Old Rocks
Diamond Member
This century is going to see some real interesting changes.
Nonlinear rise in Greenland runoff in response to post-industrial Arctic warming | Nature
LETTER
https://doi.org/10.1038/s41586-018-0752-4
Nonlinear rise in Greenland runoff in response to
post-industrial Arctic warming
Luke D. Trusel
1,2
*, Sarah B. Das
2
, Matthew B. Osman
3
, Matthew J. Evans
4
, Ben E. Smith
5
, Xavier Fettweis
6
, Joseph R. McConnell
7
,
Brice P. Y. Noël
8
& Michiel R. van den Broeke
8
The Greenland ice sheet (GrIS) is a growing contributor to global
sea-level rise
1
, with recent ice mass loss dominated by surface
meltwater runoff
2,3
. Satellite observations reveal positive trends in
GrIS surface melt extent
4
, but melt variability, intensity and runoff
remain uncertain before the satellite era. Here we present the first
continuous, multi-century and observationally constrained record of
GrIS surface melt intensity and runoff, revealing that the magnitude
of recent GrIS melting is exceptional over at least the last 350 years.
We develop this record through stratigraphic analysis of central
west Greenland ice cores, and demonstrate that measurements of
refrozen melt layers in percolation zone ice cores can be used to
quantifiably, and reproducibly, reconstruct past melt rates. We show
significant (P < 0.01) and spatially extensive correlations between
these ice-core-derived melt records and modelled melt rates
5,6
and
satellite-derived melt duration
4
across Greenland more broadly,
enabling the reconstruction of past ice-sheet-scale surface melt
intensity and runoff. We find that the initiation of increases in GrIS
melting closely follow the onset of industrial-era Arctic warming
in the mid-1800s, but that the magnitude of GrIS melting has only
recently emerged beyond the range of natural variability. Owing to
a nonlinear response of surface melting to increasing summer air
temperatures, continued atmospheric warming will lead to rapid
increases in GrIS runoff and sea-level contributions.
Nonlinear rise in Greenland runoff in response to post-industrial Arctic warming | Nature
LETTER
https://doi.org/10.1038/s41586-018-0752-4
Nonlinear rise in Greenland runoff in response to
post-industrial Arctic warming
Luke D. Trusel
1,2
*, Sarah B. Das
2
, Matthew B. Osman
3
, Matthew J. Evans
4
, Ben E. Smith
5
, Xavier Fettweis
6
, Joseph R. McConnell
7
,
Brice P. Y. Noël
8
& Michiel R. van den Broeke
8
The Greenland ice sheet (GrIS) is a growing contributor to global
sea-level rise
1
, with recent ice mass loss dominated by surface
meltwater runoff
2,3
. Satellite observations reveal positive trends in
GrIS surface melt extent
4
, but melt variability, intensity and runoff
remain uncertain before the satellite era. Here we present the first
continuous, multi-century and observationally constrained record of
GrIS surface melt intensity and runoff, revealing that the magnitude
of recent GrIS melting is exceptional over at least the last 350 years.
We develop this record through stratigraphic analysis of central
west Greenland ice cores, and demonstrate that measurements of
refrozen melt layers in percolation zone ice cores can be used to
quantifiably, and reproducibly, reconstruct past melt rates. We show
significant (P < 0.01) and spatially extensive correlations between
these ice-core-derived melt records and modelled melt rates
5,6
and
satellite-derived melt duration
4
across Greenland more broadly,
enabling the reconstruction of past ice-sheet-scale surface melt
intensity and runoff. We find that the initiation of increases in GrIS
melting closely follow the onset of industrial-era Arctic warming
in the mid-1800s, but that the magnitude of GrIS melting has only
recently emerged beyond the range of natural variability. Owing to
a nonlinear response of surface melting to increasing summer air
temperatures, continued atmospheric warming will lead to rapid
increases in GrIS runoff and sea-level contributions.
