Greenland climate simulations show high Eemian surface melt which could explain reduced total air content in ice cores
Greenland climate simulations show high Eemian surface melt which could explain reduced total air content in ice cores
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 mmw.e.yr-1 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.
- University of Copenhagen Denmark
- IT University of Copenhagen Denmark
- University of Bern Switzerland
- University of Oslo Norway
- UNIVERSITETET I BERGEN Norway
5216
Alley, R. B. and Anandakrishnan, S.: Variations in melt-Iayer frequency in the GISP2 ice core: implications for Holocene summer temperatures in central Greenland, available at: https://www. igsoc.org/annals/21/igs_annals_vol21_year1995_pg64-70.pdf (last access: 13 January 2021), 1995.
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Capron, E., Govin, A., Stone, E. J., Masson-Delmotte, V., Mulitza, S., Otto-Bliesner, B., Rasmussen, T. L., Sime, L. C., Waelbroeck, C., and Wolff, E. W.: Temporal and spatial structure of multi-millennial temperature changes at high latitudes during the Last Interglacial, Quaternary Sci. Rev., 103, 116-133, https://doi.org/10.1016/j.quascirev.2014.08.018, 2014. [OpenAIRE]
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Eicher, O., Baumgartner, M., Schilt, A., Schmitt, J., Schwander, J., Stocker, T. F., and Fischer, H.: Climatic and insolation control on the high-resolution total air content in the NGRIP ice core, Clim. Past, 12, 1979-1993, https://doi.org/10.5194/cp12-1979-2016, 2016 (available at: https://www.ncdc.noaa.gov/ paleo-search/study/20569, last access: 27 November 2020). [OpenAIRE]
Faber, A.: Isotopes in Greenland precipitation: Isotope-enabled AGCM modelling and a new Greenland database of observations and ice core measurements, PhD thesis, Centre for Ice and Climate, University of Copenhagen, 2016.
Fettweis, X.: Reconstruction of the 19792006 Greenland ice sheet surface mass balance using the regional climate model MAR, The Cryosphere, 1, 21-40, https://doi.org/10.5194/tc-1-21-2007, 2007.
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Popularity provided by BIP!- University of Copenhagen Denmark
- IT University of Copenhagen Denmark
- University of Bern Switzerland
- University of Oslo Norway
- UNIVERSITETET I BERGEN Norway
- University of Copenhagen Denmark
- University of Bern, Climate and Environmental Physics Switzerland
- Københavns Universitet Denmark
- University of Vienna Austria
- University of Copenhagen Denmark
- KOBENHAVNS UNIVERSITET Denmark
- University of Oslo Norway
- University of Copenhagen Denmark
- University of Copenhagen Denmark
- KOBENHAVNS UNIVERSITET Denmark
- University of Copenhagen Denmark
- Centre for Ice and Climate Niels Bohr Institute University of Copenhagen Denmark
- University of Copenhagen Denmark
- University of Copenhagen Denmark
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 mmw.e.yr-1 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.