Robert Ezraty

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The Synergy of Active and Passive Sensors for
Arctic Sea Ice Monitoring

• Robert Ezraty Fanny Girard-Ardhuin
• IFREMER France
• Robert.Ezraty_at_ifremer.fr Fanny.Ardhuin
  _at_ifremer.fr
• http//www.ifremer.fr/cersat

Photo Nick Hugues
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Outline

• WWWWW W ?????

• Where are we located ?

• What are we dealing with? (sensors)

• When ?

• Which sea ice parameters ?

• Why (Climate Variability) ?

• Wrap up-Conclusions

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µ-wave Radiometer
Scatterometer Ice extent and Concentration
Ice type
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Initial Multi-Year Sea Ice ExtentSeptember
1999-2005Radiometer Scatterometer
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Three-day Sea Ice Drift Merged Scatterometer
Radiometer drifts
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Lagrangian validation of sea ice drift
Sept. 15, 2002- March 31, 2003 Buoy 25499
Sept. 1, 2003- Dec..31, 2003 Buoy 24289
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Drift vector density
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Sea Ice Parameters

• Sea ice Types (MY-FY-New Ice)
• Scatterometer ( Radiometer)
• Sea ice Concentrations
• Radiometers (SSM/I 85GHz, AMSR-E 89GHz)
• Sea ice Drift
• Optimal combination of
• Scatterometer Radiometers estimates
• (QuikSCAT SSM/I)

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Sea Ice as a Climate Change Indicator of Global
Warming?
Long term trend is OK 18 decrease for the last
26 years but Winter Variations?
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Multi Year sea ice area evolution Winter
2004-2005
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The sea ice driftDec. 2004 Jan Feb 2005
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Multi-Year Sea Ice Area
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Wrap up-Conclusions

• The joint use of Scatterometer and Radiometer for
  monitoring Arctic Sea Ice
• Improves the quality of the geophysical data
• Improves the confidence in the geophysical data
  set
• Eases interpretation of geophysical results
• Provides correct insight on sea ice climate
  variability
• Whole data set available from
• http//www.ifremer.fr/cersat/
• ASCAT on METOP(S) 2006?2020