2014 Sea Ice Outlook: July Report


Arctic sea ice influences the earth's climate. Image from CorelDRAW. Source: National Snow and Ice Data Center (NSIDC) Since 2008, the annual Sea Ice Outlook (SIO) has provided an open process for those interested in arctic sea ice to share ideas about the September minimum sea ice extent. This year (2014) represents a transition for the SIO, as it is now managed as part of the Sea Ice Prediction Network.

The SIO produces reports in June, July, and August containing a variety of perspectives on arctic sea ice---from observations of current conditions, to advanced numerical models, to qualitative perspectives from citizen scientists. A post-season report will provide an in-depth analysis of factors driving sea ice extent this summer as well as explore the scientific methods for predicting seasonal ice extent. Here is the Executive Summary from the July Report, published July 23, 2014:

Figure 1. Distribution of individual Pan-Arctic Outlook values (July Report) for September 2014 sea ice extent (labels on the bar graph are rounded to the tenths for readability. Refer to the Individual Outlooks at the bottom of this report for the full details of individual submissions). Source: Arcus.org

The July Outlook report was developed by Walt Meier, NASA Goddard Space Flight Center, and the rest of the SIPN leadership team, with a section analyzing the model contributions by François Massonnet, Université Catholique de Louvain.

The median Outlook value for September 2014 sea ice extent is 4.8 million square kilometers with quartiles of 4.4 and 5.0 million square kilometers. Thus, the median value is slightly higher than the June value (4.7) and the distribution of Outlooks is slightly reduced relative to June. The overall range is now from 3.2 to 5.9 million square kilometers. These values compare to observed values of 4.3 million square kilometers in 2007, 4.6 million square kilometers in 2011, 3.6 million square kilometers in 2012, and 5.4 million square kilometers in 2013.

Sea ice declined at a pace more rapid than normal during June, particularly late in the month when extent decreased by over 100,000 square kilometers per day. The decline has since slowed somewhat.

igure 2. Distributions of June (left) and July (right) 2014 Outlook contributions as a series of box plots, broken down by general type of method. The box color depicts contribution method. A fifth box appeared in the June report separating out the modeling contributions that used both data assimilation and fully coupled modeling to arrive at their prediction. However, in July the number (n=3) of this type was too small to show as a distribution. Source: Arcus.org

The Sea Ice Outlook is a venue for discussion and networking and provides a transparent exercise in both scientific sea ice predictions as well as estimates from the public. The post-season activities will provide more of a scientific analysis of the methodologies, relative performance, etc.

This month's full report includes the comments on modeling outlooks and on regional predictions, a summary of current conditions, key statements from each Outlook, and links to view or download the full outlook contributions.