Leads are linear, crack-like openings in the sea-ice cover. The size of Arctic leads typically ranges from 50 m to several kilometers in width and several kilometers to several hundreds of kilometers in length. We use satellite observations from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) to infer lead orientations. The spatial resolution of the AMSR-E measurements allows for detecting larger leads with a minimum width of 3 km.
The figure above shows the good agreement between large leads detected via passive remote sensing from AMSR-E measurements and leads detected via active remote sensing from Advanced Synthetic Aperture Radar (ASAR) measurements north of Greenland on 14 March 2011. The figure below shows the Arctic-wide mean spatial distribution of lead orientation and frequency for the winters from 2002 to 2011. Each line represents the mean lead orientation in a cell of 100 km x 100 km size. The grey scale shows the number of detected leads within the cell, while the width of the line represents the standard deviation of the lead angles, which is a measure for the variability of lead orientations in the cell.
For more informations:
Bröhan, D. and Kaleschke, L. (2014), A Nine-Year Climatology of Arctic Sea Ice Lead Orientation and Frequency from AMSR-E. Remote Sensing, 6, 1451-1475; doi:10.3390/rs6021451