On the origin of multidecadal to centennial Greenland temperature anomalies over the past 800 yr

• DOI: 10.5194/cp-9-583-2013
• Publication Date: 2013-03-08T13:04:47Z
• Authors: T. Kobashi; D. T. Shindell; K. Kodera; J. E. Box; T. Nakaegawa; K. Kawamura
• Keywords: Greenland ice sheet; Ice core; Groenlandia; Temperature record; Proxy (statistics)

Abstract. The surface temperature of the Greenland ice sheet is among most important climate variables for assessing how change may impact human societies due to its association with sea level rise. However, causes multidecadal-to-centennial changes in temperatures are not well understood, largely owing short observational records. To examine these, we calculated anomalies (GTA[G-NH]) over past 800 yr by subtracting standardized northern hemispheric (NH) from temperature. This decomposes variation into background (NH); polar amplification; and regional variability (GTA[G-NH]). central amplification factor as expressed variance ratio Greenland/NH 2.6 161 yr, 3.3–4.2 yr. GTA[G-NH] explains 31–35% time scale We found that has been influenced solar-induced atmospheric circulation patterns such those produced North Atlantic Oscillation/Arctic Oscillation (NAO/AO). Climate modeling proxy records indicate anomaly also likely linked solar-paced meridional overturning (AMOC) associated northward oceanic heat transport.