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Ice Core Records of West Greenland Melt and Climate Forcing
Author(s) -
Graeter K. A.,
Osterberg E. C.,
Ferris D. G.,
Hawley R. L.,
Marshall H. P.,
Lewis G.,
Meehan T.,
McCarthy F.,
Overly T.,
Birkel S. D.
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2017gl076641
Subject(s) - greenland ice sheet , meltwater , firn , ice core , climatology , geology , temperature record , future sea level , ice sheet , oceanography , climate change , forcing (mathematics) , sea surface temperature , glacier , cryosphere , sea ice , ice stream , geomorphology
Remote sensing observations and climate models indicate that the Greenland Ice Sheet (GrIS) has been losing mass since the late 1990s, mostly due to enhanced surface melting from rising summer temperatures. However, in situ observational records of GrIS melt rates over recent decades are rare. Here we develop a record of frozen meltwater in the west GrIS percolation zone preserved in seven firn cores. Quantifying ice layer distribution as a melt feature percentage (MFP), we find significant increases in MFP in the southernmost five cores over the past 50 years to unprecedented modern levels (since 1550 CE). Annual to decadal changes in summer temperatures and MFP are closely tied to changes in Greenland summer blocking activity and North Atlantic sea surface temperatures since 1870. However, summer warming of ~1.2°C since 1870–1900, in addition to warming attributable to recent sea surface temperature and blocking variability, is a critical driver of high modern MFP levels.