Impact of meltwater on high-latitude early Last Interglacial climate

Recent data compilations of the early Last Interglacial period have indicated a bipolar temperature response at 130 ka, with colder-than-present temperatures in the North Atlantic and warmer-than-present temperatures in the Southern Ocean and over Antarctica. However, climate model simulations of th...

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Bibliographic Details
Published in:Climate of the Past
Main Authors: E. J. Stone, E. Capron, D. J. Lunt, A. J. Payne, J. S. Singarayer, P. J. Valdes, E. W. Wolff
Format: Article in Journal/Newspaper
Language:English
Published: Copernicus Publications 2016
Subjects:
geo
Online Access:https://doi.org/10.5194/cp-12-1919-2016
http://www.clim-past.net/12/1919/2016/cp-12-1919-2016.pdf
https://doaj.org/article/4cf4b7c2d1dc4f3ebe437bbfec3a1120
Description
Summary:Recent data compilations of the early Last Interglacial period have indicated a bipolar temperature response at 130 ka, with colder-than-present temperatures in the North Atlantic and warmer-than-present temperatures in the Southern Ocean and over Antarctica. However, climate model simulations of this period have been unable to reproduce this response, when only orbital and greenhouse gas forcings are considered in a climate model framework. Using a full-complexity general circulation model we perform climate model simulations representative of 130 ka conditions which include a magnitude of freshwater forcing derived from data at this time. We show that this meltwater from the remnant Northern Hemisphere ice sheets during the glacial–interglacial transition produces a modelled climate response similar to the observed colder-than-present temperatures in the North Atlantic at 130 ka and also results in warmer-than-present temperatures in the Southern Ocean via the bipolar seesaw mechanism. Further simulations in which the West Antarctic Ice Sheet is also removed lead to warming in East Antarctica and the Southern Ocean but do not appreciably improve the model–data comparison. This integrated model–data approach provides evidence that Northern Hemisphere freshwater forcing is an important player in the evolution of early Last Interglacial climate.