Ron Kwok Jet Propulsion Laboratory

California Institute of Technology

Critically Needed:Continued 3-day RADARSAT

coverage of the Western Arctic Ocean during IPY

204/18/23 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 Coverage24-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

404/18/23 RK

Mapping of time-varying deformation in the ice cover

101 km 103 km

Initial Grid resolution: 10 by 10 kmInitial Grid resolution: 10 by 10 km

Drift tracks ~10 km separation (initially) sampled 1-3 days for two-thirds of the Arctic Oceanfor an entire winter

RADARSAT Geophysical Processor System (RGPS)

102 km

504/18/23 RK

Time-varying deformation (Divergence)

604/18/23 RK

Model Comparisons using RADARSAT ice drift from RGPS

NOV APR