Greenland climate simulations show high Eemian surface melt which could explain reduced total air content in ice cores

Author(s)
Andreas Plach, Bo M. Vinther, Kerim H. Nisancioglu, Sindhu Vudayagiri, Thomas Blunier
Abstract

This study presents simulations of Greenland surface melt for the Eemian interglacial period (∼130 000 to 115 000 years ago) derived from regional climate simulations with a coupled surface energy balance model. Surface melt is of high relevance due to its potential effect on ice core observations, e.g., lowering the preserved total air content (TAC) used to infer past surface elevation. An investigation of surface melt is particularly interesting for warm periods with high surface melt, such as the Eemian interglacial period. Furthermore, Eemian ice is the deepest and most compressed ice preserved on Greenland, resulting in our inability to identify melt layers visually. Therefore, simulating Eemian melt rates and associated melt layers is beneficial to improve the reconstruction of past surface elevation. Estimated TAC, based on simulated melt during the Eemian, could explain the lower TAC observations. The simulations show Eemian surface melt at all deep Greenland ice core locations and an average of up to ∼30 melt days per year at Dye-3, corresponding to more than 600 mm water equivalent (w.e.) of annual melt. For higher ice sheet locations, between 60 and 150 mm w.e. per year on average are simulated. At the summit of Greenland, this yields a refreezing ratio of more than 25 % of the annual accumulation. As a consequence, high melt rates during warm periods should be considered when interpreting Greenland TAC fluctuations as surface elevation changes. In addition to estimating the influence of melt on past TAC in ice cores, the simulated surface melt could potentially be used to identify coring locations where Greenland ice is best preserved.

Organisation(s)
Department of Meteorology and Geophysics
External organisation(s)
University of Copenhagen, University of Bergen (UiB)
Journal
Climate of the Past
Volume
17
Pages
317–330
No. of pages
14
ISSN
1814-9324
DOI
https://doi.org/10.5194/cp-17-317-2021
Publication date
2020
Peer reviewed
Yes
Austrian Fields of Science 2012
105206 Meteorology
Keywords
ASJC Scopus subject areas
Global and Planetary Change, Palaeontology, Stratigraphy
Sustainable Development Goals
SDG 13 - Climate Action
Portal url
https://ucrisportal.univie.ac.at/en/publications/cc0861bf-5813-4ef7-831a-1ae04f39a7a6