Navigability Indicators for the Northwest Passage and the Northern Sea Route

The U.S. National Climate Assessment (NCA) issues periodic reports that include “indicators” of the status and trends of various climate processes and their ecological importance.  We have developed navigability indicators for possible inclusion in the NCA.  These indicators quantify the extent to which the Northwest Passage (NWP) and the Northern Sea Route (NSR) are open to navigation due to the presence or absence of sea ice.  The indicators have been calculated from June 2002 through fall 2016 using daily sea-ice concentration products derived from satellite passive microwave data from the AMSR-E and AMSR-2 instruments.  The indicator for a given shipping route is a time series of the percentage of the route’s length that is free enough of sea ice to allow the passage of a ship.  We present results for several routes through the NWP and NSR.  In addition, we map the home ranges of several Arctic marine mammal species and identify key areas of their habitat that intersect the shipping routes, to see which species might be disproportionately impacted by increased shipping and industrial development.