<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article
PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.4 20190208//EN"
       "JATS-journalpublishing1.dtd">
<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" article-type="research-article" dtd-version="1.4" xml:lang="en">
 <front>
  <journal-meta>
   <journal-id journal-id-type="publisher-id">Solar-Terrestrial Physics</journal-id>
   <journal-title-group>
    <journal-title xml:lang="en">Solar-Terrestrial Physics</journal-title>
    <trans-title-group xml:lang="ru">
     <trans-title>Солнечно-земная физика</trans-title>
    </trans-title-group>
   </journal-title-group>
   <issn publication-format="online">2712-9640</issn>
  </journal-meta>
  <article-meta>
   <article-id pub-id-type="publisher-id">122578</article-id>
   <article-id pub-id-type="doi">10.12737/szf-122202601</article-id>
   <article-id pub-id-type="edn">ilwjso</article-id>
   <article-categories>
    <subj-group subj-group-type="toc-heading" xml:lang="ru">
     <subject>Результаты  исследований</subject>
    </subj-group>
    <subj-group subj-group-type="toc-heading" xml:lang="en">
     <subject>Results of current research</subject>
    </subj-group>
    <subj-group>
     <subject>Результаты  исследований</subject>
    </subj-group>
   </article-categories>
   <title-group>
    <article-title xml:lang="en">Waldmeier law for sunspot cycles: Statistical significance and implications for dynamo</article-title>
    <trans-title-group xml:lang="ru">
     <trans-title>Правило Вальдмайера для солнечных циклов: статистическая достоверность и значение для динамо</trans-title>
    </trans-title-group>
   </title-group>
   <contrib-group content-type="authors">
    <contrib contrib-type="author">
     <name-alternatives>
      <name xml:lang="ru">
       <surname>Кичатинов</surname>
       <given-names>Леонид Леонидович</given-names>
      </name>
      <name xml:lang="en">
       <surname>Kitchatinov</surname>
       <given-names>Leonid Leonidovich</given-names>
      </name>
     </name-alternatives>
     <email>kit@iszf.irk.ru</email>
     <bio xml:lang="ru">
      <p>доктор физико-математических наук;</p>
     </bio>
     <bio xml:lang="en">
      <p>doctor of physical and mathematical sciences;</p>
     </bio>
     <xref ref-type="aff" rid="aff-1"/>
    </contrib>
   </contrib-group>
   <aff-alternatives id="aff-1">
    <aff>
     <institution xml:lang="ru">Институт солнечно-земной физики СО РАН</institution>
     <city>Иркутск</city>
     <country>Россия</country>
    </aff>
    <aff>
     <institution xml:lang="en">Institute of Solar-Terrestrial Physics SB RAS</institution>
     <city>Irkutsk</city>
     <country>Russian Federation</country>
    </aff>
   </aff-alternatives>
   <volume>12</volume>
   <issue>2</issue>
   <fpage>5</fpage>
   <lpage>9</lpage>
   <history>
    <date date-type="received" iso-8601-date="2026-02-25T00:00:00+03:00">
     <day>25</day>
     <month>02</month>
     <year>2026</year>
    </date>
    <date date-type="accepted" iso-8601-date="2026-04-06T00:00:00+03:00">
     <day>06</day>
     <month>04</month>
     <year>2026</year>
    </date>
   </history>
   <self-uri xlink:href="https://naukaru.ru/en/nauka/article/122578/view">https://naukaru.ru/en/nauka/article/122578/view</self-uri>
   <abstract xml:lang="ru">
    <p>Правило Вальдмайера для соотношения длительности фазы роста и амплитуды солнечных циклов является индикатором степени нелинейности механизма динамо. В работе проведено сравнение параметров правила Вальдмайера для чисел и площадей солнечных пятен в циклах активности с 12 по 25. Неоднозначность в датах минимумов   и максимумов циклов устранена сглаживанием гауссовым фильтром. Показано, что соотношения чисел и площадей пятен существенно отличаются для фаз роста и спада активности. При этом высокая корреляция для правила Вальдмайера в числах пятен является артефактом определения чисел Вольфа и не означает высокой степени нелинейности механизма динамо. Относительно низкая корреляция и уровень достоверности ~70 % для правила Вальдмайера, определяемого по площадям пятен, указывает на слабую нелинейность в солнечном динамо и согласуется со свидетельcтвами, следующими из наблюдений вращения звезд.</p>
   </abstract>
   <trans-abstract xml:lang="en">
    <p>Waldmeier law for the relation between the rise phase duration and amplitude of solar cycles is an indicator for strength of nonlinearity in the solar dynamo. The paper compares the Waldmeier law parameters for sunspot number and area in solar cycles 12–25. Uncertainty in dates of cycles’ maxima and minima is fixed by smoothing with the Gaussian filter. The ratio of sunspot number to area is shown to differ significantly between rise and decline phases of solar activity. The high correlation for Waldmeier law in sunspot number is an artifact of the Wolf number definition and does not imply any strong nonlinearity in the dynamo mechanism. The relative low correlation and significance level of about 70 % in Waldmeier law for sunspot area indicates a weak nonlinearity in the solar dynamo and agrees with evidences from observations of stellar rotation.</p>
   </trans-abstract>
   <kwd-group xml:lang="ru">
    <kwd>cолнечная активность</kwd>
    <kwd>числа пятен</kwd>
    <kwd>площадь пятен</kwd>
    <kwd>динамо</kwd>
    <kwd>нелинейность</kwd>
   </kwd-group>
   <kwd-group xml:lang="en">
    <kwd>solar activity</kwd>
    <kwd>sunspot number</kwd>
    <kwd>sunspot area</kwd>
    <kwd>dynamo</kwd>
    <kwd>nonlinearity</kwd>
   </kwd-group>
   <funding-group>
    <funding-statement xml:lang="ru">Работа выполнена при финансовой поддержке Минобрнауки России</funding-statement>
    <funding-statement xml:lang="en">This work is financially supported by the Ministry of Science and High Education of the Russian Federation</funding-statement>
   </funding-group>
  </article-meta>
 </front>
 <body>
  <p></p>
 </body>
 <back>
  <ref-list>
   <ref id="B1">
    <label>1.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Витинский Ю.И., Копецкий М., Куклин Г.В. Статистика пятнообразовательной деятельности Солнца. М.: Наука, 1986, 296 с.</mixed-citation>
     <mixed-citation xml:lang="en">Badalyan O.G., Obridko V.N. North-South asymmetry of the sunspot indeces and its quasi-biennual oscillations. New Astronomy. 2011, vol. 16, iss. 6, pp. 357–365. https://doi.org/10.1016/j.newast.2011.01.005.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B2">
    <label>2.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Кичатинов Л.Л., Олемской С.В. Действует ли механизм Бэбкока—Лейтона на Солнце? Письма в АЖ. 2011, т. 37, № 9, с. 713–715. https://doi.org/10.1134/S0320010811080031.</mixed-citation>
     <mixed-citation xml:lang="en">Cameron R.H., Schussler M. Understandiang solar cycle variability. Astrophys. J. 2017, vol. 843, iss. 2, id. 111. https://doi.org/10.3847/1538-4357/aa767a.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B3">
    <label>3.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Кичатинов Л.Л. Непомнящих А.А. Согласованная модель солнечного динамо и дифференциального вращения. Письма в АЖ. 2017, т. 43, № 5, с. 370–382. https://doi.org/10.7868/S0320010817040039.</mixed-citation>
     <mixed-citation xml:lang="en">Carrasco V.M.S., Vaquero J.M., Gallego M.C., Sanchez-Bajo F. A normalized sunspot-area series starting in 1832: An update. Solar Phys. 2016, vol. 291, iss. 9-10, pp. 2931–2940. https://doi.org/10.1007/s11207-016-0943-9.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B4">
    <label>4.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Наговицын Ю.А., Певцов А.А., Осипова А.А. и др. Две популяции солнечных пятен и вековые вариации их характеристик. Письма в АЖ. 2016, т. 42, № 10, с. 773–782. https://doi.org/10.1134/S1063773716090048.</mixed-citation>
     <mixed-citation xml:lang="en">Charbonneau P. Dynamo models of the solar cycle. Living Rev. Solar Phys. 2020, vol. 17, iss. 1, id. 4. https://doi.org/10.1007/s41116-020-00025-6.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B5">
    <label>5.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Олемской С.В., Чудури А.Р., Кичатинов Л.Л. Флуктуации альфа-эффекта и глобальные минимумы солнечной активности. Астрономический журнал. 2013, т. 90, № 6, с. 501–511. https://doi.org/10.7868/S000462991305006X.</mixed-citation>
     <mixed-citation xml:lang="en">Charbonneau P., Sokoloff D. Evolution of solar and stellar dynamo theory. Space Sci. Rev. 2023, vol. 219, iss. 5, id. 35. https://doi.org/10.1007/s11214-023-00980-0.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B6">
    <label>6.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Badalyan O.G., Obridko V.N. North-South asymmetry of the sunspot indeces and its quasi-biennual oscillations. New Astronomy. 2011, vol. 16, iss. 6, pp. 357–365. https://doi.org/10.1016/j.newast.2011.01.005.</mixed-citation>
     <mixed-citation xml:lang="en">Dasi-Espuig M., Solanki S.K., Krivova N.A., et al. Sunspot group tilt angles and the strength of the solar cycle. Astron. Astrophys. 2010, vol. 518, id. A7. https://doi.org/10.1051/0004-6361/201014301</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B7">
    <label>7.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Cameron R.H., Schussler M. Understandiang solar cycle variability. Astrophys. J. 2017, vol. 843, iss. 2, id. 111. https://doi.org/10.3847/1538-4357/aa767a.</mixed-citation>
     <mixed-citation xml:lang="en">Dikpati M., Gilman P.A., de Toma G. The Waldmeier effect: An artifact of the definition of Wolf sunspot number? Astrophys. J. Lett. 2008, vol. 673, iss. 1, id.: L99. https://doi.org/10.1086/527360.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B8">
    <label>8.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Carrasco V.M.S., Vaquero J.M., Gallego M.C., Sanchez-Bajo F. A normalized sunspot-area series starting in 1832: An update. Solar Phys. 2016, vol. 291, iss. 9-10, pp. 2931–2940. https://doi.org/10.1007/s11207-016-0943-9.</mixed-citation>
     <mixed-citation xml:lang="en">Garg S., Karak B.B., Egeland R., et al. Waldmeier effect in stellar cycles. Astrophys. J. 2019, vol. 886, iss. 2, id. 132. https://doi.org/10.3847/1538-4357/ab4a17.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B9">
    <label>9.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Charbonneau P. Dynamo models of the solar cycle. Living Revews in Solar Physics. 2020, vol. 17, iss. 1, id. 4. https://doi.org/10.1007/s41116-020-00025-6.</mixed-citation>
     <mixed-citation xml:lang="en">Hathaway D.H. The solar cycle. Living Rev. in Solar Phys. 2015, vol. 12, no. 1, id. 4. https://doi.org/10.1007/lrsp-2015-4.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B10">
    <label>10.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Charbonneau P., Sokoloff D. Evolution of solar and stellar dynamo theory. Space Sci. Rev. 2023, vol. 219, iss. 5, id. 35. https://doi.org/10.1007/s11214-023-00980-0.</mixed-citation>
     <mixed-citation xml:lang="en">Jiang J., Cameron R.H., Schmitt D., Isik E. Modeling solar cycles 15 to 21 using a flux transport dynamo. Astron. Astrophys. 2013, vol. 553, id. A128. https://doi.org/10.1051/0004-6361/201321145.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B11">
    <label>11.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Dasi-Espuig M., Solanki S.K., Krivova N.A., et al. Sunspot group tilt angles and the strength of the solar cycle. Astron. Astrophys. 2010, vol. 518, id. A7.https://doi.org/10.1051/0004-6361/201014301.</mixed-citation>
     <mixed-citation xml:lang="en">Karak B.B., Choudhuri A.R. The Waldmeier effect and the flux-transport solar dynamo. Monthly Notices of the Royal Astronomical Society. 2011, vol. 410, iss. 3, pp. 1503–1512. https://doi.org/10.1111/j.1365-2966.2010.17531.x.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B12">
    <label>12.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Dikpati M., Gilman P.A., de Toma G. The Waldmeier effect: An artifact of the definition of Wolf sunspot number? Astrophys. J. Lett. 2008, vol. 673, iss. 1, id.: L99. https://doi.org/10.1086/527360.</mixed-citation>
     <mixed-citation xml:lang="en">Kitchatinov L.L. Flux tubes forming instability near the base of the rotating convection zone: A possible explanation for the low latitudes of sunspots. Astrophys. J. 2020, vol. 893, iss. 2, id. 131. https://doi.org/10.3847/1538-4357/ab7fa8.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B13">
    <label>13.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Garg S., Karak B.B., Egeland R., et al. Waldmeier effect in stellar cycles. Astrophys. J. 2019, vol. 886, iss. 2, id. 132. https://doi.org/10.3847/1538-4357/ab4a17.</mixed-citation>
     <mixed-citation xml:lang="en">Kitchatinov L.L., Olemskoy S.V. Does the Babcock-Leighton mechanism operate on the Sun? Astron. Lett. 2011, vol. 37, iss. 9, pp. 656–658. https://doi.org/10.1134/S0320010811080031.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B14">
    <label>14.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Hathaway D.H. The solar cycle. Living Revews in Solar Physics. 2015, vol. 12, no. 1, id. 4. https://doi.org/10.1007/lrsp-2015-4.</mixed-citation>
     <mixed-citation xml:lang="en">Kitchatinov L.L., Nepomnyashchikh A.A. A joined model for solar dynamo and differential rotation. Astron. Lett. 2017a, vol. 43, iss. 5, pp. 332–343. https://doi.org/10.1134/S106377371704003X.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B15">
    <label>15.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Jiang J., Cameron R.H., Schmitt D., Isik E. Modeling solar cycles 15 to 21 using a flux transport dynamo. Astron. Astrophys. 2013, vol. 553, id. A128. https://doi.org/10.1051/0004-6361/201321145.</mixed-citation>
     <mixed-citation xml:lang="en">Kitchatinov L., Nepomnyashchikh A. How supercritical are stellar dynamos, or why do old main-sequence dwarfs not obey gyrochronology? Monthly Not. Royal Astron. Soc. 2017b, vol. 470, iss. 3, pp. 3124–3130. https://doi.org/10.1093/mnras/stx1473.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B16">
    <label>16.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Karak B.B., Choudhuri A.R. The Waldmeier effect and the flux-transport solar dynamo. Monthly Notices of the Royal Astronomical Society. 2011, vol. 410, iss. 3, pp. 1503–1512. https://doi.org/10.1111/j.1365-2966.2010.17531.x.</mixed-citation>
     <mixed-citation xml:lang="en">Metcalfe T.S., Egeland R., van Saders J. Stellar evidence that the solar dynamo may be in transition. Astrophys. J. Lett. 2016, vol. 826, iss. 1, id. L2. https://doi.org/10.3847/2041-8205/826/1/L2.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B17">
    <label>17.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Kitchatinov L.L. Flux tubes forming instability near the base of the rotating convection zone: A possible explanation for the low latitudes of sunspots. Astrophys. J. 2020, vol. 893, iss. 2, id. 131. https://doi.org/10.3847/1538-4357/ab7fa8.</mixed-citation>
     <mixed-citation xml:lang="en">Moss D., Sokoloff D., Usoskin I. Solar grand minima and random fluctuations in dynamo parameters. Solar Phys. 2008, vol. 250, iss. 2, id. 221. https://doi.org/10.1007/s11207-008-9202-z.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B18">
    <label>18.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Kitchatinov L., Nepomnyashchikh A. How supercritical are stellar dynamos, or why do old main-sequence dwarfs not obey gyrochronology? Monthly Notices of the Royal Astronomical Society. 2017, vol. 470, iss. 3, pp. 3124–3130. https://doi.org/10.1093/mnras/stx1473.</mixed-citation>
     <mixed-citation xml:lang="en">Nagovitsyn Yu.A., Pevtsov A.A. On the presence of two populations of sunspots. Astrophys. J. 2016, vol. 833, iss. 1, id. 94. https://doi.org/10.3847/1538-4357/833/1/94.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B19">
    <label>19.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Metcalfe T.S., Egeland R., van Saders J. Stellar evidence that the solar dynamo may be in transition. Astrophys. J. Lett. 2016, vol. 826, iss. 1, id. L2. https://doi.org/10.3847/2041-8205/826/1/L2.</mixed-citation>
     <mixed-citation xml:lang="en">Nagovitsyn Yu.A., Osipova A.A. Average annual total sunspot area in the last 410 yr: the most probable values and limits of their uncertainties.  Monthly Not. Royal Astron. Soc. 2021, vol. 505, iss. 1, pp. 1206–1212. https://doi.org/10.1093/mnras/stab1328.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B20">
    <label>20.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Moss D., Sokoloff D., Usoskin I. Solar grand minima and random fluctuations in dynamo parameters. Solar Phys. 2008, vol. 250, iss. 2, id. 221. https://doi.org/10.1007/s11207-008-9202-z.</mixed-citation>
     <mixed-citation xml:lang="en">Nagovitsyn Yu.A., Pevtsov A.A., Livingston W.C. On a possible explanation of the long-term decrease in sunspot field strength. Astrophys. J. Lett. 2012, vol. 758, iss. 1, id. L20. https://doi.org/10.1088/2041-8205/758/1/L20.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B21">
    <label>21.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Nagovitsyn Yu.A., Pevtsov A.A. On the presence of two populations of sunspots. Astrophys. J. 2016, vol. 833, iss. 1, id. 94. https://doi.org/10.3847/1538-4357/833/1/94.</mixed-citation>
     <mixed-citation xml:lang="en">Nagovitsyn Yu.A., Pevtsov A.A., Osipova A.A., et al. Two populations of sunspots and secular variations of their characteristics. Astron. Lett. 2016, vol. 42, iss. 10, pp. 703–712. https://doi.org/10.1134/S1063773716090048.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B22">
    <label>22.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Nagovitsyn Yu.A., Osipova A.A. Average annual total sunspot area in the last 410 yr: the most probable values and limits of their uncertainties.  Monthly Notices of the Royal Astronomical Society. 2021, vol. 505, iss. 1, pp. 1206–1212. https://doi.org/10.1093/mnras/stab1328.</mixed-citation>
     <mixed-citation xml:lang="en">Olemskoy S.V., Choudhuri A.R., Kitchatinov L.L. Fluctuations in the alpha-effect and grand solar minima. Astron. Rep. 2013, vol. 57, iss. 6, pp. 458–468. https://doi.org/10.1134/S1063772913050065.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B23">
    <label>23.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Nagovitsyn Yu.A., Pevtsov A.A., Livingston W.C. On a possible explanation of the long-term decrease in sunspot field strength. Astrophys. J. Lett. 2012, vol. 758, iss. 1, id. L20. https://doi.org/10.1088/2041-8205/758/1/L20.</mixed-citation>
     <mixed-citation xml:lang="en">Osipova A.A., Nagovitsyn Yu.A. The Waldmeier effect for two sunspot populations. Geomagnetism and Aeronomy. 2017, vol. 57, iss. 8, pp. 1092–1100. https://doi.org/10.1134/S0016793217080199.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B24">
    <label>24.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Osipova A.A., Nagovitsyn Yu.A. The Waldmeier effect for two sunspot populations. Geomagnetism and Aeronomy. 2017, vol. 57, iss. 8, pp. 1092–1100. https://doi.org/10.1134/S0016793217080199.</mixed-citation>
     <mixed-citation xml:lang="en">Pipin V.V., Kosovichev A.G. The asymmetry of sunspot cycles and Waldmeier relation as a result of nonlinear surface-shear shaped dynamo. Astrophys. J. 2011, vol. 741, iss. 1, id. 1. https://doi.org/10.1088/0004-637X/741/1/1.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B25">
    <label>25.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Pipin V.V., Kosovichev A.G. The asymmetry of sunspot cycles and Waldmeier relation as a result of nonlinear surface-shear shaped dynamo. Astrophys. J. 2011, vol. 741, iss. 1, id. 1. https://doi.org/10.1088/0004-637X/741/1/1.</mixed-citation>
     <mixed-citation xml:lang="en">Sreedevi A., Jha B.K., Karak B.B., Banerjee D. Analysis of BMR tilt from Auto TAB catalog: Hinting towards thin flux tube model? Astrophys. J. 2024, vol. 966, iss. 1, id. 112. https://doi.org/10.3847/1538-4357/ad34b8.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B26">
    <label>26.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Sreedevi A., Jha B.K., Karak B.B., Banerjee D. Analysis of BMR tilt from Auto TAB catalog: Hinting towards thin flux tube model? Astrophys. J. 2024, vol. 966, iss. 1, id. 112. https://doi.org/10.3847/1538-4357/ad34b8.</mixed-citation>
     <mixed-citation xml:lang="en">Tlatov A.G., Pevtsov A.A. Bimodal distribution of magnetic fields and areas of sunspots. Solar Phys. 2014, vol. 289, iss. 4, pp. 1143–1152. https://doi.org/10.1007/s11207-013-0382-9.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B27">
    <label>27.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Tlatov A.G., Pevtsov A.A. Bimodal distribution of magnetic fields and areas of sunspots. Solar Phys. 2014, vol. 289, iss. 4, pp. 1143–1152. https://doi.org/10.1007/s11207-013-0382-9.</mixed-citation>
     <mixed-citation xml:lang="en">van Saders J.L., Ceillier T., Metcalfe T.S., et al. Weakend magnetic braking as the origin of anomalously rapid rotation in old field stars. Nature. 2016, vol. 529, iss. 7585, pp. 181–184. https://doi.org/10.1038/nature16168.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B28">
    <label>28.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">van Saders J.L., Ceillier T., Metcalfe T.S., et al. Weakend magnetic braking as the origin of anomalously rapid rotation in old field stars. Nature. 2016, vol. 529, iss. 7585, pp. 181–184. https://doi.org/10.1038/nature16168.</mixed-citation>
     <mixed-citation xml:lang="en">Vitinsky Yu.I., Kopecky M., Kuklin G.V. Statistics of Sunspot Activity. Moscow, Nauka, 1986, 296 p. [In Rissian].</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B29">
    <label>29.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">Waldmeier M. Neue Eigenshaften der Sonnenfleckenkurve. Astron. Mitt. Zurich. 1935, vol. 14. pp. 105–136.</mixed-citation>
     <mixed-citation xml:lang="en">Waldmeier M. Neue Eigenshaften der Sonnenfleckenkurve. Astron. Mitt. Zurich. 1935, vol. 14. pp. 105–136.</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B30">
    <label>30.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">URL: http://solarcyclescience.com/AR_Database/sunspot_area.txt (дата обращения 11 февраля 2026 г.).</mixed-citation>
     <mixed-citation xml:lang="en">URL: http://solarcyclescience.com/AR_Database/sunspot_area.txt (accessed December 12, 2025).</mixed-citation>
    </citation-alternatives>
   </ref>
   <ref id="B31">
    <label>31.</label>
    <citation-alternatives>
     <mixed-citation xml:lang="ru">URL: http://www.wdcb.ru/stp/data/solar.act/sunspot/SILSO/ver2/SN_m/SN_m_tot_V2.0.txt (дата обращения 11 февраля 2026 г.).</mixed-citation>
     <mixed-citation xml:lang="en">URL: http://www.wdcb.ru/stp/data/solar.act/sunspot/SILSO/ver2/SN_m/SN_m_tot_V2.0.txt (accessed December 12, 2025).</mixed-citation>
    </citation-alternatives>
   </ref>
  </ref-list>
 </back>
</article>
