{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"95b049d5b9612d3acf8c90cab60550a34cca6477aaa3dec7a515c5af80fdc333","created":"2026-10-03T07:18:03Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"5d2883d1228c22e072b6c530488f56874a62acbcee2cb73b996e83a39688cd57","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"earth.paleoclimate-puzzles.dansgaard-oeschger","kind":"phenomenon","literature_status":"open","n":"1","parents":[],"plain":"During the last ice age Greenland repeatedly warmed by 8 to 16 degrees within a few decades, then slowly cooled again, about 25 times. The trigger of these jumps, called Dansgaard-Oeschger events, is unknown.","posed_since":"","precise":"For the Greenland interstadial onsets of the last glacial period (about 115 to 12 kyr ago), determine whether the abrupt warmings are noise-induced transitions between AMOC states, self-sustained oscillations involving sea-ice and ocean stratification in the Nordic Seas, or forced by ice-sheet changes, and what sets their irregular spacing. An answer is a mechanism reproduced in a comprehensive model under glacial boundary conditions with the observed amplitude, rise time of decades, and Antarctic bipolar seesaw lag.","problem_ref":null,"references":"","settled_by":"Spontaneous Dansgaard-Oeschger-like cycles in comprehensive coupled models whose controlling variable is confirmed by high-resolution marine and ice-core proxies across events.","status_note":"","title":"What causes abrupt Dansgaard-Oeschger warmings during glacial periods?","topic_ref":"4f250e50d442c2085fd7091e2a80ea67262938b9c04552ef688788b2ebee9449"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"f8535a69d87a1525de1e9a2f1471806f4672fa5fd9322d0793c6e950923ddf11","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"8771ed0ad10602be733af36749695f993aaa2fdde7a376a5c1433901a589f924","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"QqK1EEwjws5uOvp8DfJ2AeqHPi37PyEVlm1jMu9xCT5Ib2CdNkUTTRGCzOWWLGBiL4vTNjUHdAV5vy4maPq9Bg"},"schema":"pubphys.envelope/1"},"record_hash":"f8535a69d87a1525de1e9a2f1471806f4672fa5fd9322d0793c6e950923ddf11","leaf_index":1347}