NATURE CLIMATE CHANGE | www.nature.com/natureclimatechange 1 SUPPLEMENTARY INFORMATION DOI:10.1038/NCLIMATE2330 Supplementary Information, to “Recent Walker Circulation strengthening and Pacific cooling amplified by Atlantic warming”

• Main Authors: Shayne Mcgregor, Axel Timmermann, Malte F. Stuecker, Matthew H. Engl, Mark Merrifield, Jin Yoshimitsu Chikamoto
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Pacific; Sea ice
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.683.663; http://web.science.unsw.edu.au/%7Ematthew/mcgregor_et_al_2014_supmat.pdf

1. Partially coupled experiments Seven main CAM4 experiments make up the suite of partially coupled experiments for this study. In these experiments, we prescribe the 1992-2011 SST trend in some basins while allowing the ocean in the other basin/basins to integrate the atmospheric heat fluxes using a slab ocean thermodynamic mixed layer (ML) model. Summary details of these simulations can be found in Table S2. In the partially coupled experiments we always use the thermodynamic ML and thermodynamic sea-ice model polewards of 55o latitude. To avoid sharp SST gradients we utilize a buffer zone between 50o and 55o latitude, in which the prescribed SST boundary forcing is gradually merged with the SST obtained from the ML temperature tendency equation. Depending on the experiment, climatological SST boundary forcing is either prescribed or calculated using the ML model in the respective ocean basins (Table S2).