Publication Date:
2024-02-14
Description:
Sources of uncertainty (i.e., internal variability, model and scenario) in Atlantic Niño variability projections were quantified in 49 models participating in the Coupled Model Intercomparison Phases 5 (CMIP5) and 6 (CMIP6). By the end of the twenty‐first century, the ensemble mean change in Atlantic Niño variability is −0.07 ± 0.10˚C, with 80% of CMIP models projecting a decrease, and representing a 16% reduction relative to the 1981–2005 ensemble mean. Models' projections depict a large spread, with variability changes ranging from 0.23˚C to −0.50˚C. Internal variability is the main source of uncertainty until 2045 but model uncertainty dominates thereafter, eventually explaining up to 80% of the total uncertainty. The scenario uncertainty remains low (〈1%) throughout the twenty‐first century. The total uncertainty on Atlantic Niño variability projections is not improved when considering only CMIP models with a realistic zonal equatorial Atlantic sea surface temperature gradient.
Plain Language Summary
Sources of uncertainty (i.e., internal variability, model and scenario) in future projections of the Atlantic Niño variability were evaluated in global coupled models participating in the Coupled Model Intercomparison Phases 5 (CMIP5) and 6 (CMIP6). Relative to 1981–2005, models' projections depict a large spread, ranging from increasing Atlantic Niño variability by up to 0.23˚C to decreasing by up to −0.50˚C. By the end of the twenty‐first century, the ensemble mean Atlantic Niño variability change is −0.07 ± 0.10˚C with 80% of the global coupled models simulating a decrease. This change in the ensemble mean Atlantic Niño variability, relative to the period 1981–2005, represents a 16% reduction. During the first four decades of projection, the internal variability is the main contributor to the total uncertainty; thereafter model uncertainty dominates and explains up to 80% of the total uncertainty at the end of the twenty‐first century. The scenario uncertainty remains low (〈1%) throughout the twenty‐first century. The total uncertainty on Atlantic Niño variability projections is not improved when considering only CMIP models with a realistic zonal equatorial Atlantic sea surface temperature gradient.
Key Points
80% of the CMIP models simulate a decrease of the Atlantic Niño variability at the end of the 21st century
The model uncertainty explains about 80% of the total uncertainty on Atlantic Niño variability projections at the end of the 21st century
Global warming signal is not detectable throughout scenarios due to large internal variability and model uncertainties
Type:
Article
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PeerReviewed
,
info:eu-repo/semantics/article
Format:
text
Format:
text
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