GOCINA ' OCTAS ' and

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GOCINA . OCTAS . and
ARCGICE   Combination of Spaceborne, Airborne and
In-Situ Gravity Measurements in Support of
Arctic Sea-Ice Mapping   A proposal for ESA
EOP-SM/1090 (1/6/04)   by   R. Forsberg (PI)1, O.
B. Andersen1, P. Knudsen1, S. W. Laxon2, J.
Johannesen3, C. C. Tscherning4, A. Braun5
  1National Survey and Cadastre / Danish Space
Centre, Denmark (KMS) 2Centre for Polar
Observation and Modeling, Univ.College London, UK
(UCL)
3Nansen Centre for Environmental Research,
Norway (NERSC) 4Niels Bohr Institute of
Astronomy, Physics and Geophysics, University of
Copenhagen, Denmark (UCPH)
5Department of Geomatics Engineering, University
of Calgary, Canada (UoC)
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Sea-ice change submarine and ERS observations
Sea-ice altimetry measurement h N
T MDT F T tides MDT mean dynamic
topography F Freeboard height (
thickness/6.0) N Geoid
Of special interest F sea-ice is thinning!
(Laxon et al., Rothrock et al)
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Sea-ice seasonal cycles
Thickness 2-4 m First year ice (thinner)
Multi-year ice (thicker)
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Sea-ice north of Greenland
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Sea-ice north of Greenland (MODIS imagery)
Area north of Greenland May 2004 (unusually
large drift approx 0.5 knots) C\rf\powerpt\cry
ovex_final \modisgif From L. Toudal, DTU
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The sea-ice is diminishing
HMS Tireless på Nordpolen, April 2004
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Cryosat ESAs first polar radar altimetri
satellite
ESA Doppler altimetri satellite launch May 2005
700 km height, 92º inclination
Goals of CRYOSAT measuring trends
CRYOSAT
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NASA ICESat laser, allready in orbit
ICESat Ice, Cloud and Elevation Satellite
NASA laser satellite launch Jan 2003 600 km
orbit, 94º inclination
Example of ICESat h Arctic track
Baffin Bay details
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ARCGICE goals

• Collect and validata existing freeboard
  measurements (ERS, ICESat)
• Make new highly accurate geoid ArcGP data and
  GRACE
• .. Include error estimates and spectral
  resolution
• Make best possible Arctic tidal models
• MDT models and observations of the Arctic Ocean
• Make smart interpolator to determine mean sea
  surface for Cryosat
• Time frame 18 months

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ArcGICE WPs
 
 
 
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Elements of ARCGICE
ArcGP gravity (Forsberg Kenyon)
ERS freeboard heights (Laxon)
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ARCGICE and tidal amplitudes
(S. Laxon, UCL)
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Mean Sea Surface and geoid
ArcGP geoid
ERS (Laxon)
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MDT model - PIPS / NPS
Courtesy Wieslaw Maslowski, NPS
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ARCGICE A Mean Sea Surface (MSS) for CryoSat?
Arctic GP Geoid
High Arctic MSS
PIPS Dynamic Topography
Arctic MSS
CryoSat Global MSS
81.5 N
ERS MSS
60 N
CLS MSS