Arctic cut-off high drives the poleward shift of a new Greenland melting record.
Large-scale atmospheric circulation controls the mass and energy balance of the Greenland ice sheet through its impact on radiative budget, runoff and accumulation. Here, using reanalysis data and the outputs of a regional climate model, we show that the persistence of an exceptional atmospheric ridge, centred over the Arctic Ocean, was responsible for a poleward shift of runoff, albedo and surface temperature records over the Greenland during the summer of 2015. New records of monthly mean zonal winds at 500 hPa and of the maximum latitude of ridge peaks of the 5,700±50 m isohypse over the Arctic were associated with the formation and persistency of a cutoff high. The unprecedented (1948-2015) and sustained atmospheric conditions promoted enhanced runoff, increased the surface temperatures and decreased the albedo in northern Greenland, while inhibiting melting in the south, where new melting records were set over the past decade.
Lamont-Doherty Earth Observatory, Columbia University, New York, New York 10964, USA.|NASA Goddard Institute of Space Studies, New York, New York 10025, USA.
M
M
Tedesco
University of Georgia, Athens, Georgia 30602-2502, USA.
T
T
Mote
University of Liege, Liege 4000, Belgium.
X
X
Fettweis
University of Sheffield, Sheffield S10 2TN, UK.
E
E
Hanna
The City College of New York, New York, New York 10031, USA.
J
J
Jeyaratnam
The City College of New York, New York, New York 10031, USA.
J F
JF
Booth
Lamont-Doherty Earth Observatory, Columbia University, New York, New York 10964, USA.|The City College of New York, New York, New York 10031, USA.|The Graduate Center of the City University of New York, New York, New York 10016, USA.
R
R
Datta
University of Leeds, Leeds LS2 9JT, UK.
K
K
Briggs