As scientists continue to warn about melting glaciers in the Antarctic, one key glacier in Greenland is growing again, NASA says.

The Jakobshavn Glacier, the fastest flowing and thinning glacier for the last 20 years, is thickening and flowing more slowly, researchers at NASA's Jet Propulsion Laboratory say in a study.

Although the glacier still continues to lose more ice to warmer ocean waters than it gains from accumulating snow, researchers note, Jakobshavn has shown signs it's advancing, not retreating.

"At first we didn't believe it," said Ala Khazendar, lead author of the study who works at NASA's Jet Propulsion Laboratory, in a statement. "We had pretty much assumed that Jakobshavn would just keep going on as it had over the last 20 years."

The study was published Monday in the peer-reviewed journal Nature Geoscience.

It found the growth is caused by a climate pattern which causes the northern Atlantic Ocean to flip between cooler and warmer waters every five to 20 years. Researchers discovered waters near the glacier were colder than they've been since the 1980s.

The study is based on data from NASA's Oceans Melting Greenland (OMG) mission, launched in 2016 to learn how ocean waters affect glaciers in Greenland.

Josh Willis, principal investigator of the OMG mission, said this cooling pattern is just a "temporary break" for the glacier, and will likely recede once the climate pattern warms waters again. "In the long run, the oceans are warming. And seeing the oceans have such a huge impact on the glaciers is bad news for Greenland's ice sheet."

Earlier this year, researchers warned Greenland was nearing a tipping point for melting ice. In January, a study published in the peer-reviewed journal Proceedings of the National Academy of Sciences found ice in Greenland was melting four times faster than it was 16 years ago.

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Follow Brett Molina on Twitter: @brettmolina23.