A new study reconstructs the path of frozen trees as they made their way across the Arctic Ocean over 500 years, giving scientists a unique look into changes in sea ice and currents over the last half millennium.
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By dating and tracing pieces of driftwood on beaches in Svalbard, Norway's archipelago in the Arctic Circle, scientists have determined where these fallen trees floated.
Retracing the driftwood's journey let the researchers reconstruct, for the first time, both the level of sea ice over time and the currents that propelled the driftwood laden ice.
Borne by rivers to the ocean, fallen trees from the north's expansive boreal forests can be frozen in sea ice and float far, but the new research shows fewer trees are making the long journey as the sea ice that carries them shrinks away.
The new study found a distinct drop in new driftwood arrivals over the last 30 years, reflecting the steep decline in sea ice coverage in a warming Arctic and provides a higher resolution picture of past Arctic Ocean conditions than other methods allow.
The study is published in the Journal of Geophysical Research: Oceans, which publishes research that advances our understanding of the ocean and its processes.
Sea ice is sensitive to climate change and is an important part of Arctic ecosystems, so understanding how ice, ocean temperatures and currents have varied together over time is necessary for predicting coming changes in the Arctic. But doing so can be elusive: Ice melts, after all. The oldest sea ice is only about four years old (and getting younger), so scientists need to turn to other records.
"This is the first time driftwood has been used to look at large scale changes in Arctic sea ice dynamics and circulation patterns," said geoscientist Georgia Hole at the University of Oxford, who led the study. ■
A hyperactive weather pattern will bring an expansive low pressure system across mainland U.S., resulting in widespread impactful weather to progress from west to east across the country through the next few days.