Dansgaard-oeschger events

From Glossary of Meteorology

Dansgaard–Oeschger events

Warm–cold oscillations during the last glacial period recorded in the oxygen isotope record of the Greenland ice, and also found in biotic and isotopic indices from deep-sea sediments in the North Atlantic.

The warm phases of these events correspond to interstadials, persist for a few hundred to a few thousand years, and have very rapid onset and termination (as little as a few decades). The range of temperature change inferred for the regions where the snow was formed that ultimately produced the Greenland ice was several degrees Celsius. Named for the ice core paleoclimatologists Willi Dansgaard and Hans Oeschger, Dansgaard–Oeschger events between 80 000 and 20 000 years ago are grouped in 10 000- to 15 000-year periods of increasing cooling. The ending of each of these groups of events is marked by a major flux of icebergs into the North Atlantic, as evidenced by associated material found in ocean floor sediments. The temperature conditions in Greenland and the North Atlantic region then return to the higher level of the beginning of the group of Dansgaard–Oeschger events. Most of the Dansgaard–Oeschger events that lasted 2000 years or more coincide with warmer conditions in East Antarctica, also revealed by analysis of oxygen isotopes in ice.

Dansgaard, W., and H. Oeschger 1989. Past environmental long-term records from the Arctic. The Environmental Record in Glaciers and Ice Sheets. H. Oeschger and C. C. Langway Jr., Eds., Wiley, . 287–318.

Copyright 2022 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact permissions@ametsoc.org. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.