Satellite Detection of Arctic Sea Ice Leads

A new method to detect and characterize sea ice leads (fractures) has been developed using reflective and emissive satellite channels.  First, ice concentration is derived in cloud-free regions and used to create a mask of potential lead pixels. Then an algorithm identifies and characterizes leads with a combination of image processing techniques that examine shape characteristics. Data from the Moderate Resolution Imaging Spectroradiometer (MODIS) are used to assess the spatial and temporal distributions of Arctic sea ice leads since 2002. Sea ice leads play a critical role in the exchange of mass and energy between the ocean and atmosphere in the polar regions, particularly in the Arctic. Given the rapid thinning and loss of Arctic sea ice over the last few decades, changes in the distribution of leads can be expected in response. Leads are largely wind driven, so their distributions will also be affected by the changes in atmospheric circulation that have occurred. From a climate perspective, this new product can be used to identify trends in lead characteristics (width, orientation, and spatial distribution). From an operational perspective, knowledge of lead characteristics can aid in navigation, with direct benefits to security, subsistence hunting, and recreation.