Will the NSIDC Sea Ice Index report an average Northern Hemisphere sea ice extent of at least 7.05 million km² for October 2026?
échéance 2026-11-10
confiance moyenne
preuve niveau 1
44 %estimation Asturna
Critère de résolution
Resolves YES if the NSIDC Sea Ice Index v4 monthly file for the Northern Hemisphere (https://noaadata.apps.nsidc.org/NOAA/G02135/north/monthly/data/N_10_extent_v4.0.csv), read for the first time on or after 2026-11-10, shows an extent >= 7.05 million km² for October 2026 (region N). The value read at that moment is final; later revisions do not change the outcome. If the row is not yet published on 2026-11-10, the check is repeated until 2026-11-20, after which the question is voided. Also voided if NSIDC changes the dataset version or the definition of the monthly file. Reference at creation: average daily extent of the first five days of the month = 5.76 million km² (latest daily value 5.96 on 2026-10-06; daily values are an estimation aid only and never decide). Data: NSIDC Sea Ice Index, Version 4 (NOAA@NSIDC, dataset G02135), National Snow and Ice Data Center.
État de départ vérifié
Computed base rate: 47% of past years (1988 onward, 38 years) saw the NSIDC monthly mean exceed the average of the first five days of the month by at least the margin implied by this threshold (threshold 7.05 million km2, first-five-day mean 5.76). One value per year: small sample. Data: NSIDC Sea Ice Index, Version 4 (NOAA@NSIDC, G02135).
Les arguments ci-dessous ont été produits par le modèle en anglais. Ils sont affichés tels quels plutôt que traduits automatiquement, pour que rien sur cette page ne soit un texte que Asturna n'a pas réellement écrit.
Ce qui fait monter
- The required increase from the first-five-day mean of 5.76 million km² to 7.05 million km² is +1.29 million km², which aligns almost exactly with the historical median gain of +1.29 million km² [tier 1].
- Through October 9, daily extent has steadily increased to 6.02 million km², bringing the 9-day average up to 5.87 million km² as freeze-up progresses [tier 1].
Ce qui fait descendre
- Long-term warming trends and elevated sea surface temperatures in recent decades have frequently delayed Arctic freeze-up and suppressed October extents below early-record averages [tier 1].
- Daily extent growth from October 6 (5.96 million km²) to October 9 (6.02 million km²) averaged only ~0.02 million km² per day, indicating a relatively modest rate of expansion in early October [tier 1].
Ce qui ferait le plus bouger ce chiffre
The rate of freeze-up acceleration across the second half of October, which depends heavily on atmospheric circulation patterns and polar air outbreaks.
Comment ce chiffre est fabriqué
| Échéance | 2026-11-10 |
| Taux de base | 47% |
| Meilleure preuve | niveau 1 · 1 article(s) utilisé(s) |
| Estimations | 42 · 44 · 58 (écart 16 pts) |
| Confiance | moyenne |
| Plafond de preuve | non déclenché |
| Révisée le | 2026-10-11 09:04 |
| Modèle | gemini-3.8-flash |
Sources consultées
Historique de la probabilité
2026-10-11 09:04 44% 6 article(s) au dossier · gemini-3.8-flash
- Ce qui fait monter. The required increase from the first-five-day mean of 5.76 million km² to 7.05 million km² is +1.29 million km², which aligns almost exactly with the historical median gain of +1.29 million km² [tier 1].
- Ce qui fait monter. Through October 9, daily extent has steadily increased to 6.02 million km², bringing the 9-day average up to 5.87 million km² as freeze-up progresses [tier 1].
- Ce qui fait descendre. Long-term warming trends and elevated sea surface temperatures in recent decades have frequently delayed Arctic freeze-up and suppressed October extents below early-record averages [tier 1].
- Ce qui fait descendre. Daily extent growth from October 6 (5.96 million km²) to October 9 (6.02 million km²) averaged only ~0.02 million km² per day, indicating a relatively modest rate of expansion in early October [tier 1].
- Ce qui ferait le plus bouger ce chiffre. The rate of freeze-up acceleration across the second half of October, which depends heavily on atmospheric circulation patterns and polar air outbreaks.
2026-10-09 13:52 49% 6 article(s) au dossier · gemini-3.7-flash
- Ce qui fait monter. Early daily data through October 7 shows steady refreeze, with extent rising from the 5-day average of 5.76 million km² to 6.01 million km² by October 7 [tier 1].
- Ce qui fait descendre. Arctic autumn freeze-up in recent decades has frequently experienced mid-to-late October slowdowns due to elevated sea surface temperatures and atmospheric warmth [tier 1].
- Ce qui ferait le plus bouger ce chiffre. The pace of Arctic refreeze during the remainder of October, particularly whether storm tracks or warm air intrusions stall ice advance in the peripheral seas.
2026-10-08 19:48 48% 0 article(s) au dossier · gemini-3.7-flash
- Ce qui fait monter. The required increase from the 5-day baseline (5.76 million km²) to reach 7.05 million km² is 1.29 million km², which aligns with the historical median monthly expansion (+1.29 million km²) [1].
- Ce qui fait monter. Daily extent reached 5.96 million km² on October 6, raising the 6-day average to 5.79 million km² and signaling steady early-month freeze-up momentum [1].
- Ce qui fait descendre. Long-term warming trends and elevated sea surface temperatures in recent decades have frequently delayed or dampened the rate of Arctic autumn refreezing [1].
- Ce qui fait descendre. Reaching a monthly average of 7.05 million km² requires maintaining a sustained rapid freeze-up pace without mid-month synoptic warm spells or storm disruptions [1].
- Ce qui ferait le plus bouger ce chiffre. The rate of Arctic sea ice refreeze over the remaining 25 days of October, which depends heavily on atmospheric circulation and oceanic heat loss.