On the stochastic nature of the rapid climate shifts during the last ice age
The rapid climate shifts observed in the glacial climate are analysed. The transitions into the warm interstadial states, the onsets, are easy identifiable in the record. The distribution of waiting times between consecutive onsets is well fitted assuming the remaining residence time in each state t...
Published in: | Journal of Climate |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2009
|
Subjects: | |
Online Access: | https://orbit.dtu.dk/en/publications/0a9f78e1-aa7a-4683-bd16-4cf64d80dd1e https://doi.org/10.1175/2008JCLI2430.1 |
id |
ftdtupubl:oai:pure.atira.dk:publications/0a9f78e1-aa7a-4683-bd16-4cf64d80dd1e |
---|---|
record_format |
openpolar |
spelling |
ftdtupubl:oai:pure.atira.dk:publications/0a9f78e1-aa7a-4683-bd16-4cf64d80dd1e 2023-12-03T10:21:46+01:00 On the stochastic nature of the rapid climate shifts during the last ice age Ditlevsen, Peter Dalager Ditlevsen, Ove Dalager 2009 https://orbit.dtu.dk/en/publications/0a9f78e1-aa7a-4683-bd16-4cf64d80dd1e https://doi.org/10.1175/2008JCLI2430.1 eng eng info:eu-repo/semantics/restrictedAccess Ditlevsen , P D & Ditlevsen , O D 2009 , ' On the stochastic nature of the rapid climate shifts during the last ice age ' , Journal of Climate , vol. 22 , no. 2 , pp. 446-557 . https://doi.org/10.1175/2008JCLI2430.1 Dansgaard-Oeschger events last ice age temperature stochastics stadial and interstadial duration statistics NGRIP ice core data article 2009 ftdtupubl https://doi.org/10.1175/2008JCLI2430.1 2023-11-08T23:56:48Z The rapid climate shifts observed in the glacial climate are analysed. The transitions into the warm interstadial states, the onsets, are easy identifiable in the record. The distribution of waiting times between consecutive onsets is well fitted assuming the remaining residence time in each state to be independent on the past. That implies that it has a simple no memory exponential waiting time distribution, but with mean waiting time depending on the climate state. The mean waiting time from one onset to the next is around 2400 y. The most likely (maximum likelihood) distribution derived solely from the onset sequence is rather insensitive to the mean waiting time in the warm interstadials in the range 400-1200 y. When extending the analysis to include the transitions from the warm interstadials to the cold stadials observed with a larger uncertainty, the distributions in the two states are well fitted to exponential distributions with mean waiting times of around 800 y in the warm state and around 1600 y in the cold state. This observation is an important piece in the climate puzzle, since the fact that the climate is a no memory process indicates that the transitions are noise induced and the mean residence time in one state indicates how stable that climate state is to perturbations. The possibility of a hidden periodic driver is also investigated. The existence of such a driver cannot be ruled out by the relatively sparse data series (containing only 21 onsets). However, since the record is fitted just as well by the much simpler random model, this should be preferred from the point of view of simplicity. Article in Journal/Newspaper Dansgaard-Oeschger events ice core NGRIP Technical University of Denmark: DTU Orbit Journal of Climate 22 2 446 457 |
institution |
Open Polar |
collection |
Technical University of Denmark: DTU Orbit |
op_collection_id |
ftdtupubl |
language |
English |
topic |
Dansgaard-Oeschger events last ice age temperature stochastics stadial and interstadial duration statistics NGRIP ice core data |
spellingShingle |
Dansgaard-Oeschger events last ice age temperature stochastics stadial and interstadial duration statistics NGRIP ice core data Ditlevsen, Peter Dalager Ditlevsen, Ove Dalager On the stochastic nature of the rapid climate shifts during the last ice age |
topic_facet |
Dansgaard-Oeschger events last ice age temperature stochastics stadial and interstadial duration statistics NGRIP ice core data |
description |
The rapid climate shifts observed in the glacial climate are analysed. The transitions into the warm interstadial states, the onsets, are easy identifiable in the record. The distribution of waiting times between consecutive onsets is well fitted assuming the remaining residence time in each state to be independent on the past. That implies that it has a simple no memory exponential waiting time distribution, but with mean waiting time depending on the climate state. The mean waiting time from one onset to the next is around 2400 y. The most likely (maximum likelihood) distribution derived solely from the onset sequence is rather insensitive to the mean waiting time in the warm interstadials in the range 400-1200 y. When extending the analysis to include the transitions from the warm interstadials to the cold stadials observed with a larger uncertainty, the distributions in the two states are well fitted to exponential distributions with mean waiting times of around 800 y in the warm state and around 1600 y in the cold state. This observation is an important piece in the climate puzzle, since the fact that the climate is a no memory process indicates that the transitions are noise induced and the mean residence time in one state indicates how stable that climate state is to perturbations. The possibility of a hidden periodic driver is also investigated. The existence of such a driver cannot be ruled out by the relatively sparse data series (containing only 21 onsets). However, since the record is fitted just as well by the much simpler random model, this should be preferred from the point of view of simplicity. |
format |
Article in Journal/Newspaper |
author |
Ditlevsen, Peter Dalager Ditlevsen, Ove Dalager |
author_facet |
Ditlevsen, Peter Dalager Ditlevsen, Ove Dalager |
author_sort |
Ditlevsen, Peter Dalager |
title |
On the stochastic nature of the rapid climate shifts during the last ice age |
title_short |
On the stochastic nature of the rapid climate shifts during the last ice age |
title_full |
On the stochastic nature of the rapid climate shifts during the last ice age |
title_fullStr |
On the stochastic nature of the rapid climate shifts during the last ice age |
title_full_unstemmed |
On the stochastic nature of the rapid climate shifts during the last ice age |
title_sort |
on the stochastic nature of the rapid climate shifts during the last ice age |
publishDate |
2009 |
url |
https://orbit.dtu.dk/en/publications/0a9f78e1-aa7a-4683-bd16-4cf64d80dd1e https://doi.org/10.1175/2008JCLI2430.1 |
genre |
Dansgaard-Oeschger events ice core NGRIP |
genre_facet |
Dansgaard-Oeschger events ice core NGRIP |
op_source |
Ditlevsen , P D & Ditlevsen , O D 2009 , ' On the stochastic nature of the rapid climate shifts during the last ice age ' , Journal of Climate , vol. 22 , no. 2 , pp. 446-557 . https://doi.org/10.1175/2008JCLI2430.1 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1175/2008JCLI2430.1 |
container_title |
Journal of Climate |
container_volume |
22 |
container_issue |
2 |
container_start_page |
446 |
op_container_end_page |
457 |
_version_ |
1784269567487377408 |