Decadal predictions with the HiGEM high resolution global coupled climate model: description and basic evaluation

Shaffrey, L. C. ORCID: https://orcid.org/0000-0003-2696-752X, Hodson, D. ORCID: https://orcid.org/0000-0001-7159-6700, Robson, J. ORCID: https://orcid.org/0000-0002-3467-018X, Stevens, D. P., Hawkins, E. ORCID: https://orcid.org/0000-0001-9477-3677, Polo, I., Stevens, I., Sutton, R. T. ORCID: https://orcid.org/0000-0001-8345-8583, Lister, G., Iwi, A., Smith, D. and Stephens, A. (2017) Decadal predictions with the HiGEM high resolution global coupled climate model: description and basic evaluation. Climate Dynamics, 48 (1). pp. 297-311. ISSN 1432-0894 doi: 10.1007/s00382-016-3075-x

Abstract/Summary

This paper describes the development and basic evaluation of decadal predictions produced using the HiGEM coupled climate model. HiGEM is a higher resolution version of the HadGEM1 Met Office Unified Model. The horizontal resolution in HiGEM has been increased to 1.25◦ × 0.83◦ in longitude and latitude for the atmosphere, and 1/3◦ × 1/3◦ globally for the ocean. The HiGEM decadal predictions are initialised using an anomaly assimilation scheme that relaxes anomalies of ocean temperature and salinity to observed anomalies. 10 year hindcasts are produced for 10 start dates (1960, 1965,..., 2000, 2005). To determine the relative contributions to prediction skill from initial conditions and external forcing, the HiGEM decadal predictions are compared to uninitialised HiGEM transient experiments. The HiGEM decadal predictions have substantial skill for predictions of annual mean surface air temperature and 100 m upper ocean temperature. For lead times up to 10 years, anomaly correlations (ACC) over large areas of the North Atlantic Ocean, the Western Pacific Ocean and the Indian Ocean exceed values of 0.6. Initialisation of the HiGEM decadal predictions significantly increases skill over regions of the Atlantic Ocean,the Maritime Continent and regions of the subtropical North and South Pacific Ocean. In particular, HiGEM produces skillful predictions of the North Atlantic subpolar gyre for up to 4 years lead time (with ACC > 0.7), which are significantly larger than the uninitialised HiGEM transient experiments.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/63682
Identification Number/DOI	10.1007/s00382-016-3075-x
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Environmental Systems Science Centre Science > School of Mathematical, Physical and Computational Sciences > NCAS Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Uncontrolled Keywords	decadal_prediction, higem
Publisher	Springer
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