Paper: Armstrong et al 2021

Title: Identifying the mechanisms of DO-scale oscillations in a GCM: The salt oscillator triggered by the Laurentide ice sheet

For a fuller description of the paper itself, go to the end of this web page.

Each simulation published in this paper corresponds to a unique 5 or 6 character code on the web pages.
The following table lists the name of the simulation as used in the paper, and the corresponding code name

The webpage gives you the ability to examine the published simulations, but you can also download the raw (netcdf) files to perform your own analysis. Detailed instructions on how to use the webpages and access the data can be found here: Using_BRIDGE_webpages.pdf

There are 10 simulations used in this study. See Table 2 for more information.

You can have make you own analysis and plots by going here

Simulation Name as in PaperSimulation name on web pages
30kyrBASEteipf
30kyrSTteipp
30kyrORBteipg
30kyrGHGteipb
30kyrBATHYteipo
28kyrFENteipu
28kyrELAUteipv
28kyrEWLAUteipw
28kyrLAUteipx
28kyr50teipy


This is a fuller description of paper

This paper investigates stochastic DO-scale variability in a GCM, driven by a North Atlantic salt oscillator triggered by the Laurentide ice sheet.

NameArmstrong et al. 2021
Brief DescriptionThis paper investigates stochastic DO-scale variability in a GCM, driven by a North Atlantic salt oscillator triggered by the Laurentide ice sheet.
Full Author ListArmstrong, E. and Izumi, K. and Valdes, P. J.
TitleIdentifying the mechanisms of DO-scale oscillations in a GCM: The salt oscillator triggered by the Laurentide ice sheet
Year2021
JournalClimate Dynamics
Volume2021
Issue
Pages
DOI
Contact's NameEdward Armstrong
Contact's emailedward.armstrong@bristol.ac.uk
AbstractThe driver mechanisms of Dansgaard-Oeschger (DO) events remain uncertain, in part because many climate models do not show similar oscillatory behaviour. Here we present results from glacial simulations of the HadCM3B coupled atmosphere-ocean-vegetation model that show stochastic, quasi-periodical DO-scale variability. This variability is driven by variations in the strength of the Atlantic Meridional Overturning Circulation in response to North Atlantic salinity fluctuations. The mechanism represents a salt oscillator driven by the salinity gradient between the subtropical gyre and the Northern North Atlantic. Utilising a full set of model salinity diagnostics, we identify a complex ocean-atmosphere-sea-ice feedback mechanism that maintains this oscillator, driven by the interplay between surface freshwater fluxes (tropical P-E balance and sea-ice), advection, and convection. The key trigger is the extent of the Laurentide ice sheet, which alters atmospheric and ocean circulation patterns, highlighting the sensitivity of the climate system to land-ice extent. This, in addition to the background climate state, pushes the climate beyond a tipping point and into an oscillatory mode on a timescale comparable to the DO events.