Links between the climate over the North Pacific and the North Atlantic oceans could lead to abrupt climate change.
Researchers have debated whether temperature and ocean fluctuations were in sync with each other during past climate changes. Summer Praetorius and Alan Mix of Oregon State University in Corvallis studied oxygen isotopes as a proxy for ocean temperature in three sediment cores from the Gulf of Alaska covering the past 18,000 years.
By comparing the Alaska samples to cores from northern Greenland, the scientists found that climate variables such as temperature changed synchronously between about 15,500 and 11,000 years ago — shortly before the end of the last ice age.
The authors suggest that this link could have shifted heat in both oceans towards the poles at the same time, triggering abrupt climate change. They add that similar connections may be important for future warming.