By Chris Spears

DENVER (CBS4) – Climate scientists at the National Center for Atmospheric Research in Boulder say they can now predict if Arctic sea ice will grow, shrink or hold its own over the next several years.

The team has found a direct relationship between changes in the ice and changes in the circulation of the North Atlantic ocean.

“We know that over the long term, winter sea ice will continue to retreat,” said NCAR scientist Stephen Yeager. “But we are predicting that the rate will taper off for several years in the future before resuming.”

Yeager and his team stress that this prediction is not a recovery from the effects of human-caused global warming.

Researchers use snow machines to travel across sea ice on the Chukchi Sea near Barrow, Alaska. This image was taken during the OASIS (Ocean_Atmosphere_Sea Ice_Snowpack) field project. Part of International Polar Year, OASIS tackled a number of standing questions in polar chemistry, with the emphasis on the life cycle of pollutants that drift into the Arctic. (credit: NCAR)

Researchers use snow machines to travel across sea ice on the Chukchi Sea near Barrow, Alaska. This image was taken during the OASIS (Ocean_Atmosphere_Sea Ice_Snowpack) field project. Part of International Polar Year, OASIS tackled a number of standing questions in polar chemistry, with the emphasis on the life cycle of pollutants that drift into the Arctic. (credit: NCAR)

Scientists say the key to predicting sea ice is to accurately represent the Atlantic Meridional Overturning Circulation (AMOC) in their forecast models.

AMOC is a circulation that carries warm ocean waters from the tropics toward the North Atlantic. The waters then cool as they sink toward the bottom of the ocean and flow back south.

When this ocean circulation is strong, large amounts of warm water are carried north toward the North Atlantic and Arctic oceans, accelerating the loss of sea ice.

But when the AMOC is weak the warm waters stay further south and its effects on sea ice are reversed.

(credit: NCAR)

(credit: NCAR)

The cycle of AMOC can vary in intensity and it occurs over multiple years to even decades. Because it takes so long for this variation to evolve it can give climate scientists at NCAR the ability to somewhat predict what lies ahead.

In a recent study scientists at NCAR say AMOC appears to be weakening and that will potentially allow the extent of winter sea ice to expand in the coming years, temporarily masking the impacts of climate change.

The downward trend in the loss of sea ice should be noticed the most on the Atlantic side of the arctic where AMOC has the most influence.

Arctic sea ice typically grows to a maximum in late February when the planet is coldest after a long and dark winter.

Sea ice on the Chukchi Sea near Barrow, Alaska. This image was taken during the OASIS (Ocean_Atmosphere_Sea Ice_Snowpack) field project. Part of International Polar Year, OASIS tackled a number of standing questions in polar chemistry, with the emphasis on the life cycle of pollutants that drift into the Arctic. (credit: NCAR)

Sea ice on the Chukchi Sea near Barrow, Alaska. This image was taken during the OASIS (Ocean_Atmosphere_Sea Ice_Snowpack) field project. Part of International Polar Year, OASIS tackled a number of standing questions in polar chemistry, with the emphasis on the life cycle of pollutants that drift into the Arctic. (credit: NCAR)

Scientists involved in this study do caution that their predictions are based off relatively short climate records. Satellite data of sea ice dates back to 1979 and AMOC has only been directly measured since 2004.

“The sea ice record is so short that it’s difficult to use statistics alone to build confidence in our predictions,” Yeager said. “Much of our confidence stems from the fact that our model does well at predicting slow changes in ocean heat transport and sea surface temperature in the subpolar North Atlantic, and these appear to impact the rate of sea ice loss. So, we think that we understand the mechanisms underpinning our sea ice prediction skill.”

Meteorologist Chris Spears writes about stories related to weather and climate in Colorado. Check out his bio, connect with him on Facebook or follow him on Twitter @ChrisCBS4.