TY  - JOUR
AU  - Mindlin, Julia
AU  - Shepherd, Theodore G.
AU  - Osman, Marisol
AU  - Vera, Carolina S.
AU  - Kretschmer, Marlene
TI  - Explaining and predicting the Southern Hemisphere eddy-driven jet
JO  - Proceedings of the National Academy of Sciences of the United States of America
VL  - 122
IS  - 29
SN  - 0027-8424
CY  - Washington, DC
PB  - National Acad. of Sciences
M1  - FZJ-2025-04511
SP  - e2500697122
PY  - 2025
AB  - The summertime eddy-driven jet (EDJ) in the Southern Hemisphere is a critical mediatorbetween regional climate and large-scale phenomena, guiding synoptic systems thatshape weather patterns. Uncertainties in global climate models (GCMs)-particularlyin projecting changes in remote drivers like tropical warming, stratospheric polarvortex strengthening, and asymmetric tropical Pacific warming-hinder predictions ofEDJ trends and associated regional outcomes. In this study, we develop a causalframework that combines observations, reanalysis datasets, and storylines estimatedfrom the Coupled Model Intercomparison Project (CMIP) projections to attributepast EDJ changes and predict plausible future trajectories. Our findings indicate thattropical warming has evolved along the low end of plausible CMIP trajectories, whilethe stratospheric polar vortex shows robust strengthening, both strongly influencingobserved EDJ trends. Our results suggest that 50% of the observed EDJ latitudeshift can be directly attributed to global warming (GW), and the remaining 50% toremote drivers whose attribution toGWremains uncertain. Importantly,GCMsappearto accurately estimate the observed latitudinal shifts but underestimate the observedstrengthening of the EDJ, while the proposed storylines are able to capture the observedtrend. By integrating causal inference with climate storylines, our approach narrowsthe divide between attribution and prediction, offering a physically grounded methodto estimate plausible pathways of future climate change.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1073/pnas.2500697122
UR  - https://juser.fz-juelich.de/record/1048120
ER  -