Electromagnetic-laser for ice thickness data Video-Laser for lead and floe size distributions ArcticNet 2013 Leg 1b Ice Observations with helicopter sensors and electromagnetic (EM) sled Simon Prinsenberg CEOS Electromagnetic Sled Electromagnetic-laser sensor for Line profiles of ice thickness and surface ice roughness Some specifications of Electromagnetic-laser - 1.7, 5.0, 11.7 and 35.1 kHz - EM Footprint 30-35m - t= 10Hz x= 4-5m - Flying at 80mph at 5m height How??? Samples 10 times per second Laser data = distance to surface Electromagentic = distance to ocean surface From the two distances = snow+ice thickness Laser alone gives surface roughness every 4m Use of the data 1. Mean ice volume across Kennedy Channel -Data collected at three latitudes along Channel 2. Estimate ice volume flux and its variability with the use of ice drift from beacons and remote sensing and compare to ocean flux 3. Atmosphere-Ice-ocean interaction processes and input to ice-ocean modelling (pack ice evolution and its variability) 4. Assist in enhancing interpretation of remotely sensed data for ice chart production (Canadian Ice Service) Raw data: Total flight path - 140km long - ice thickness plotted up to 6m note mean includes open water is 1.2m but sensor saw 32% open water areas Ice thickness Distance scale (km) Ice thickness profile (3km) with laser plotted upwards and EM plotted downwards - map section in green shows where the data is from and - histogram show the ice thickness distribution sampled Scale 3km Open water Section of data plotted sampled floe by others next slide 400m On-ice sampling 5 passes over Sampled floe Note the floes are not sampled in same direction last two profiles on earlier flight and floe appears to have moved and rotated ship Four floes with water in between (39% of track shown) 130m 200m Video mosaics flown at 130m and 200m height For floe size distribution and lead width and direction Electromagnetic-GPS Sled - for ice thicknesses on floes - no laser samples 1/sec - Sept 1, 2013 Raw EM sled data collected by being towed with skippy boat Three flat line sections are sampling locations for ice thickness samples through auger holes Floe drift Ice thickness line profiles collected by EM sled towed by Skippy boat Floe drift