Paper: Millot-Weil et al 2025

Title: Asian summer monsoon orbital variability directly paced by CO2 and precession, not eccentricity

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

These are the key simulations showing four sets of 219 simulations covering the last 800 kyr forced by different combination of orbital-scale parameters (insolation, greenhouse gases and ice sheet)

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

Name of sequence of simulations as in PaperSimulation sequence name as in web pagesDetailed description of individual simulations within sequence
bbc_long_08 - Series of simulations combining insolation, ice sheet and greenhouse gases forcing, All_forcing.bbc_long_08Detailed List of Runs
bbc_long_09 - Series of simulations combining insolation and greenhouse gases changes but constant pre-industrial ice sheet, Orb_Ghg.bbc_long_09Detailed List of Runs
bbc_long_14 - Serie of simulations combining insolation and ice sheet changes but constant pre-industrial greenhouse gases, Orb_Ice.bbc_long_14Detailed List of Runs
bbc_long_10 - Series of simulations with insolations variations only, ice sheet and greenhouse gases constant at pre-industrial levels for every simulations, Orb_Only. Each simulation has been run for at least 500 years, the last 100 years are used to calculate the climate means.bbc_long_10Detailed List of Runs


This is a fuller description of paper

This paper presents individual impact of orbital-scale parameters on Asian summer monsoon variability through the last 800 kyr. Results come from four sets of equilibrium simulations run with the climate model HadCM3B and are forced by different combination of realistic orbital-scale parameters.

NameMillot-Weil et al 2025
Brief DescriptionThis paper presents individual impact of orbital-scale parameters on Asian summer monsoon variability through the last 800 kyr. Results come from four sets of equilibrium simulations run with the climate model HadCM3B and are forced by different combination of realistic orbital-scale parameters.
Full Author ListMillot-Weil, J., Valdes, P.J., Farnsworth, A.
TitleAsian summer monsoon orbital variability directly paced by CO2 and precession, not eccentricity
Year2025
JournalNature Communications
Volumexx
Issue3-4
Pagesxx
DOIxx
Contact's NameJeanne Millot-Weil
Contact's emailxk22684@bristol.ac.uk
Analysis Code Millot-Weil_et_al_2025_monsoon_codes.tar
AbstractGeological evidence has widely recorded changes in the Asian monsoon intensity paced at orbital time-scales, suggesting the implication of orbital-scale drivers: insolation, greenhouse gas and ice sheet changes. Modelling works have been useful to untangle the role of these drivers, but essentially focused on monsoon's intensity, at singular points in time, rather than on the large spectrum of variability showed by proxy records. Thus, our understanding of the controlling processes that lead to Asian monsoon variations at orbital time-scale is still relatively unknown. Here, we reach comparable time depth than geological records using a recently updated version of HadCM3 paleoclimate model. Four series of 219 equilibrium simulations have been performed, covering 800,000 years and differing by their orbital-scale forcings combination. We show direct influence of precession and greenhouse gas changes on Asian summer monsoon's pace while ice sheet and eccentricity rather impact its amplitude, at a large space scale.