High-resolution Greenland ice core data show abrupt climate change happens in few years.
The last two abrupt warmings at the onset of our present warm interglacial period, interrupted by the Younger Dryas cooling event, were investigated at high temporal resolution from the North Greenland Ice Core Project ice core. The deuterium excess, a proxy of Greenland precipitation moisture source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition, reflecting the wetting of Asian deserts. A northern shift of the Intertropical Convergence Zone could be the trigger of these abrupt shifts of Northern Hemisphere atmospheric circulation, resulting in changes of 2 to 4 kelvin in Greenland moisture source temperature from one year to the next.
Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen OE, Denmark. jps@gfy.ku.dk
Jørgen Peder
JP
Steffensen
Katrine K
KK
Andersen
Matthias
M
Bigler
Henrik B
HB
Clausen
Dorthe
D
Dahl-Jensen
Hubertus
H
Fischer
Kumiko
K
Goto-Azuma
Margareta
M
Hansson
Sigfús J
SJ
Johnsen
Jean
J
Jouzel
Valérie
V
Masson-Delmotte
Trevor
T
Popp
Sune O
SO
Rasmussen
Regine
R
Röthlisberger
Urs
U
Ruth
Bernhard
B
Stauffer
Marie-Louise
ML
Siggaard-Andersen
Arny E
AE
Sveinbjörnsdóttir
Anders
A
Svensson
James W C
JW
White