Projections of northern hemisphere extratropical climate underestimate internal variability and associated uncertainty

O'Reilly, C. H. ORCID: https://orcid.org/0000-0002-8630-1650, Befort, D. J., Weisheimer, A., Woollings, T., Ballinger, A. and Gabriele, H. (2021) Projections of northern hemisphere extratropical climate underestimate internal variability and associated uncertainty. Communications Earth & Environment, 2 (194). ISSN 2662-4435 doi: 10.1038/s43247-021-00268-7

Abstract/Summary

Internal climate variability will play a major role in determining change on regional scales under global warming. In the extratropics, large-scale atmospheric circulation is responsible for much of observed regional climate variability, from seasonal to multidecadal timescales. However, the extratropical circulation variability on multidecadal timescales is systematically weaker in coupled climate 1 models. Here we show that projections of future extratropical climate from coupled model simulations significantly underestimate the projected uncertainty range originating from large-scale atmospheric circulation variability. Using observational datasets and large ensembles of coupled climate models, we produce synthetic ensemble projections constrained to have variability consistent with the large-scale atmospheric circulation in observations. Compared to the raw model projections, the synthetic observationally-constrained projections exhibit an increased uncertainty in projected 21st century temperature and precipitation changes across much of the Northern extratropics. This increased uncertainty is also associated with an increase of the projected occurrence of future extreme seasons.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/99987
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Springer Nature
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