Dansgaard–Oeschger event

A rapid climate fluctuation during the last glacial period, marked by abrupt warming in Greenland followed by slower cooling. Its clearest records come from Greenland ice cores.

Atlantic meridional overturning circulation: A system of Atlantic Ocean currents that transports heat northward in surface waters and returns cold water at depth. Changes in its strength are a leading explanation for the North Atlantic temperature shifts.
Greenland ice core: A cylindrical sample of layered ice drilled from a Greenland ice sheet, preserving records of past climate and atmosphere. Its annually layered snow and chemical signals provide the primary event records.
Willi Dansgaard: A Danish geophysicist who pioneered the use of oxygen isotopes in ice cores to reconstruct past climate. His analysis of Greenland ice revealed abrupt glacial climate changes.
Dansgaard–Oeschger event 1: The final major abrupt warming in Greenland near the end of the last glacial period, around the start of the Bølling–Allerød. It is the best-known event because it led into the last glacial termination.
North Atlantic sea ice: Floating sea ice covering parts of the North Atlantic Ocean, varying with climate and season. Changes in its extent can amplify regional cooling and warming during these events.
Oxygen isotope ratio: The relative abundance of oxygen-18 and oxygen-16 isotopes in a sample, used to infer past temperatures and water cycles. Abrupt shifts in Greenland ice isotope ratios mark rapid temperature changes.
Hans Oeschger: A Swiss physicist who developed methods for measuring carbon dioxide in air trapped in ice cores. His work on ice-core records helped establish the abrupt events named with Dansgaard.
Bølling–Allerød: A warm interval near the end of the last glacial period, beginning about 14,700 years ago and preceding the Younger Dryas. Its onset is commonly treated as the final major Dansgaard–Oeschger warming.
Heinrich event: A cold interval during which large numbers of icebergs entered the North Atlantic from collapsing ice sheets. Both are abrupt glacial climate shifts, but Heinrich events are identified by distinct iceberg-debris layers.
Ice core dating: Methods for assigning ages to ice layers using annual counts, volcanic markers, and other chronological evidence. Dating allows abrupt changes in separate cores to be matched across time.

Linked from 16 pages