Sea ice in the Arctic Ocean is in a downward spiral, with summer minimum extents about 40 percent smaller than in the 1980s. But predicting how the sea ice is going to behave in a particular year is tricky: There are still many unknowns about the conditions of the sea ice cover, to say nothing of the difficulties of forecasting weather and ocean behavior over seasonal timescales.
Sea ice in the Arctic Ocean is in a downward spiral, with summer minimum extents about 40 percent smaller than in the 1980s. But predicting how the sea ice is going to behave in a particular year is tricky: There are still many unknowns about the conditions of the sea ice cover, to say nothing of the difficulties of forecasting weather and ocean behavior over seasonal timescales.
NASA researchers are working to improve their forecasts of the size of the Arctic sea ice cover at the end of the summer melt season — but the goal is not just to have a better prediction of sea ice coverage. The challenge of making summer sea ice forecasts allows scientists to test their understanding of the processes that control seasonal sea ice growth and retreat, and to fine-tune computer models that represent connections among the ice, atmosphere and ocean.
A grassroots initiative launched in 2008 compares the efforts of different research teams each year to predict end-of-summer Arctic sea ice. This year, three NASA teams are among over three dozen groups that submitted at least one prediction. The participating groups in the Sea Ice Prediction Network (SIPN) use different methods, ranging from statistical analysis to dynamic models, gut feelings and combinations of techniques. Teams can submit forecasts in June, July and August based on the current sea ice conditions at those times. Each fall, the project releases an analysis of the year’s submissions, reviewing lessons learned and providing guidance to future research efforts.
The comparison of different methods allows scientists to go beyond simply collecting observations of sea ice characteristics to test hypotheses about the drivers of sea behavior in a particular year. As an example, such methods will allow researchers to more closely examine the impact of summer ice thickness or the presence of melt water ponds at the beginning of the melt season. It will also let them determine whether a singular characteristic of the ice is more useful than analyzing a combination of factors.
Read more at NASA/Goddard Space Flight Center
Image: Many melt ponds on sea ice north of Greenland, as seen during an Operation IceBridge flight on July 24, 2017. (Credit: NASA/Nathan Kurtz)
