2024-03-28T16:48:30Z
https://kitami-it.repo.nii.ac.jp/oai
oai:kitami-it.repo.nii.ac.jp:02000423
2023-08-17T05:59:47Z
1:87
Shallow firn cores 1989–2019 in southwest Greenland's percolation zone reveal decreasing density and ice layer thickness after 2012
Åsa K. Rennermalm
Regine Hock
Federico Covi
Jing Xiao
Giovanni Corti
Jonathan Kingslake
Sasha Z. Leidman
Clément Miège
Michael Macferrin
Horst Machguth
Erich Osterberg
Takao Kameda
Joseph R. McConnell
Refreezing of meltwater in firn is a major component of Greenland ice-sheet's mass budget, but in situ observations are rare. Here, we compare the firn density and total ice layer thickness in the upper 15 m of 19 new and 27 previously published firn cores drilled at 15 locations in southwest Greenland (1850–2360 m a.s.l.) between 1989 and 2019. At all sites, ice layer thickness covaries with density over time and space. At the two sites with the earliest observations (1989 and 1998), bulk density increased by 15–18%, in the top 15 m over 28 and 21 years, respectively. However, following the extreme melt in 2012, elevation-detrended density using 30 cores from all sites decreased by 15 kg m−3 a−1 in the top 3.75 m between 2013 and 2019. In contrast, the lowest elevation site's density shows no trend. Thus, temporary build-up in firn pore space and meltwater infiltration capacity is possible despite the long-term increase in Greenland ice-sheet melting.
journal article
Cambridge University Press
2022-06
application/pdf
Journal of Glaciology
269
68
431
442
https://kitami-it.repo.nii.ac.jp/record/2000423/files/shallow-firn-cores-1989-2019-in-southwest-greenlands-percolation-zone-reveal-decreasing-density-and-ice-layer-thickness-after-2012(1).pdf
eng
https://doi.org/10.1017/jog.2021.102
© The Author(s), 2021
open access