Solar cycle 25

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Solar cycle 25
Solar Cycle 25 prediction and progression.png
ISES Solar Cycle 25 Sunspot Number Progression and Predictions as of November 2021
Sunspot data
Start dateDecember 2019
Max count34.0
Max count monthOctober 2021 (progressive)
Min count1.8
Cycle chronology
Previous cycleSolar cycle 24 (2008-2019)

Solar cycle 25 is the current solar cycle, the 25th since 1755, when extensive recording of solar sunspot activity began. It began in December 2019 with a smoothed minimum sunspot number of 1.8.[1] It is expected to continue until about 2030.[2][3]

Predictions[edit]

Widely varying predictions regarding the strength of cycle 25 ranged from very weak with suggestions of slow slide in to a Maunder minimum like state[4][5] to a weak cycle similar to previous cycle 24[6] and even a strong cycle.[7][8][9] Upton and Hathaway have predicted that the weakness of cycle 25 would make it part of the Modern Gleissberg Minimum.[4] One published prediction (of a very weak cycle) was retracted due to fundamental errors.[10]

The Solar Cycle 25 Prediction Panel predicted in December 2019[11] that solar cycle 25 will be similar to solar cycle 24, with the preceding solar cycle minimum in April 2020 (± 6 months), and the number of sunspots reaching a (smoothed) maximum of 115 in July 2025 (± 8 months). This prediction is in line with the current general agreement in the scientific literature, which holds that solar cycle 25 will be weaker than average (i.e. weaker than during the exceptionally strong Modern Maximum).[6]

Cycle 25 predictions
Source Date Cycle max Cycle start Cycle end
Thompson, M.J. et al.[3] August 2014 Q4 2019
Zharkova, V. et al 2014, 2015.[12] (Northumbria U.) October 2014 80% of cycle 24
Upton, L.A. and Hathaway, D.H.[4] (Solar Observatories Group, Stanford University) December 2018 95% of cycle 24 Late 2020 – Early 2021
Xu, J.C. et al.[7] (Chinese Academy of Sciences) August 2018 152.2–184.8 (2024) October 2020
Bhowmik, P. and Nandy, D.[6] (IISER Kolkata) December 2018 109–139 (2023–2025) 2020 after 2031
Ozguc, A. et al.[8] (Harvard U-ty) December 2018 154±12 (2023.2±1.1)
NOAA / SSRC[13] April 2019 95–130 (2023–2026) mid-2019 – late 2020
NASA[14] June 2019 30–50% lower than Cycle 24 (2025) 2020
NOAA / SSRC (update)[15] December 2019 105–125 (July 2025) April 2020 (± 6 months)
National Center for Atmospheric Research[16] December 2020 233

Early signs[edit]

Time vs. solar latitude diagram of the radial component of the solar magnetic field (supersynoptic map or “butterfly” diagram) for Cycle 24 based on the (zero-point corrected) integer rotation synoptic maps from GONG. Blue/red show negative/positive polarity fields scaled between ±5 Gauss. Two black arrows mark approximate location of two latitudinal bands of Cycle 25. Data are acquired by GONG instruments operated by NISP/NSO/AURA/NSF.

As of April 2018, the Sun showed signs of a reverse magnetic polarity sunspot appearing and beginning this solar cycle.[17] It is typical during the transition from one cycle to the next to experience a period where sunspots of both polarities exist (during the solar minimum). The polarward reversed polarity sunspots suggest that a transition to cycle 25 is in process.[18] The first Cycle 25 sunspot may have appeared in early April 2018[19][20] or even December 2016.[18]

In November 2019, two reversed polarity sunspots appeared, possibly signaling the onset of cycle 25.[21][22]

Nandy et al., analyzed the polarity orientation of bipolar magnetic regions observed in December 2019 and concluded that magnetic regions with the underlying orientation of solar cycle 25 toroidal field component were brewing in the solar convection zone, representing early signs of the new cycle.[23]

Supersynoptic (time vs. solar latitude) map of the radial component of the solar magnetic field for Cycles 24-25 based on observations from the Global Oscillations Network Group (GONG) shows magnetic activity of cycle 25 beginning November 2019 at about 30 degree latitudes in both solar hemispheres.[24] A more recent supersynoptic map is available.[25]

Spotless days by year (Solar cycle 25 vs 24)

  • 2021 : 60 (19%) ... (to November 5)
  • 2020 : 192 (52%)
  • 2019 : 274 (75%)
  • 2018 : 208 (57%)
  • 2017 : 96 (26%)
  • 2016 : 27 (7%)
  • 2015 : 0 (0%)
  • 2014 : 1 (0%)
  • 2013 : 0 (0%)
  • 2012 : 0 (0%)
  • 2011 : 2 (1%)
  • 2010 : 44 (12%)
  • 2009 : 262 (72%)
  • 2008 : 265 (72%)
  • 2007 : 163 (45%)
  • 2006 : 65 (18%)

Events[edit]

Solar flares by year
0.5
1
1.5
2
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
  •   M5-M9
  •   X1-X5
  •   X5-X9
The strongest flares of Solar Cycle 25 (above M5.0 class) and related events
Class Year Date Sunspot region Radio B. SR Storm CME GM Storm
X1.59 2021 Jul 3 2838 R3 - Yes -
X1.0 2021 Oct 28 2887 R3 S1 Yes -
M5.5 2022 Jan 20 2929 R2 S1 ? -

2020[edit]

Solar flares in 2020[26]
10
20
30
40
50
60
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
  •   C
  •   M
  •   X

On 29 May, the first C-class solar flares of Solar Cycle 25 took place, as well as the first M-class flare. Solar activity continued to increase in the following months, especially abruptly in October, with flares taking place on a near-daily basis by November. On 29 November, an M4.4 flare, the strongest of the cycle to date, took place, possibly indicating the solar cycle would be more active than initially thought.[27]

On 8 December, a small coronal mass ejection was found heading directly towards Earth shortly after a strong C-class solar flare, hitting the planet on 9-10 December and causing bright aurorae at high latitudes.[28][29]

2021[edit]

Solar flares in 2021[30]
50
100
150
200
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
  •   C
  •   M
  •   X

The first X-class solar flare of the cycle took place on 3 July, peaking at X1.59.[31]

On 22 July, a total of six different active regions were seen on the solar disk for the first time since 6 September 2017.[32]

On 9 October, a M1.6 class solar flare erupted sending a coronal mass ejection that hit earth on 12 October triggering a (moderate) G2 geomagnetic storm.[33]

The second X-class flare of the solar cycle erupted on 28 October, producing a CME and a S1 solar radiation storm.[34] Reports initially predicted that the CME could graze Earth,[34] however geomagnetic storms on 30-31 October only reached a moderate Kp index of 4.[35]

On 3 and 4 November, the Kp index reached 8-, equivalent to a G4 geomagnetic storm.[36] This was the most intense geomagnetic storm to hit Earth since September 2017.

See also[edit]

References[edit]

  1. ^ National Weather Service. "Hello Solar Cycle 25". Retrieved 15 September 2020.
  2. ^ Odenwald, Sten (2 September 2016). "Waiting for the next sunspot cycle: 2019-2030". The Huffington Post. Retrieved 22 November 2017.
  3. ^ a b McIntosh, Scott W.; Wang, Xin; Leamon, Robert J.; Davey, Alisdair R.; Howe, Rachel; Krista, Larisza D.; Malanushenko, Anna V.; Markel, Robert S.; Cirtain, Jonathan W.; Gurman, Joseph B.; Pesnell, William D.; Thompson, Michael J. (8 August 2014). "Deciphering Solar magnetic activity: On the relationship between the sunspot cycle and the evolution of small magnetic features". The Astrophysical Journal. 792 (1): 12. arXiv:1403.3071. Bibcode:2014ApJ...792...12M. doi:10.1088/0004-637X/792/1/12. S2CID 118418019.
  4. ^ a b c Upton, Lisa A.; Hathaway, David H. (28 August 2018). "An updated solar cycle 25 prediction with AFT: The modern minimum". Geophysical Research Letters. 45 (16): 8091–8095. arXiv:1808.04868. Bibcode:2018GeoRL..45.8091U. doi:10.1029/2018GL078387. S2CID 118913702.
  5. ^ Kitiashvili et al.[full citation needed]
  6. ^ a b c Bhowmik, Prantika; Nandy, Dibyendu (6 December 2018). "Prediction of the strength and timing of sunspot cycle 25 reveal decadal-scale space environmental conditions". Nature Communications. 9 (1): 5209. arXiv:1909.04537. Bibcode:2018NatCo...9.5209B. doi:10.1038/s41467-018-07690-0. PMC 6283837. PMID 30523260.
  7. ^ a b Li, F.Y.; Kong, D.F.; Xie, J.L.; Xiang, N.B.; Xu, J.C. (December 2018). "Solar cycle characteristics and their application in the prediction of cycle 25". Journal of Atmospheric and Solar-Terrestrial Physics. 181: 110–115. Bibcode:2018JASTP.181..110L. doi:10.1016/j.jastp.2018.10.014.
  8. ^ a b Sarp, V; Kilcik, A; Yurchyshyn, V; Rozelot, J P; Ozguc, A (December 2018). "Prediction of solar cycle 25: a non-linear approach". Monthly Notices of the Royal Astronomical Society. 481 (3): 2981–2985. Bibcode:2018MNRAS.481.2981S. doi:10.1093/mnras/sty2470.
  9. ^ McIntosh, Scott W.; Chapman, Sandra C.; Leamon, Robert J.; Egeland, Ricky; Watkins, Nicholas W. (2020-06-26). "Overlapping Magnetic Activity Cycles and the Sunspot Number: Forecasting Sunspot Cycle 25 Amplitude". Solar Physics. 295 (12): 163. arXiv:2006.15263. Bibcode:2020SoPh..295..163M. doi:10.1007/s11207-020-01723-y. S2CID 220250556.
  10. ^ Zharkova, V. V.; Shepherd, S. J.; Zharkov, S. I.; Popova, E. (4 March 2020). "Retraction Note: Oscillations of the baseline of solar magnetic field and solar irradiance on a millennial timescale". Scientific Reports. 10 (1): 4336. Bibcode:2020NatSR..10.4336Z. doi:10.1038/s41598-020-61020-3. PMC 7055216. PMID 32132618.
  11. ^ "Solar Cycle 25 Forecast Update | NOAA / NWS Space Weather Prediction Center".
  12. ^ Shepherd, Simon J.; Zharkov, Sergei I.; Zharkova, Valentina V. (13 October 2014). "Prediction of solar activity from solar background magnetic field variations in cycles 21–23". The Astrophysical Journal. 795 (1): 46. Bibcode:2014ApJ...795...46S. doi:10.1088/0004-637X/795/1/46. hdl:10454/10790.
  13. ^ "Scientists predict a new solar cycle is about to begin and that it might be stronger than the last one". Washington Post. 11 April 2019.
  14. ^ "Solar activity forecast for next decade favorable for exploration". NASA Ames. 12 June 2019.
  15. ^ "SOLAR CYCLE 25 FORECAST UPDATE". SPACE WEATHER PREDICTION CENTER - NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION. 9 December 2019.
  16. ^ "Maverick astrophysicist calls for unusually intense solar cycle, straying from consensus view". The Washington Post. 19 December 2020.
  17. ^ "Coronal hole faces Earth". Space Weather Live. Retrieved 24 April 2018.
  18. ^ a b Phillips, Tony (20 November 2018). "A sunspot from the next solar cycle". SpaceWeather.com. Retrieved 13 December 2018.
  19. ^ "Cycle 25 observations in SDO HMI imagery". Retrieved 2018-05-04.
  20. ^ Hudson, Hugh (10 April 2018). "A sunspot from cycle 25 for sure". RHESSI project. Retrieved 22 November 2018.
  21. ^ "www.nso.edu Do we see a dawn of solar cycle 25?". www.nso.edu/blog. 25 November 2019. Retrieved 2019-11-26.
  22. ^ "Spaceweather.com Time Machine". spaceweather.com. Retrieved 2019-12-26.
  23. ^ Nandy, Dibyendu; Bhatnagar, Aditi; Pal, Sanchita (2 March 2020). "Sunspot Cycle 25 is Brewing: Early Signs Herald its Onset". Research Notes of the AAS. 4 (2): 30. Bibcode:2020RNAAS...4...30N. doi:10.3847/2515-5172/ab79a1.
  24. ^ Pevtsov, Alexei A.; Bertello, Luca; Nagovitsyn, Yury A.; Tlatov, Andrey G.; Pipin, Valery V. (22 January 2021). "Long-term studies of photospheric magnetic fields on the Sun". J. Space Weather Space Clim. 11: 4. Bibcode:2021JSWSC..11....4P. doi:10.1051/swsc/2020069.
  25. ^ Pevtsov, Alexei (13 March 2021). "Time vs. solar latitude diagram of the radial component of the solar magnetic field (supersynoptic map of "butterfly" diagram". Retrieved 2021-03-13.
  26. ^ "Aurora and solar activity archive". spaceweatherlive. Retrieved 10 December 2020.
  27. ^ "M4.44 solar flare". www.spaceweatherlive.com. spaceweatherlive. 29 November 2020. Retrieved 10 December 2020.
  28. ^ "Earth-directed coronal mass ejection". www.spaceweatherlive.com. spaceweatherlive. Retrieved 10 December 2020.
  29. ^ Meteorologist, Derek Van Dam, CNN (9 December 2020). "Sun launches explosion of electromagnetic energy towards Earth: Geomagnetic Storm Watch issued". CNN. CNN. Retrieved 10 December 2020.
  30. ^ "Aurora and solar activity archive". spaceweatherlive. Retrieved 23 February 2021.
  31. ^ "First X-class solar flare of Solar Cycle 25". www.spaceweatherlive.com. Space Weather Live. 3 July 2021. Retrieved 4 July 2021.
  32. ^ "Solar max might come a bit early". Space weather.
  33. ^ "Geomagnetic Storm: Solar Eruption Arrives at Earth". SciTechDaily. Retrieved October 17, 2021.
  34. ^ a b Space https://www.space.com/sun-unleashes-major-x-class-solar-flare-october-2021. Retrieved October 28, 2021. {{cite web}}: Missing or empty |title= (help)
  35. ^ "The aurora and solar activity archive - October 2021". space weather live. Retrieved 13 November 2021.
  36. ^ "Viewing archive of Thursday, 4 November 2021". space weather live. Retrieved 13 November 2021.

External links[edit]