Greenland climate simulations show high Eemian surface melt which could explain reduced total air content in ice cores
<p>This study presents simulations of Greenland surface melt for the Eemian interglacial period (<span class="inline-formula">∼130 000</span> to 115 000 years ago) derived from regional climate simulations with a coupled surface energy balance model. Surface melt is of hi...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2021-01-01
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| Series: | Climate of the Past |
| Online Access: | https://cp.copernicus.org/articles/17/317/2021/cp-17-317-2021.pdf |
| Summary: | <p>This study presents simulations of Greenland surface melt for the
Eemian interglacial period (<span class="inline-formula">∼130 000</span> 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
<span class="inline-formula">∼30</span> melt days per year at Dye-3, corresponding to
more than 600 <span class="inline-formula">mm</span> water equivalent (w.e.) of annual melt. For higher
ice sheet locations, between 60 and 150 <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow class="unit"><mi mathvariant="normal">mm</mi><mspace width="0.125em" linebreak="nobreak"/><mi mathvariant="normal">w</mi><mo>.</mo><mi mathvariant="normal">e</mi><mo>.</mo><mspace linebreak="nobreak" width="0.125em"/><msup><mi mathvariant="normal">yr</mi><mrow><mo>-</mo><mn mathvariant="normal">1</mn></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="61pt" height="15pt" class="svg-formula" dspmath="mathimg" md5hash="60c3b99e0549315b6df532681dc3ea85"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="cp-17-317-2021-ie00001.svg" width="61pt" height="15pt" src="cp-17-317-2021-ie00001.png"/></svg:svg></span></span> on average
are simulated. At the summit of Greenland, this yields a refreezing
ratio of more than 25 <span class="inline-formula">%</span> 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.</p> |
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| ISSN: | 1814-9324 1814-9332 |