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Decadal-scale progression of the onset of Dansgaard-Oeschger warming events

Erhardt, Tobias ; Capron, Emilie ; Olander Rasmussen, Sune ; Schüpbach, Simon ; Bigler, Matthias ; Adolphi, Florian LU and Fischer, Hubertus (2019) In Climate of the Past 15(2). p.811-825
Abstract

During the last glacial period, proxy records throughout the Northern Hemisphere document a succession of rapid millennial-scale warming events, called Dansgaard-Oeschger (DO) events. A range of different mechanisms has been proposed that can produce similar warming in model experiments; however, the progression and ultimate trigger of the events are still unknown. Because of their fast nature, the progression is challenging to reconstruct from paleoclimate data due to the limited temporal resolution achievable in many archives and cross-dating uncertainties between records. Here, we use new high-resolution multi-proxy records of sea-salt (derived from sea spray and sea ice over the North Atlantic) and terrestrial (derived from the... (More)

During the last glacial period, proxy records throughout the Northern Hemisphere document a succession of rapid millennial-scale warming events, called Dansgaard-Oeschger (DO) events. A range of different mechanisms has been proposed that can produce similar warming in model experiments; however, the progression and ultimate trigger of the events are still unknown. Because of their fast nature, the progression is challenging to reconstruct from paleoclimate data due to the limited temporal resolution achievable in many archives and cross-dating uncertainties between records. Here, we use new high-resolution multi-proxy records of sea-salt (derived from sea spray and sea ice over the North Atlantic) and terrestrial (derived from the central Asian deserts) aerosol concentrations over the period 10-60 ka from the North Greenland Ice Core Project (NGRIP) and North Greenland Eemian Ice Drilling (NEEM) ice cores in conjunction with local precipitation and temperature proxies from the NGRIP ice core to investigate the progression of environmental changes at the onset of the warming events at annual to multi-annual resolution. Our results show on average a small lead of the changes in both local precipitation and terrestrial dust aerosol concentrations over the change in sea-salt aerosol concentrations and local temperature of approximately one decade. This suggests that, connected to the reinvigoration of the Atlantic meridional overturning circulation and the warming in the North Atlantic, both synoptic and hemispheric atmospheric circulation changes at the onset of the DO warming, affecting both the moisture transport to Greenland and the Asian monsoon systems. Taken at face value, this suggests that a collapse of the sea-ice cover may not have been the initial trigger for the DO warming.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Climate of the Past
volume
15
issue
2
pages
15 pages
publisher
Copernicus Gesellschaft mbH
external identifiers
  • scopus:85064912719
ISSN
1814-9324
DOI
10.5194/cp-15-811-2019
language
English
LU publication?
yes
id
ec63e662-afdd-42c1-8287-0ffec7bd448d
date added to LUP
2019-05-15 14:44:17
date last changed
2020-10-07 06:28:30
@article{ec63e662-afdd-42c1-8287-0ffec7bd448d,
  abstract     = {<p>During the last glacial period, proxy records throughout the Northern Hemisphere document a succession of rapid millennial-scale warming events, called Dansgaard-Oeschger (DO) events. A range of different mechanisms has been proposed that can produce similar warming in model experiments; however, the progression and ultimate trigger of the events are still unknown. Because of their fast nature, the progression is challenging to reconstruct from paleoclimate data due to the limited temporal resolution achievable in many archives and cross-dating uncertainties between records. Here, we use new high-resolution multi-proxy records of sea-salt (derived from sea spray and sea ice over the North Atlantic) and terrestrial (derived from the central Asian deserts) aerosol concentrations over the period 10-60&amp;thinsp;ka from the North Greenland Ice Core Project (NGRIP) and North Greenland Eemian Ice Drilling (NEEM) ice cores in conjunction with local precipitation and temperature proxies from the NGRIP ice core to investigate the progression of environmental changes at the onset of the warming events at annual to multi-annual resolution. Our results show on average a small lead of the changes in both local precipitation and terrestrial dust aerosol concentrations over the change in sea-salt aerosol concentrations and local temperature of approximately one decade. This suggests that, connected to the reinvigoration of the Atlantic meridional overturning circulation and the warming in the North Atlantic, both synoptic and hemispheric atmospheric circulation changes at the onset of the DO warming, affecting both the moisture transport to Greenland and the Asian monsoon systems. Taken at face value, this suggests that a collapse of the sea-ice cover may not have been the initial trigger for the DO warming.</p>},
  author       = {Erhardt, Tobias and Capron, Emilie and Olander Rasmussen, Sune and Schüpbach, Simon and Bigler, Matthias and Adolphi, Florian and Fischer, Hubertus},
  issn         = {1814-9324},
  language     = {eng},
  number       = {2},
  pages        = {811--825},
  publisher    = {Copernicus Gesellschaft mbH},
  series       = {Climate of the Past},
  title        = {Decadal-scale progression of the onset of Dansgaard-Oeschger warming events},
  url          = {http://dx.doi.org/10.5194/cp-15-811-2019},
  doi          = {10.5194/cp-15-811-2019},
  volume       = {15},
  year         = {2019},
}