Correcting for artificial heat in coupled sea ice perturbation experiments

• Main Authors: Fraser-Leach, Luke, Audette, Alexandre, Kushner, Paul J.
• Format: Other/Unknown Material
• Language: unknown
• Published: Authorea, Inc. 2023
• Subjects: Arctic; albedo; Sea ice
• Online Access: http://dx.doi.org/10.22541/essoar.169272219.90860409/v1

A common approach to assessing how polar amplification affects lower latitude climate is to perform coupled ocean-atmosphere experiments in which sea ice is perturbed to a future state. A recent critique by M. England and others uses a simple 1-dimensional energy balance model (EBM) to show that sea ice perturbation experiments add artificial heat to the climate system. We explore this effect in a broader range of models and suggest a technique to correct for the artificial heat post-hoc. Our technique successfully corrects for artificial heat in the EBM and a possible generalization of this approach is developed to correct for artificial heat in an albedo modification experiment in a comprehensive earth system model. However, this technique can not be directly generalized to sea ice perturbation methodologies that employ a “ghost flux” seen only by the sea ice model. Applying the correction to the comprehensive albedo modification experiment, we find stronger artificial warming than in the EBM. Failing to account for the artificial heat also leads to overestimation of the climate response to sea ice loss, and can suggest false or artificially strong “tugs-of-war” between 19 low latitude warming and sea ice loss over some fields, for example Arctic surface temperature and 20 zonal wind.