/stp-94202306 Results of current research Results of current research Results of current research Correlation analysis of solar flux absolute measurements at 161 and 245 MHz Correlation analysis of solar flux absolute measurements at 161 and 245 MHz Сетов Артём Геннадьевич Setov Artem Gennadyevich artemsetov@gmail.com

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 Кушнарев Дмитрий Сергеевич Kushnarev Dmitriy Sergeevich ds_k@iszf.irk.ru

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar-Terrestrial Physics SB RAS Irkutsk Russian Federation Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar Terrestrial Physics SB RAS Irkutsk Russian Federation 28 12 2023 28 12 2023 9 4 46 54 02 06 2023 22 08 2023 https://zh-szf.ru/en/nauka/article/64828/view

Solar emission in meter waves originates from upper layers of the solar corona. We present absolute measurements of solar flux from Irkutsk Incoherent Scatter Radar (161 MHz frequency) and Learmonth Observatory (245 MHz frequency). We perform correlation analysis to investigate the relation between solar flux values at different frequencies. Background emission of the quiet Sun is within the expected limits. We examine the behavior of background and slowly-varying emission components during a solar cycle. By comparing the Pearson correlation coefficient with the Spearman rank correlation coefficient, we have found that the dependence of the meter flux on the F10.7 index is non-linear. The correlation between solar flux measurements at 161 and 245 MHz appeared to be lower than that with the F10.7 index. Analysis of daily correlation and autocorrelation shows a diurnal variation that introduces an error into the measurements.

Solar emission in meter waves originates from upper layers of the solar corona. We present absolute measurements of solar flux from Irkutsk Incoherent Scatter Radar (161 MHz frequency) and Learmonth Observatory (245 MHz frequency). We perform correlation analysis to investigate the relation between solar flux values at different frequencies. Background emission of the quiet Sun is within the expected limits. We examine the behavior of background and slowly-varying emission components during a solar cycle. By comparing the Pearson correlation coefficient with the Spearman rank correlation coefficient, we have found that the dependence of the meter flux on the F10.7 index is non-linear. The correlation between solar flux measurements at 161 and 245 MHz appeared to be lower than that with the F10.7 index. Analysis of daily correlation and autocorrelation shows a diurnal variation that introduces an error into the measurements.

 solar emission absolute measurements Irkutsk Incoherent Scatter Radar (IISR) Learmonth Observatory meter waves background emission slowly-varying component solar emission absolute measurements Irkutsk Incoherent Scatter Radar (IISR) Learmonth Observatory meter waves background emission slowly-varying component The work was financially supported by the Russian Science Foundation (Grant No. 22-17-00146) [https://rscf.ru/project/22-17-00146/] in terms of developing the data processing method and analyzing the results. The work was financially supported by the Ministry of Science and Higher Education of the Russian Federation in terms of observations The work was financially supported by the Russian Science Foundation (Grant No. 22-17-00146) [https://rscf.ru/project/22-17-00146/] in terms of developing the data processing method and analyzing the results. The work was financially supported by the Ministry of Science and Higher Education of the Russian Federation in terms of observations

Benz A.O. Radio emission of the quiet Sun. Landolt Börnstein. 2009, vol. VI/4B, pp. 1-13. DOI: 10.1007/978-3-540-88055-4_5. Benz A.O. Radio emission of the quiet Sun. Landolt Börnstein. 2009, vol. VI/4B, pp. 1-13. DOI: 10.1007/978-3-540-88055-4_5. Borkowski K.M. The quiet Sun brightness temperature at 127 MHz. Solar Phys. 1982, vol. 81, pp. 207-215. DOI: 10.1007/ BF00151297. Borkowski K.M. The quiet Sun brightness temperature at 127 MHz. Solar Phys. 1982, vol. 81, pp. 207-215. DOI: 10.1007/ BF00151297. Giersch O., Kennewell J. Analysis of the radio solar telescope network’s noon flux observations over three solar cycles (1988-2020). Radio Sci. 2022, vol. 57, e2022RS007456. DOI: 10.1029/2022RS007456. Giersch O., Kennewell J. Analysis of the radio solar telescope network’s noon flux observations over three solar cycles (1988-2020). Radio Sci. 2022, vol. 57, e2022RS007456. DOI: 10.1029/2022RS007456. Hamini A., Auxepaules G., Birée L., Kenfack G., Kerdraon A., Klein K.-L., et al. ORFEES - a radio spectrograph for the study of solar radio bursts and space weather applications. J. Space Weather Space Clim. 2021, vol. 11, no. 57. DOI: 10.1051/swsc/2021039. Hamini A., Auxepaules G., Birée L., Kenfack G., Kerdraon A., Klein K.-L., et al. ORFEES - a radio spectrograph for the study of solar radio bursts and space weather applications. J. Space Weather Space Clim. 2021, vol. 11, no. 57. DOI: 10.1051/swsc/2021039. Iwai K, Tsuchiya F., Morioka A., Misawa H. IPRT/AMATERAS: A New Metric Spectrum Observation System for Solar Radio Bursts. Solar Phys. 2012, vol. 277, pp. 447-457. DOI: 10.1007/s11207-011-9919-y. Iwai K, Tsuchiya F., Morioka A., Misawa H. IPRT/AMATERAS: A New Metric Spectrum Observation System for Solar Radio Bursts. Solar Phys. 2012, vol. 277, pp. 447-457. DOI: 10.1007/s11207-011-9919-y. Kashapova L.K., Kolotkov D.Y., Kupriyanova E.G., Kudriavtseva A., Chengming Tan, Reid H. Common origin of quasi-periodic pulsations in microwave and decimetric solar radio bursts. Solar Phys. 2021, vol. 296, no. 185, pp. 1-16. DOI: 10.1007/s11207-021-01934-x. Kashapova L.K., Kolotkov D.Y., Kupriyanova E.G., Kudriavtseva A., Chengming Tan, Reid H. Common origin of quasi-periodic pulsations in microwave and decimetric solar radio bursts. Solar Phys. 2021, vol. 296, no. 185, pp. 1-16. DOI: 10.1007/s11207-021-01934-x. Lantos P. Low frequency observations of the quiet Sun: a review. Proc. Nobeyama Symposium “Solar Physics with Radio Observations”. 1998, pp. 11-24. Lantos P. Low frequency observations of the quiet Sun: a review. Proc. Nobeyama Symposium “Solar Physics with Radio Observations”. 1998, pp. 11-24. Lu L., Liu, S., Song Q., Ning Z. Calibration of Solar Radio Spectrometer of the Purple Mountain Observatory. Chinese Astron. Astrophys. 2015, vol. 39, pp. 497-511. DOI: 10.1016/j.chinastron.2015.10.007. Lu L., Liu, S., Song Q., Ning Z. Calibration of Solar Radio Spectrometer of the Purple Mountain Observatory. Chinese Astron. Astrophys. 2015, vol. 39, pp. 497-511. DOI: 10.1016/j.chinastron.2015.10.007. Medvedev A.V., Potekhin A.P. Irkutsk Incoherent Scatter Radar: history, present and future. History of Geo- and Space Sciences. 2019, vol. 10, pp. 215-224. DOI: 10.5194/hgss-10-215-2019. Medvedev A.V., Potekhin A.P. Irkutsk Incoherent Scatter Radar: history, present and future. History of Geo- and Space Sciences. 2019, vol. 10, pp. 215-224. DOI: 10.5194/hgss-10-215-2019. Oberoi D., Sharma R., Rogers A.E.E. Estimating solar flux density at low radio frequencies using a sky brightness model. Solar Phys. 2017, vol. 292, 75, pp. 1-16. DOI: 10.1007/s11207-017-1096-1. Oberoi D., Sharma R., Rogers A.E.E. Estimating solar flux density at low radio frequencies using a sky brightness model. Solar Phys. 2017, vol. 292, 75, pp. 1-16. DOI: 10.1007/s11207-017-1096-1. Potekhin A.P., Medvedev A.V., Zavorin A.V., Kushnarev D.S., Lebedev V.P, Lepetaev V.V., Shpynev B.G. Recording and control digital systems of the Irkutsk Incoherent Scatter Radar. Geomagnetism and Aeronomy. 2009, vol. 49, no. 7, pp. 1011-1021. DOI: 10.1134/S0016793209070299. Potekhin A.P., Medvedev A.V., Zavorin A.V., Kushnarev D.S., Lebedev V.P, Lepetaev V.V., Shpynev B.G. Recording and control digital systems of the Irkutsk Incoherent Scatter Radar. Geomagnetism and Aeronomy. 2009, vol. 49, no. 7, pp. 1011-1021. DOI: 10.1134/S0016793209070299. Setov A.G., Globa M.V., Medvedev A.V., Vasilyev R.V., Kushnarev D.S. First results of absolute measurements of solar flux at the Irkutsk Incoherent Scatter Radar (IISR). Solar-Terr. Phys. 2018, vol. 4, Iss. 3, pp.24-27. DOI: 10.12737/stp-43201804. Setov A.G., Globa M.V., Medvedev A.V., Vasilyev R.V., Kushnarev D.S. First results of absolute measurements of solar flux at the Irkutsk Incoherent Scatter Radar (IISR). Solar-Terr. Phys. 2018, vol. 4, Iss. 3, pp.24-27. DOI: 10.12737/stp-43201804. Setov A.G., Kushnarev D.S., Vasilyev R.V., Medvedev A.V. Long-term solar flux observations with Irkutsk Incoherent Scatter Radar (IISR) in 2011-2019. Solar-Terr. Phys. 2020, vol. 6, Iss. 3, pp. 29-33. DOI: 10.12737/stp-63202004. Setov A.G., Kushnarev D.S., Vasilyev R.V., Medvedev A.V. Long-term solar flux observations with Irkutsk Incoherent Scatter Radar (IISR) in 2011-2019. Solar-Terr. Phys. 2020, vol. 6, Iss. 3, pp. 29-33. DOI: 10.12737/stp-63202004. Spearman C. The Proof and Measurement of Association between Two Things. The Americal J. Psychology. 1904, vol. 15, no. 1, pp. 72-101. DOI: 10.2307/1412159. Spearman C. The Proof and Measurement of Association between Two Things. The Americal J. Psychology. 1904, vol. 15, no. 1, pp. 72-101. DOI: 10.2307/1412159. Tan C., Yan Y., Tan B., Fu Q., Liu Y., Xu G. Study of calibration of solar radio spectrometers and the quiet-Sun radio emission. Astrophys. J. 2015, vol. 808, 61. DOI: 10.1088/0004-637X/808/1/61. Tan C., Yan Y., Tan B., Fu Q., Liu Y., Xu G. Study of calibration of solar radio spectrometers and the quiet-Sun radio emission. Astrophys. J. 2015, vol. 808, 61. DOI: 10.1088/0004-637X/808/1/61. Tapping K.F. The 10.7 cm solar radio flux (F10.7). Space Weather. 2013, vol. 11, pp. 394-406. DOI: 10.1002/swe.20064. Tapping K.F. The 10.7 cm solar radio flux (F10.7). Space Weather. 2013, vol. 11, pp. 394-406. DOI: 10.1002/swe.20064. Vocks C., Mann G., Breitling F., Bisi M., Dąbrowski B., Fallows R., et al. LOFAR observations of the quiet solar corona. Astron. Astrophys. 2018, vol. 614, no. A54, pp. 1-9. DOI: 10.1051/0004-6361/201630067. Vocks C., Mann G., Breitling F., Bisi M., Dąbrowski B., Fallows R., et al. LOFAR observations of the quiet solar corona. Astron. Astrophys. 2018, vol. 614, no. A54, pp. 1-9. DOI: 10.1051/0004-6361/201630067. Zheng H., Tegmark M., Dillon J.S., Kim D.A., Liu A., Neben A., et al. An improved model of diffuse galactic radio emission from 10 MHz to 5 THz. Monthly Notices Royal Astron. Soc. 2016, vol. 464, no. 3, pp. 3486-3497. DOI: 10.1093/mnras/stw2525. Zheng H., Tegmark M., Dillon J.S., Kim D.A., Liu A., Neben A., et al. An improved model of diffuse galactic radio emission from 10 MHz to 5 THz. Monthly Notices Royal Astron. Soc. 2016, vol. 464, no. 3, pp. 3486-3497. DOI: 10.1093/mnras/stw2525. URL: https://www.sws.bom.gov.au/Solar/3/4 (accessed June 2, 2023). URL: https://www.sws.bom.gov.au/Solar/3/4 (accessed June 2, 2023). URL: https://rscf.ru/project/22-17-00146/ (accessed September 29, 2023). URL: https://rscf.ru/project/22-17-00146/ (accessed September 29, 2023). URL: http://ckp-rf.ru/usu/77733/ (accessed September 29, 2023). URL: http://ckp-rf.ru/usu/77733/ (accessed September 29, 2023). URL: ftp://ftp-out.sws.bom.gov.au (accessed June 2, 2023). URL: ftp://ftp-out.sws.bom.gov.au (accessed June 2, 2023).