A region of cooling water in the North Atlantic Ocean near Iceland, nicknamed the Blue Blob, has likely slowed the melting of the island's glaciers for years, according to new research.
The new study uses climate models and field observations to show the cold water patch chilled the air over Iceland sufficiently to slow ice loss starting in 2011. The model predicts cooler water will persist in the North Atlantic, sparing Iceland's glaciers until about 2050.
Ocean and air temperatures are predicted to increase between 2050 and 2100, leading to accelerated melting.
While cooler water in the North Atlantic offers a temporary respite for Iceland's glaciers, the study's authors estimate that without steps to mitigate climate change, the glaciers could lose a third of their current ice volume by 2100 and be gone by 2300. If the country's 3,400 cubic kilometres of ice melt, sea level will rise by 9 millimetres.
"It's crucial to have an idea of the possible feedbacks in the Arctic because it's a region that is changing so fast. It's important to know what we can expect in a future warmer climate."
The origin and cause of the Blue Blob, which is located south of Iceland and Greenland, is still being investigated. The cold patch was most prominent during the winter of 2014-2015 when the sea surface temperature was about 1.4 degrees Celsius colder than normal.
"In the end, the message is still clear," said lead author Brice Noël, a climate modeler who specialises in polar ice sheets and glaciers at Utrecht University. "The Arctic is warming fast. If we wish to see glaciers in Iceland, then we have to curb the warming."
The paper is published in the AGU journal Geophysical Research Letters, which publishes high-impact, short-format reports with immediate implications spanning all Earth and space sciences. Its findings may help scientists to better understand the indirect effects of the ocean on glaciers.