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Title: 1,000 Predictions: What's New and What's Old in a Retrospective Analysis of the Sea Ice Outlook, 2008-2020
Each Arctic summer since 2008, the Sea Ice Outlook (SIO) has invited researchers and the engaged public to contribute predictions regarding the September extent of Arctic sea ice. Then, each September, we see the accuracy or inaccuracy of those predictions. More than 1,000 individual predictions, based on many different methods, were contributed from 2008 to 2020. Earlier papers analyzed the ensemble skill of the first few hundred SIO contributions through 2013 ( Stroeve et al. 2014) and through 2015 ( Hamilton & Stroeve 2016). Here, I bring those analyses up to date with data through 2020. The main conclusions from earlier papers have proven to be robust, but unexpected new insights emerged as well. The long term downward trend in ice extent is reasonably well described as linear (R2 = 0.79) or quadratic (R2 = 0.81). Very large changes from the previous year’s extent in 2012 and 2013 resulted in the largest prediction errors. Both errors reflect one 2012 cyclone. For reasons not yet understood, SIO predictions especially those from dynamic modeling predict the previous year’s extent rather than the current year.  more » « less
Award ID(s):
1748325
PAR ID:
10207507
Author(s) / Creator(s):
Date Published:
Journal Name:
American Geophysical Union
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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