Ron Kwok Jet Propulsion Laboratory California Institute of Technology Critically Needed: Continued 3-day RADARSAT coverage of the Western Arctic Ocean during IPY

2 6/28/2015 RK 3-day RADARSAT mapping of Arctic Ocean RADARSAT has been providing 3-day mapping of the Arctic Ocean for derivation of small-scale ice kinematics since Nov 1996 These observations: Provide unprecedented spatial sampling of Arctic sea ice drift and deformation Support IPY field programs Are crucial for process studies, model validation, model development, and climate analysis Together with Envisat, provide basin scale coverage of the Arctic Ocean These routine 3-day observations (through the Alaska Satellite Facility) will not be available to the science community after March 2008 (end of CSA/NASA MOU) These observations are critical for supporting IPY science and operations in 2008 and 2009 The gap in IPY coverage may be to big to be filled by other SARs at this time

Arctic Ocean Coverage 24-day RADARSAT orbit cycle RADARSAT ScanSAR wide B (460 km swath) 3-day repeat coverage within ASF reception mask 6-day repeat coverage within Tromso reception mask Acquistion since Nov 96 Gap in Data set: Antarctic Mapping Campaign: Aug- Oct,97 ~650 mins of SAR data/cycle More than 500 images 3-day coverage

4 6/28/2015 RK Mapping of time-varying deformation in the ice cover 10 1 km 10 3 km Initial Grid resolution: 10 by 10 km Drift tracks ~10 km separation (initially) sampled 1-3 days for two-thirds of the Arctic Ocean for an entire winter RADARSAT Geophysical Processor System (RGPS) 10 2 km

5 6/28/2015 RK Time-varying deformation (Divergence)

6 6/28/2015 RK Model Comparisons using RADARSAT ice drift from RGPS NOV APR