Articles | Volume 10, issue 7
Geosci. Model Dev., 10, 2833–2848, 2017
https://doi.org/10.5194/gmd-10-2833-2017
Geosci. Model Dev., 10, 2833–2848, 2017
https://doi.org/10.5194/gmd-10-2833-2017

Model experiment description paper 21 Jul 2017

Model experiment description paper | 21 Jul 2017

“Climate response functions” for the Arctic Ocean: a proposed coordinated modelling experiment

John Marshall1, Jeffery Scott1, and Andrey Proshutinsky2 John Marshall et al.
  • 1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA
  • 2Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543-1050, USA

Abstract. A coordinated set of Arctic modelling experiments, which explore how the Arctic responds to changes in external forcing, is proposed. Our goal is to compute and compare climate response functions (CRFs) – the transient response of key observable indicators such as sea-ice extent, freshwater content of the Beaufort Gyre, etc. – to abrupt step changes in forcing fields across a number of Arctic models. Changes in wind, freshwater sources, and inflows to the Arctic basin are considered. Convolutions of known or postulated time series of these forcing fields with their respective CRFs then yield the (linear) response of these observables. This allows the project to inform, and interface directly with, Arctic observations and observers and the climate change community. Here we outline the rationale behind such experiments and illustrate our approach in the context of a coarse-resolution model of the Arctic based on the MITgcm. We conclude by summarizing the expected benefits of such an activity and encourage other modelling groups to compute CRFs with their own models so that we might begin to document their robustness to model formulation, resolution, and parameterization.

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Short summary
A coordinated set of Arctic modeling experiments is proposed which explores how the Arctic responds to abrupt changes in external forcing by computing climate response functions (CRFs). We illustrate the approach in the context of a coarse-resolution model of the Arctic and conclude by encouraging other modeling groups to compute CRFs with their own models so that we might begin to document how robust they are to model formulation, resolution, and parameterization.