{"id": "dang2022_xgboostdl", "authors": "Dang Y., Chen Z., Li H., Shu H.", "title": "A Comparative Study of non-deep Learning, Deep Learning, and Ensemble Learning Methods for Sunspot Number Prediction", "venue": "Applied Artificial Intelligence 36(1) (2022)", "doi_or_url": "10.1080/08839514.2022.2074129", "issued_date": "2022-03", "date_basis": "arXiv v1 2203.05757", "amp_value": "164.62", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "164.62 in November 2035 for Solar Cycle 26", "sn_version": "unstated", "smoothing": "unstated", "tmax_value": "2035-11", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "XGBoost-DL ensemble. C25 forecast 133.47 (May 2025). Abstract cites a 'NASA' C26 value 161.2 Dec 2034 (not their own)."}
{"id": "asikainen2023_evenodd", "authors": "Asikainen T., Mantere J.", "title": "Prediction of even and odd sunspot cycles", "venue": "J. Space Weather Space Clim. 13, 4 (2023)", "doi_or_url": "10.1051/swsc/2023024", "issued_date": "2023-09", "date_basis": "arXiv v1 2309.04208 (journal 2023)", "amp_value": "", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "The median of the results implies that cycle 26 would be even slightly stronger than cycle 25 ... the probability that cycle 26 will be weaker than cycle 25 is only about 19%", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "", "method_class": "other_precursor", "qualitative": "stronger than C25 (large uncertainty)", "source_checked": "fulltext", "notes": "C26 via 13-mo SSN 41 months before minimum (even-cycle precursor) applied to their predicted C25 curve (C25 forecast 171±23), Monte Carlo 1e4 runs; median shown only in histogram (Fig. 14), no number in text. P(C26<C24)=0.8%. sn_version v2 inferred (2023 paper)."}
{"id": "liu2023_lstm_naoj", "authors": "Liu X., Zeng S., Deng L. et al.", "title": "Predicting the 25th and 26th solar cycles using the long short-term memory method", "venue": "PASJ 75(3), 691 (2023)", "doi_or_url": "10.1093/pasj/psad029", "issued_date": "2023-05", "date_basis": "journal online date (OpenAlex)", "amp_value": "135.0", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "SC 26 will be similar to SC 25 and reach its peak of 135.0 in 2035 January", "sn_version": "unstated", "smoothing": "unstated", "tmax_value": "2035-01", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "LSTM on NAOJ monthly relative sunspot numbers (not SILSO), so scale may differ from SILSO v2."}
{"id": "kalkan2023_narx", "authors": "Kalkan M.Y., Fawzy D.E., Saygac A.T.", "title": "Predictions of solar activity cycles 25 and 26 using non-linear autoregressive exogenous neural networks", "venue": "MNRAS 523(1), 1175 (2023)", "doi_or_url": "10.1093/mnras/stad1460", "issued_date": "2023-05", "date_basis": "journal online date (OpenAlex)", "amp_value": "113.25", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "RSSN = 116.6 (February 2025) and RSSN = 113.25 (October 2036), respectively", "sn_version": "unstated", "smoothing": "13mo_smoothed", "tmax_value": "2036-10", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "NARX neural net with multiple activity indicators; 'monthly averaged smoothed' SSN. C25 forecast 116.6."}
{"id": "moustafa2023_hybrid", "authors": "Moustafa S.S.R., Khodairy S.S.", "title": "Comparison of different predictive models and their effectiveness in sunspot number prediction", "venue": "Physica Scripta 98, 045022 (2023)", "doi_or_url": "10.1088/1402-4896/acc21a", "issued_date": "2023-03", "date_basis": "journal online date (OpenAlex)", "amp_value": "164.3", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "164.3 for Solar Cycle 26 in December 2034", "sn_version": "unstated", "smoothing": "unstated", "tmax_value": "2034-12", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "Hybrid LSTM/ARIMA/SARIMA model; C25 forecast 137.04 (Sep 2024)."}
{"id": "luo2024_phasesimilar", "authors": "Luo P., Tan B.", "title": "Long-term Evolution of Solar Activity and Prediction of the Following Solar Cycles", "venue": "Research in Astronomy and Astrophysics 24, 035016 (2024)", "doi_or_url": "10.1088/1674-4527/ad1ed2", "issued_date": "2024-01", "date_basis": "journal online 2024-01-15 (arXiv 2402.13173 later)", "amp_value": "133.0", "amp_low": "129.8", "amp_high": "136.2", "interval_meaning": "unstated", "quote": "reach its maximum between 2035 and 2036, with maximum ASN of about 133.0 ± 3.200", "sn_version": "unstated", "smoothing": "yearly_mean", "tmax_value": "2035.5", "method_class": "spectral", "qualitative": "", "source_checked": "abstract", "notes": "Annual average relative sunspot number (ASN), 104-yr century cycle + phase-similar method. Tmax stated as 2035-2036. C25 forecast 146.7±33.4. Note tiny ±3.2."}
{"id": "rodriguez2024_polarflux_ml", "authors": "Rodríguez J.-V., Carrasco V.M.S., Rodríguez-Rodríguez I. et al.", "title": "Predicting Solar Cycle 26 Using the Polar Flux as a Precursor, Spectral Analysis, and Machine Learning", "venue": "Solar Physics 299 (2024)", "doi_or_url": "10.1007/s11207-024-02361-4", "issued_date": "2024-08", "date_basis": "journal publication month (OpenAlex)", "amp_value": "121.2", "amp_low": "111.2", "amp_high": "131.2", "interval_meaning": "rmse", "quote": "131.4 (in July 2024) and 121.2 (in September 2034) for Solar Cycles 25 and 26, respectively, with a root mean square error of 10.0", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "2034-09", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "Multivariate ML + FFT spectral with polar flux as input; low/high = value ± RMSE. Companion polar-flux precursor estimate recorded separately."}
{"id": "rodriguez2024_polarflux_precursor", "authors": "Rodríguez J.-V., Carrasco V.M.S., Rodríguez-Rodríguez I. et al.", "title": "Predicting Solar Cycle 26 Using the Polar Flux as a Precursor, Spectral Analysis, and Machine Learning", "venue": "Solar Physics 299 (2024)", "doi_or_url": "10.1007/s11207-024-02361-4", "issued_date": "2024-08", "date_basis": "journal publication month (OpenAlex)", "amp_value": "126.9", "amp_low": "92.7", "amp_high": "161.1", "interval_meaning": "unstated", "quote": "142.3 ± 34.2 and 126.9 ± 34.2 for Cycles 25 and 26, respectively", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "", "method_class": "polar_field_precursor", "qualitative": "", "source_checked": "abstract", "notes": "Second method in same paper (polar flux precursor regression). C25 value 142.3±34.2."}
{"id": "rodriguez2024_hemispheric", "authors": "Rodríguez J.-V., Carrasco V.M.S. et al.", "title": "Hemispheric Sunspot Number Prediction for Solar Cycles 25 and 26 Using Spectral Analysis and Machine Learning", "venue": "Solar Physics 299 (2024)", "doi_or_url": "10.1007/s11207-024-02363-2", "issued_date": "2024-08", "date_basis": "journal publication month (OpenAlex)", "amp_value": "", "amp_low": "", "amp_high": "", "interval_meaning": "rmse", "quote": "51.5 in November 2033 ... (root mean square error of 6.1) ... 70.1 in November 2034 ... (root mean square error of 6.8)", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "2034-11", "method_class": "ml_neural", "qualitative": "both hemispheres lower than C25", "source_checked": "abstract", "notes": "Hemispheric only: North 51.5 (Nov 2033, RMSE 6.1), South 70.1 (Nov 2034, RMSE 6.8). Total not stated in abstract (naive sum of peaks 121.6, but peaks non-simultaneous; not recorded as amp). tmax given = southern peak."}
{"id": "rodriguez2024_gleissberg_ml", "authors": "Rodríguez J.-V., Carrasco V.M.S. et al.", "title": "Are we crossing a minimum of the Gleissberg centennial cycle? Multivariate machine learning-based prediction of the sunspot number using different proxies of solar activity and spectral analysis", "venue": "Advances in Space Research (2024)", "doi_or_url": "10.1016/j.asr.2024.08.033", "issued_date": "2024-08", "date_basis": "journal online 2024-08-14", "amp_value": "115.4", "amp_low": "105.6", "amp_high": "125.2", "interval_meaning": "rmse", "quote": "maximum values of 134.2 (in June 2024) and 115.4 (in May 2034), respectively, with a root mean squared error (RMSE) of 9.8", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "2034-05", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "Multivariate ML with several activity proxies + spectral analysis; low/high = value ± RMSE."}
{"id": "pishkalo2025_oddeven", "authors": "Pishkalo M.I.", "title": "Predicted amplitude of the next solar cycle 26 using the strength of current solar cycle 25", "venue": "Kosmichna Nauka i Tekhnologiya 31(5), 50 (2025)", "doi_or_url": "10.15407/knit2025.05.050", "issued_date": "2025-10", "date_basis": "journal publication date (OpenAlex)", "amp_value": "142.2", "amp_low": "89.5", "amp_high": "194.9", "interval_meaning": "1sigma", "quote": "we obtain the maximum of the next Solar Cycle 26 equal to 142.2 ± 52.7 (the 70 % confidence interval)", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "", "method_class": "even_odd_rule", "qualitative": "higher than C24, lower than C25", "source_checked": "fulltext", "notes": "Odd-even (Gnevyshev-Ohl-type) regression using C25 amplitude 160.8 (Oct 2024, which is the SILSO v2 13-mo value). Also gives C27 = 188.4. Interval stated as 70% confidence interval (coded 1sigma). Alternate fit excluding cycle pairs (7,8),(1,2): 131.9 ± 49.5. Uses SILSO v2 smoothed monthly. Table 1 of this paper compiles other C26 forecasts."}
{"id": "abdelrahman2026_prophet", "authors": "Abdel Rahman H.I., Badawy W.A.", "title": "Forecasting the number of sunspots for solar cycle 25 utilizing the facebook prophet model", "venue": "Scientific Reports (2026)", "doi_or_url": "10.1038/s41598-025-33819-5", "issued_date": "2026-01", "date_basis": "journal online 2026-01-14", "amp_value": "118", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "Solar Cycle 26 will peak in mid-2034, both with a smoothed sunspot number of approximately 118", "sn_version": "unstated", "smoothing": "13mo_smoothed", "tmax_value": "2034.5", "method_class": "statistical_timeseries", "qualitative": "", "source_checked": "abstract", "notes": "FB Prophet on 1749-2025 data; forecast covers only early part of C26 through 2036. C25 forecast also ~118 (observed ~160)."}
{"id": "duan2026_mtspnet", "authors": "Duan Z., Wang R. et al.", "title": "MTSP-Net: A Multimodal Time Series Prediction Network for Solar Cycle Forecasting", "venue": "Research in Astronomy and Astrophysics (2026)", "doi_or_url": "10.1088/1674-4527/ae4e12", "issued_date": "2026-03", "date_basis": "journal online 2026-03-05", "amp_value": "158.45", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "the peak value is predicted to be 158.45 in 2034 April", "sn_version": "unstated", "smoothing": "unstated", "tmax_value": "2034-04", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "Multimodal deep network."}
{"id": "kalkan2026_ml", "authors": "Kalkan M.Y., Fawzy D.E., Manfred C. et al.", "title": "Forecasting Solar Cycle 26 with Multiple Machine Learning Techniques", "venue": "PASP (2026)", "doi_or_url": "10.1088/1538-3873/ae541c", "issued_date": "2026-04", "date_basis": "journal publication (OpenAlex)", "amp_value": "109", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "the expected solar peak in terms of sunspot numbers (11 yr, monthly averaged) of SC 26 is 109 (2034 July)", "sn_version": "unstated", "smoothing": "unstated", "tmax_value": "2034-07", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "Multiple ML models plus Waldmeier-effect constraint. Same group's 2023 NARX gave 113.25."}
{"id": "ye2026_multiscale", "authors": "Ye D., Li H., Guo L., Ji X. et al.", "title": "Applicability of Sunspot Number Prediction Across Multiple Timescales Based on Different Models", "venue": "PASP (2026)", "doi_or_url": "10.1088/1538-3873/ae75f4", "issued_date": "2026-06", "date_basis": "journal publication (OpenAlex)", "amp_value": "156.85", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "solar cycle 26 will reach its maximum in 2035 February with a peak of 156.85", "sn_version": "unstated", "smoothing": "unstated", "tmax_value": "2035-02", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "Comparison of models across timescales; the long-term C26 forecast from the selected deep model."}
{"id": "abdelrahman2026_arfima", "authors": "Abdel Rahman H.I., Eid D.", "title": "Long-memory modeling and forecasting of monthly mean sunspot numbers for cycles 25 & 26 using ARFIMA", "venue": "Scientific Reports (2026)", "doi_or_url": "10.1038/s41598-026-56468-8", "issued_date": "2026-06", "date_basis": "journal online 2026-06-22", "amp_value": "179.3", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "a maximum ... of 224.7 for Solar Cycle 25 (observed peak: approximately 216 in August 2024) and 179.3 for Solar Cycle 26 around March 2035", "sn_version": "unstated", "smoothing": "monthly", "tmax_value": "2035-03", "method_class": "statistical_timeseries", "qualitative": "", "source_checked": "abstract", "notes": "ARFIMA on monthly MEAN (unsmoothed) SN 1749-Oct 2025; not directly comparable with 13-mo smoothed maxima (monthly peaks run higher)."}
{"id": "wu2021_tmlpe", "authors": "Wu S.-S., Qin G.", "title": "Predicting Sunspot Numbers for Solar Cycles 25 and 26", "venue": "arXiv 2102.06001 (ApJ 2021)", "doi_or_url": "https://arxiv.org/abs/2102.06001", "issued_date": "2021-02", "date_basis": "arXiv v1", "amp_value": "107.3", "amp_low": "62.3", "amp_high": "143.6", "interval_meaning": "95ci", "quote": "maximum of cycle 26 predicted by TMLP-E is 107.3 (95% CI is 62.3 −143.6)", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "", "method_class": "statistical_timeseries", "qualitative": "", "source_checked": "fulltext", "notes": "Two-cycle-ahead extension of ternary multiple linear precursor model (TMLP-E). Ascent 4.80 yr, length 10.97 yr. C25 forecast 115.1. sn_version v2 inferred from 2021 SILSO usage, not verified in text."}
{"id": "javaraiah2017_gleissberg", "authors": "Javaraiah J.", "title": "Will Solar Cycles 25 and 26 Be Weaker than Cycle 24?", "venue": "Solar Physics 292, 172 (2017)", "doi_or_url": "10.1007/s11207-017-1197-x", "issued_date": "2017-11", "date_basis": "arXiv v1 1711.04117 / journal Nov 2017", "amp_value": "", "amp_low": "7", "amp_high": "23", "interval_meaning": "range", "quote": "A best linear fit to the values of amplitudes (164.5, 158.5, 120.8, 81.9, 30 – 50) and times of Cycles 21 – 25 ... suggests 7 – 23 for the amplitude of Cycle 26", "sn_version": "v1", "smoothing": "13mo_smoothed", "tmax_value": "", "method_class": "statistical_timeseries", "qualitative": "C25 and C26 almost same strength, weaker than C24", "source_checked": "fulltext", "notes": "Cosine fit to Gleissberg modulation + linear trend extrapolation; C25 predicted 30-50 (v1), badly wrong. Amplitudes in v1 scale."}
{"id": "edmonds2025_spectral", "authors": "Edmonds I., Killen P.", "title": "Combining spectral analysis and narrow band pass filtering to predict solar cycles", "venue": "arXiv 2510.14355", "doi_or_url": "https://arxiv.org/abs/2510.14355", "issued_date": "2025-10", "date_basis": "arXiv v1", "amp_value": "50", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "Predicted SSN amplitudes for cycles 26 and 28 are about 50 ... the forecast amplitude of solar cycle 26 is 174/4 = 44", "sn_version": "unstated", "smoothing": "unstated", "tmax_value": "", "method_class": "spectral", "qualitative": "Maunder-like grand minimum 2030-2110", "source_checked": "fulltext", "notes": "Abstract says ~50; body computes 44 from trough-peak scaling to C23. Text also mentions Cao et al. 2024 Transformer model giving ~50 and another model ~120."}
{"id": "bilenko2026_gmf", "authors": "Bilenko I.A.", "title": "Influence of local and global solar magnetic fields on medium-term forecasting of the number and parameters of coronal mass ejections", "venue": "arXiv 2607.18971", "doi_or_url": "https://arxiv.org/abs/2607.18971", "issued_date": "2026-07", "date_basis": "arXiv v1", "amp_value": "", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "Assuming, following (Gerc.eker 2025), that cycle 26 will be close in its parameters to cycle 20", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "2034.5", "method_class": "other", "qualitative": "similar to Cycle 20 (analog)", "source_checked": "fulltext", "notes": "Global-magnetic-field reversal timing: C26 min CR 2375±5, max between CR 2406.5-2433.5 (approx. 2033.5-2035.5 by my CR conversion), length 11.28 yr. Amplitude taken as C20 contour (C20 v2 max 156.6) - no explicit number stated, not recorded. Title truncated."}
{"id": "wang_zf2026_sft_polar", "authors": "Wang Z.-F., Jiang J., Luo Y., Wang R. et al.", "title": "The Recent Anomalously Weak Polar Field Does Not Imply a Weak Field at Solar Cycle 25 Minimum", "venue": "ApJL (2026)", "doi_or_url": "10.3847/2041-8213/ae8765", "issued_date": "2026-07", "date_basis": "arXiv v1 2607.03178 (journal 2026-07-21)", "amp_value": "158", "amp_low": "113", "amp_high": "203", "interval_meaning": "1sigma", "quote": "If we adopt the linear relationship by Jiang et al. (2018), i.e., S n+1 = 58.7Dn, the amplitude of cycle 26 is 158±45", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "", "method_class": "flux_transport_or_dynamo", "qualitative": "even chance stronger or weaker than C25; unlikely exceptionally weak", "source_checked": "fulltext", "notes": "SFT simulation with predicted AR emergence to get axial dipole at C25 minimum, then dipole-amplitude precursor (polar_field_precursor + SFT). Authors call it 'preliminary estimation'; ±45 treated as 1sigma (text refers to 1σ range). Excludes precursor-method uncertainty."}
{"id": "wang_r2026_polar2026", "authors": "Wang R., Jiang J., Luo Y.", "title": "Prediction of the Solar Polar Fields in 2026: An Unusually Weak Level across the Last Five Cycles", "venue": "ApJ (2026)", "doi_or_url": "10.3847/1538-4357/ae4d38", "issued_date": "2025-12", "date_basis": "arXiv v1 2512.17359", "amp_value": "", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "raising concerns about the polar-field strength at the cycle 25/26 minimum and the amplitude of cycle 26", "sn_version": "", "smoothing": "", "tmax_value": "", "method_class": "flux_transport_or_dynamo", "qualitative": "concern C26 may be weak; polar field at minimum 'remains highly uncertain'", "source_checked": "fulltext", "notes": "SFT prediction of 2026 polar fields (weakest of last five cycles at same phase); no C26 amplitude number. Superseded in part by Wang Z.-F. et al. 2026 ApJL (158±45)."}
{"id": "chapman2026_clock", "authors": "Chapman S.C.", "title": "A New Declining Phase Precursor and an Early Prediction of Cycle 26 Maximum", "venue": "ApJ 1003, 159 (2026)", "doi_or_url": "10.3847/1538-4357/ae6859", "issued_date": "2026-03", "date_basis": "received 2026-03-10 (ApJ 1003, 159; published 2026-05); open copy WRAP Warwick", "amp_value": "", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "The SSN projections give predictions for the cycle 26 maximum that are consistent with each other and suggest a weak-to-moderate cycle 26 maximum, weaker than cycle 25", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "", "method_class": "other_precursor", "qualitative": "weak-to-moderate; <= C25 (C25 max 160.9)", "source_checked": "fulltext", "notes": "Hilbert-transform solar-cycle clock; C26 max regressed on 13-mo SSN at C25 switch-off (gradient ~3). C25 switch-off projected via NOAA [2029.16, SSN 31], McIntosh 2023 [2028.88, 23], NMSC [2029.15, 31]; resulting C26 maxima only shown graphically (Fig. 5), no number in text. Firm prediction once switch-off is passed (~2028-2029)."}
{"id": "soman2025_dtw_preprint", "authors": "Soman V., Sabarinath A.", "title": "Analog-Based Forecasting of Solar Cycles Using Dynamic Time Warping and Residual Bootstrapping: Real-Time Application to Cycle 25 (preprint v1)", "venue": "Research Square preprint", "doi_or_url": "10.21203/rs.3.rs-7526100/v1", "issued_date": "2025-09", "date_basis": "preprint posted 2025-09-16 (Crossref)", "amp_value": "151.66", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "SC26 peak $151.66$ at month $42$ (length $129$ months)", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "", "method_class": "statistical_timeseries", "qualitative": "", "source_checked": "abstract", "notes": "DTW historical-analog method, frozen pre-cycle snapshot. Peak at month 42 after C26 onset. C25 baseline 193.86. Superseded by journal version (separate record)."}
{"id": "soman2026_dtw_soph", "authors": "Soman V., Sabarinath A.", "title": "Analog-Based Forecasting of Solar Cycles Using Dynamic Time Warping and Residual Bootstrapping: Real-Time Application to Cycle 25", "venue": "Solar Physics 301, 86 (2026)", "doi_or_url": "10.1007/s11207-026-02686-2", "issued_date": "2026-06", "date_basis": "journal online 2026-06-04 (Crossref); preprint 2025-09", "amp_value": "143.3", "amp_low": "119.2", "amp_high": "173.2", "interval_meaning": "unstated", "quote": "Solar Cycles 18 and 22 give a predicted maximum of 143.3 smoothed sunspots at elapsed month 41 ... differs from the 119.2–173.2 interval reported previously", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "", "method_class": "statistical_timeseries", "qualitative": "", "source_checked": "fulltext", "notes": "Numbers taken from the authors' follow-up preprint (10.21203/rs.3.rs-10909546/v1, 2026-09), which restates the SoPh 2026 analog baseline (C18+C22 analogs) and its interval; journal text itself not seen (Springer blocked). The follow-up recomputes a nominal 80% range 110.2-191.0 and states its integrated precursor-analog method 'does not currently provide a Solar Cycle 26 forecast'."}
{"id": "zermane2025_msoda", "authors": "Zermane M.A., Oulebsir N., Bekli M.R., Belhadi Z., Becheker K., Zaidi A., Hadj Hammou A.", "title": "Magnitude Prediction of Solar Cycle 26 Using a New Precursor Approach", "venue": "Solar Physics 300, 53 (2025)", "doi_or_url": "10.1007/s11207-025-02459-3", "issued_date": "2024-06", "date_basis": "received 2024-06-09 (online 2025-04-08), per web search snippet", "amp_value": "109.14", "amp_low": "76.22", "amp_high": "142.06", "interval_meaning": "unstated", "quote": "109.14 ± 32.92 in 2035.3 ± 2.3 (MSODA)", "sn_version": "v2", "smoothing": "unstated", "tmax_value": "2035.3", "method_class": "polar_field_precursor", "qualitative": "", "source_checked": "abstract", "notes": "Modified SODA (Schatten-Pesnell solar dynamo amplitude: polar field + solar flux precursor) with ~100-yr modulation and 'minimal fluctuation method'. Numbers verified via Pishkalo 2025 Table 1 (fulltext) and a web-search summary of the ADS abstract; journal text not seen. Authors favour MXSODA (separate record). sn_version v2 inferred (SILSO data)."}
{"id": "zermane2025_mxsoda", "authors": "Zermane M.A., Oulebsir N., Bekli M.R., Belhadi Z., Becheker K., Zaidi A., Hadj Hammou A.", "title": "Magnitude Prediction of Solar Cycle 26 Using a New Precursor Approach", "venue": "Solar Physics 300, 53 (2025)", "doi_or_url": "10.1007/s11207-025-02459-3", "issued_date": "2024-06", "date_basis": "received 2024-06-09 (online 2025-04-08), per web search snippet", "amp_value": "160.70", "amp_low": "112.87", "amp_high": "208.53", "interval_meaning": "unstated", "quote": "160.70 ± 47.83 in 2035.3 ± 2.3 (MXSODA)", "sn_version": "v2", "smoothing": "unstated", "tmax_value": "2035.3", "method_class": "polar_field_precursor", "qualitative": "", "source_checked": "abstract", "notes": "Extended SODA (XSODA) + century modulation; described as the most reliable indicator by the authors (per search summary). Numbers verified via Pishkalo 2025 Table 1."}
{"id": "zeng2025_lstmfcn", "authors": "Zeng S., Zhu S., Huang Y., Zeng X., Zheng S., Deng L.", "title": "Prediction of solar cycles 26 and 27 based on LSTM-FCN", "venue": "New Astronomy 117, 102353 (2025)", "doi_or_url": "10.1016/j.newast.2025.102353", "issued_date": "2025-01", "date_basis": "journal online 2025-01-11", "amp_value": "194.4", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "Zeng et al., 2025 [15] 194.4 in June 2034 (quoted in Pishkalo 2025 Table 1)", "sn_version": "unstated", "smoothing": "unstated", "tmax_value": "2034-06", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "SECONDARY: value from Pishkalo 2025 (KNIT) Table 1; original abstract not retrieved (Elsevier). Also forecasts C27."}
{"id": "cao2024_informer", "authors": "Cao J., Xu T., Deng L., Zhou X. et al.", "title": "An Improved Prediction of Solar Cycles 25 and 26 Using the Informer Model: Gnevyshev Peaks and North-South Asymmetry", "venue": "ApJ 969 (2024)", "doi_or_url": "10.3847/1538-4357/ad4551", "issued_date": "2024-07", "date_basis": "journal publication month (OpenAlex)", "amp_value": "133.4", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "133.4 in May 2036 (Informer model) (quoted in Pishkalo 2025 Table 1)", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "2036-05", "method_class": "ml_neural", "qualitative": "double (Gnevyshev) peak with higher second peak", "source_checked": "abstract", "notes": "SECONDARY for number: from Pishkalo 2025 Table 1 (Edmonds & Killen 2025 paraphrase as 'about 120'). Abstract (seen) gives no number. Uses SILSO whole-disk 1749-2023 + hemispheric SSN. Hemispheric forecasts also made. CONFLICTING secondary reports: web-search fragments of the full text give Informer double peaks (unsmoothed first peak 146.1 Jan 2034; smoothed first peak 117.6 Feb 2034, second peak 2036 value not seen); another later paper cites Cao 2024 as 132.30 (Feb 2035). 133.4 (May 2036) is probably the smoothed second Gnevyshev peak. Needs full-text check (IOP blocked)."}
{"id": "cao2024_transformer", "authors": "Cao J., Xu T., Deng L., Zhou X. et al.", "title": "An Improved Prediction of Solar Cycles 25 and 26 Using the Informer Model: Gnevyshev Peaks and North-South Asymmetry", "venue": "ApJ 969 (2024)", "doi_or_url": "10.3847/1538-4357/ad4551", "issued_date": "2024-07", "date_basis": "journal publication month (OpenAlex)", "amp_value": "65.8", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "65.8 in January 2037 (Transformer model) (quoted in Pishkalo 2025 Table 1)", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "2037-01", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "SECONDARY: comparison Transformer model in the same paper (authors prefer Informer). Edmonds & Killen 2025 paraphrase as 'about 50'. Web-search fragments: smoothed Transformer peaks 57.4 (May 2034) and 65.8 (2037), consistent with Pishkalo."}
{"id": "petrovay2024_parametric", "authors": "Petrovay K. et al.", "title": "Predicting Solar Cycles with a Parametric Time Series Model", "venue": "Universe 10(9), 364 (2024)", "doi_or_url": "10.3390/universe10090364", "issued_date": "2024-09", "date_basis": "journal online (Crossref created 2024-09-11)", "amp_value": "96.9", "amp_low": "71.8", "amp_high": "122.0", "interval_meaning": "unstated", "quote": "Our predictions for the amplitudes of SC25, SC26, and SC27 are 155.8±20.7, 96.9±25.1 and 140.8±20.7, respectively", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "", "method_class": "statistical_timeseries", "qualitative": "weaker than C24; weakest since Dalton Minimum", "source_checked": "abstract", "notes": "Parametric (cycle-shape parameter) time-series model. C25 forecast 155.8±20.7 (close to observed 160.9). sn_version/smoothing inferred, not verified. Author list from citation 'Petrovay K.'; co-authors not checked."}
{"id": "gerceker2025_simplex", "authors": "Gerçeker K., Kilcik A., Ozguc A., Yurchyshyn V.", "title": "Simplex Projection Predictions of the Remainder of Solar Cycle 25 and the Next Solar Cycle 26 Based on the Monthly Mean Sunspot Numbers", "venue": "Solar Physics 300, 169 (2025)", "doi_or_url": "10.1007/s11207-025-02577-y", "issued_date": "2025-11", "date_basis": "journal online 2025-11-26", "amp_value": "", "amp_low": "137.4", "amp_high": "146.2", "interval_meaning": "range", "quote": "maximum is predicted for June 2035 with 150.6–181.5 monthly mean SSN (13-month smoothed 137.4–146.2) [web-search paraphrase of abstract]", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "2035-06", "method_class": "statistical_timeseries", "qualitative": "slightly weaker than C25, stronger than C24; double or flat peak resembling C20", "source_checked": "abstract", "notes": "Simplex projection (nonlinear time-series/empirical dynamic modelling) on monthly mean SSN. Monthly-mean range 150.6-181.5; recorded low/high are the 13-mo smoothed equivalents. Numbers from web-search summary of Springer abstract (direct page blocked) - verify. C25 minimum mid-2030, C26 min late 2040."}
{"id": "nasa_msfc_msafe_meancycle", "authors": "NASA MSFC Natural Environments Branch (MSAFE)", "title": "Estimates of 13-month smooth solar activity for balance of Cycle 25 with a mean cycle given for Cycle 26 (Table 4, Oct 2026 release)", "venue": "NASA Solar Cycle Progression and Forecast (monthly)", "doi_or_url": "https://www.nasa.gov/wp-content/uploads/2026/10/oct2026ssn-prd.txt", "issued_date": "2022-03", "date_basis": "same C26 peak (161.2, Dec 2034) already cited by Dang et al. arXiv 2203.05757 (2022-03); re-checked in Oct 2026 table", "amp_value": "161.2", "amp_low": "60.3", "amp_high": "276.2", "interval_meaning": "2sigma", "quote": "2034.917 DEC 276.2 161.2 60.3 (95% / 50% / 5% percentiles)", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "2034-12", "method_class": "other", "qualitative": "", "source_checked": "fulltext", "notes": "AGENCY. Not a physical forecast: C26 is a statistical MEAN-CYCLE template for engineering use; NASA states MSFC cannot predict the next cycle yet. 5-95 percentile band described by NASA as approx ±2 sigma. 50% minimum Nov 2030 (6.7). Cited as 'NASA prediction' by Dang 2022 and Abdel Rahman & Eid 2026. sn_version v2 assumed (SILSO input)."}
{"id": "miesch2025_noaa_prelim", "authors": "Miesch M.S. et al. (NOAA SWPC / CIRES)", "title": "Solar Cycle Prediction at NOAA's Space Weather Prediction Center", "venue": "Space Weather (2025)", "doi_or_url": "10.1029/2025SW004444", "issued_date": "2025-06", "date_basis": "first published 2025-06-11", "amp_value": "", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "it is important to emphasize that the Cycle 26 prediction in Figure 15 is not intended as a prediction for the maximum value of the SSNV2 and the corresponding date", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "", "method_class": "statistical_timeseries", "qualitative": "probabilistic P(S|t) curve, no maximum forecast; reference average cycle Smax=183, start 11/2030", "source_checked": "fulltext", "notes": "AGENCY (NOAA SWPC). Preliminary probabilistic C26 prediction based on cycle-length/next-amplitude statistics; gives 50%/95% bands of SSN vs date, explicitly not a cycle-max prediction. SWPC web page (2026) states 'We do not yet produce a prediction for Solar Cycle 26'. Average cycle (C6-24) Smax 183 shown only for comparison."}
{"id": "kumar2024_vd2r2w", "authors": "Kumar V.", "title": "Enhancing Solar Cycle 25 and 26 Forecasting with Vipin-Deep-Decomposed-Recomposed Rolling-Window (vD2R2w) Model on Sunspot Number Observations", "venue": "Solar Physics 299(10), 147 (2024)", "doi_or_url": "10.1007/s11207-024-02389-6", "issued_date": "2024-10", "date_basis": "journal online (Crossref created 2024-10-23)", "amp_value": "191.71", "amp_low": "148.34", "amp_high": "235.08", "interval_meaning": "unstated", "quote": "SC25: 127.16 (± 6.83) in 2025 and SC26: 191.71 (± 43.37) in 2035 [web-search summary of abstract]", "sn_version": "unstated", "smoothing": "unstated", "tmax_value": "2035", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "Decomposition + deep learning rolling-window model. Number via web-search summary of Springer abstract (direct access blocked) - verify. C25 forecast 127.16±6.83."}
{"id": "kumar2025_hybridensemble", "authors": "Kumar A., Kumar V.", "title": "Hybrid-Ensemble Deep-Learning Models to Enhance the Sunspot Prediction and Forecasting of Solar Cycle 26", "venue": "Solar Physics 300, 100 (2025)", "doi_or_url": "10.1007/s11207-025-02510-3", "issued_date": "2025-07", "date_basis": "journal online 2025-07-17", "amp_value": "165.35", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "a peak in 2036 (SSN: 165.35), followed by a slight decline in 2037 (SSN: 155.25) [web-search summary of abstract]", "sn_version": "unstated", "smoothing": "yearly_mean", "tmax_value": "2036", "method_class": "ml_neural", "qualitative": "", "source_checked": "abstract", "notes": "Hybrid ensemble deep learning; forecasts given as yearly values (smoothing coded yearly_mean from year-resolution output; model also trained on 13-mo smoothed data). Abstract oddly says lowest SSN in 2032 (10.41). Number via web-search summary - verify."}
{"id": "javaraiah2024_ratio_130yr", "authors": "Javaraiah J.", "title": "Prediction of the amplitude of solar cycle 25 from the ratio of sunspot number to sunspot-group area, low latitude activity, and 130-year solar cycle", "venue": "Advances in Space Research (2024)", "doi_or_url": "https://arxiv.org/abs/2405.03441", "issued_date": "2024-05", "date_basis": "arXiv v1", "amp_value": "", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "The Solar Cycle 26 would be a small cycle and is expected to be similar as that of Solar Cycle 14 ... weak Solar Cycle 26 (weakest in 12 - 13 decades)", "sn_version": "v2", "smoothing": "13mo_smoothed", "tmax_value": "", "method_class": "other_precursor", "qualitative": "considerably smaller than C25; similar to C14; weakest in 12-13 decades", "source_checked": "fulltext", "notes": "Based on long-term variation of SN/sunspot-group-area ratio and ~130-yr cycle. C26 minimum predicted ~2032.21 (Mar 2032 ±6 mo). No numeric C26 amplitude (C14 v2 max ~107 for reference, not author's number). C25 predictions 127±26 and 141±19."}
{"id": "liu_wang2026_centennial", "authors": "Liu J.-J., Wang H.X.", "title": "A New Insight Into the Centennial Cycle Phase Similarity Model for Solar Activity", "venue": "Astronomische Nachrichten (2026)", "doi_or_url": "10.1002/asna.70143", "issued_date": "2026-09", "date_basis": "journal online 2026-09-29", "amp_value": "", "amp_low": "", "amp_high": "", "interval_meaning": "unstated", "quote": "attaining a peak maximum average of relative sunspot number value of approximately [number in formula]. ... our results align closely with the predictions of Luo & Tan, with an error of approximately 2.234%", "sn_version": "unstated", "smoothing": "yearly_mean", "tmax_value": "", "method_class": "spectral", "qualitative": "close to Luo & Tan 2024 (133.0 yearly)", "source_checked": "abstract", "notes": "All numbers in the abstract are rendered as formula images and missing from Crossref/OpenAlex text; full text (Wiley) not retrieved. Implied value ~130 or ~136 (2.234% from 133.0), NOT recorded as amp. Centennial-cycle phase-similarity model."}
{"id": "singh2019_simplex_trend", "authors": "Singh A.K., Bhargawa A.", "title": "Prediction of declining solar activity trends during solar cycles 25 and 26 and indication of other solar minimum", "venue": "Astrophysics and Space Science 364, 12 (2019)", "doi_or_url": "10.1007/s10509-019-3500-9", "issued_date": "2018-12", "date_basis": "received 2018-12-04 (published 2019-01-15), per web-search summary", "amp_value": "78", "amp_low": "71", "amp_high": "85", "interval_meaning": "unstated", "quote": "sunspot numbers of 89 ± 9 and 78 ± 7 [C25 / C26] ... Cycle 26 would start in March 2031, peak in June 2036 [web-search summary of abstract]", "sn_version": "unstated", "smoothing": "unstated", "tmax_value": "2036-06", "method_class": "statistical_timeseries", "qualitative": "weaker than C24 and C25; Dalton-like minimum", "source_checked": "abstract", "notes": "Simplex projection on trend component of SSN, F10.7, Lyman-alpha (1947-2017). C26 F10.7 peak 118±9. C25 forecast 89±9 (observed ~161). Numbers from web-search summary of Springer abstract - verify."}
{"id": "cao2024_ati_hemispheric", "authors": "Cao J., Xu T., Deng L., Zhou X. et al.", "title": "Hemispheric prediction of solar cycles 25 and 26 from multivariate sunspot time-series data via Informer models", "venue": "Astronomical Techniques and Instruments (2024)", "doi_or_url": "10.61977/ati2024047", "issued_date": "2024-11", "date_basis": "Crossref created 2024-11-11", "amp_value": "", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "the maximum amplitude of solar cycle 25 is higher than the previous solar cycle 24 and the following solar cycle 26 [web-search summary]", "sn_version": "unstated", "smoothing": "unstated", "tmax_value": "", "method_class": "ml_neural", "qualitative": "weaker than C25", "source_checked": "abstract", "notes": "Hemispheric Informer forecasts; numeric C26 values not retrieved (SciEngine page is JS-only, no Crossref abstract)."}
{"id": "zharkova2025_gsm", "authors": "Zharkova V.V., Zharkov S., Shepherd S.J.", "title": "Modern grand solar minimum and its impact on the terrestrial environment", "venue": "EGU General Assembly 2025, EGU25-20202 (abstract)", "doi_or_url": "10.5194/egusphere-egu25-20202", "issued_date": "2025-03", "date_basis": "EGU abstract 2025-03-15", "amp_value": "", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "the modern GSM started in 2020 and to last until 2053. This GSM leads to a reduction of solar irradiance by about 0.22% ... in the cycle 26", "sn_version": "", "smoothing": "", "tmax_value": "", "method_class": "flux_transport_or_dynamo", "qualitative": "very weak (Maunder-type grand minimum 2020-2053 spanning C25-C27)", "source_checked": "abstract", "notes": "PCA eigenvectors of background magnetic field interpreted as two dynamo waves; no SSN number for C26. Same framework predicted a weak C25, which was contradicted by C25 max 160.9. Method class coded as dynamo-type (two-layer dynamo-wave interpretation), though the forecast is a PCA/harmonic extrapolation."}
{"id": "velasco2021_ml_minimum", "authors": "Velasco Herrera V.M., Soon W., Legates D.R.", "title": "Does Machine Learning reconstruct missing sunspots and forecast a new solar minimum?", "venue": "Advances in Space Research 68 (2021)", "doi_or_url": "10.1016/j.asr.2021.03.023", "issued_date": "2021-03", "date_basis": "journal online 2021-03-30", "amp_value": "", "amp_low": "", "amp_high": "", "interval_meaning": "none", "quote": "our ML model forecasts a new phase of extended solar minima that began prior to Sunspot Cycle 24 (ca. 2008-2019) and will persist until Sunspot Cycle 27 (ca. 2050 or so)", "sn_version": "v2", "smoothing": "yearly_mean", "tmax_value": "", "method_class": "ml_neural", "qualitative": "weak (extended solar minimum through C27)", "source_checked": "abstract", "notes": "Bayesian ML on annual SN v2 (1700-2019). Explicit numbers only for C25 (annual peak 95, range 80-115; observed C25 annual ~155). No C26 number in abstract."}